“Lure and kill” technology has been used for several decades in pest management and eradication of invasive species. In lure and kill, the insect pest attracted by a semiochemical lure is not “entrapped” at the source of the attractant as in mass trapping, but instead the insect is subjected to a killing agent, which eliminates affected individuals from the population after a short period. In past decades, a growing scientific literature has been published on this concept. This article provides the first review on the potential of lure and kill in long-term pest management and eradication of invasive species. We present a summary of lure and kill, either when used as a stand-alone control method or in combination with other methods. We discuss its efficacy in comparison with other control methods. Several case studies in which lure and kill has been used with the aims of long-term pest management (e.g., pink bollworm, Egyptian cotton leafworm, codling moth, apple maggot, biting flies, and bark beetles) or the eradication of invasive species (e.g., tephritid fruit flies and boll weevils) are provided. Subsequently, we identify essential knowledge required for successful lure and kill programs that include lure competitiveness with natural odor source; lure density; lure formulation and release rate; pest population density and risk of immigration; and biology and ecology of the target species. The risks associated with lure and kill, especially when used in the eradication programs, are highlighted. We comment on the cost-effectiveness of this technology and its strengths and weaknesses, and list key reasons for success and failure. We conclude that lure and kill can be highly effective in controlling small, low-density, isolated populations, and thus it has the potential to add value to long-term pest management. In the eradication of invasive species, lure and kill offers a major advantage in effectiveness by its being inverse density dependent and it provides some improvements in efficacy over related control methods. However, the inclusion of insecticides or sterilants in lure and kill formulations presents a major obstacle to public acceptance.

A regional survey of the complex tritrophic associations (parasitoid-aphid-plant) of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) was carried out to determine and explore the patterns of those associations in various types of environments. Here, we present trophic relationship patterns of the five aphid parasitoid species in crop and noncrop habitats in southeastern Europe, and we contrast them in a regional (Mediterranean [MED] versus continental [CNT]) context. In total, 79 aphid host taxa were identified in this survey. Forty-two of these were recorded from noncrop plants only, 21 from crop plants only, and 18 were present on both types of plants. This means that ≈74% of all the parasitoid-aphid trophic interactions that support the persistence of the five selected parasitoids are entirely (54%) or partially (20%) associated with noncrop plants. The correspondence of parasitoid-aphid combinations among habitat/region combinations is very high and specific. Our results suggest that Mediterranean and continental regions are clearly distinguished by a contrasting pattern of trophic interactions in crop habitats, whereas the noncrop habitats contribute in lesser degree to these differences. For the crop/noncrop breakdown, the number of nonspecific interactions was larger than expected in crop habitats, whereas in noncrop habitats the abundance of partially specific and specific interactions was larger. The analysis of variance for the regional and habitat distribution of mean aphid host number per parasitoid was highly significant. When both regions were analyzed separately, the parasitoid/crop design showed significant parasitoid effects as well as interactions, whereas the habitat effect was not significant for the Mediterranean region and highly so for the continental region. This highly complex pattern suggests that the mean number of parasitized aphid species is not distributed among parasitoids, regions, and habitats in a similar manner. Even with these complexities taken into account, the overall trend is that noncrop habitats support more parasitoid-aphid combinations and more so in the continental than in Mediterranean regions, although not always statistically significant. As mentioned, large number of noncrop aphid hosts, especially for Lysiphlebus fabarum (Marshall), Praon volucre (Haliday) and Aphidius colemani Viereck, can significantly enhance the population buildup for these important parasitoids around agroecosystems. These facts can be important in biological aphid pest control in the region. Although not easily quantified, the overall positive effects of larger parasitoid diversity in noncrop habitats are undoubtedly related to the distribution and structure of noncrop habitat patches in agroecosystems at a landscape scale.

Between 1914 and 2007, a quarantine protected California avocado, Persea americana Mill., groves from pests that might be introduced into the state along with fresh, imported avocados. Soon after Mexican avocados were first allowed entry on 1 February 2007, live specimens of several species of armored scales (Hemiptera: Diaspididae) not believed to be present in California were detected on ‘Hass’ avocados entering the state from Mexico. Initially, the California Department of Food and Agriculture (CDFA) prevented avocados infested with these scales from entering the state or required that they be fumigated with an approved treatment such as methyl bromide. After a Science Advisory Panel meeting in May 2007, U.S. Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS) reaffirmed its position that armored scales on shipments of fruit for consumption (including avocados) pose a “low risk” for pest establishment. In compliance with APHIS protocols, as of 18 July 2007, CDFA altered its policy to allow shipments of scale-infested avocados into the state without treatment. Here, we report on sampling Mexican avocados over an 8-mo period, September 2007–April 2008. An estimated 67 million Mexican Hass avocados entered California over this period. Based on samples from 140 trucks containing ≈15.6% of this volume of fruit, we estimate that ≈47.6 million live, sessile armored scales and an additional 20.1 million live eggs and crawlers were imported. We found eight probable species of armored scales in the samples, seven of these are not believed to occur in California; 89.3% of the live scales were Abgrallaspis aguacatae Evans, Watson and Miller, a recently described species. In contrast to the USDA-APHIS opinion, we believe the volume of shipments and levels of live scales they contain present a significant risk to California's US$300 million avocado industry and to other crops that might become infested by one or more of these exotic species.

There have been major structural changes in the beekeeping industry over the past 25 yr. The U.S. Census of Agriculture surveys indicate that colony inventory declined >20% between 1982 and 2002, whereas the number of U.S. farms with apiculture enterprises fell >70%. This decline in farm numbers was not uniform across different sized farms based on colony inventory—nearly 30,000 of the farms exiting the apiculture business had fewer than 25 colonies. With the number of farms declining faster than colony inventory, there has been a shift to larger farms. The Appalachia, Corn Belt, and Northeast states have the highest shares of apiculture farms, whereas the Pacific, Northern Plains, and Mountain states account for the largest shares of colonies. Farms with apiculture enterprises are concentrated in the smallest sales categories—87% of such farms had <$50,000 in sales in 2002. Only about one third of farms with apiculture activity reported that a majority of sales were from apiculture products—such as honey or colony sales. Compared with all U.S. farms, per farm payments for all types of government programs were smaller for farms with apiculture activities. Only about half of all beekeepers regard farming as their primary occupation, and nearly 60% of the operators work off the farm at least 1 d a year and ≈40% work >200 d off the farm in a given year. Beekeepers resembled all other farmers demographically—nearly 90% are white males, with an average age of 55.

Cotton hardlock caused by Fusarium verticillioides (Sacc. Nirenberg) can reduce cotton, Gossypium hirsutum L., yields >70% in the southeastern United States. The spores infect flowers on the day of pollination, resulting in hardlock, which is the failure of the fiber to fluff as the boll opens at maturity. Frankliniella spp. Thrips (Thysanoptera: Thripidae) inhabiting the flowers are hypothesized to increase hardlock by spreading the conidia or by creating entranceways for the germinating Fusarium conidia. Experiments were conducted at Marianna and Quincy in Florida in 2006 and 2007 to determine whether there was a relationship between the number of adult and larval thrips inhabiting the flowers of cotton and the incidence of cotton hardlock. Frankliniella tritici (Fitch) was >98% of the adult thrips in the samples at both locations each year. The adults of Frankliniella bispinosa (Morgan) and Frankliniella occidentalis (Pergande) also were collected. There were no significant regression relationships between weekly mean densities of thrips in the flowers and the incidence of cotton hardlock at harvest in any of the experiments. Additional experiments were conducted at each location in 2006 and 2007 to determine whether weekly applications during flowering of the insecticide lambda-cyhalothrin, the fungicide thiophanate methyl, and the combination of the two reduced the incidence of cotton hardlock at harvest. Applications of the insecticide significantly reduced the numbers of adult F. tritici, the number of thrips larvae, and the incidence of hardlock at harvest. Applications of the insecticide were as affective as applications of the insecticide plus fungicide. In one experiment, applications of the fungicide reduced the incidence of hardlock at harvest. Applications of the insecticide usually significantly increased the number of adult F. occidentalis. None of the pesticide treatments significantly affected the numbers of the key thrips predator Orius insidiosus (Say). We conclude that insecticidal control of the adults and larvae of F. tritici during flowering reduced the incidence of cotton hardlock. However, there were no significant regression relationships between the incidence of cotton hardlock at harvest and the number of thrips in the flowers.

Field and laboratory experiments were carried out on the island of Oahu, HI, to compare the susceptibility of the two most commonly grown banana (Musa sp.) cultivars in the state (‘Dwarf Brazilian’or Santa Catarina [locally known as dwarf apple] and ‘Williams’) to the aphid-borne Banana bunchy top virus (genus Babuvirus, family Nanoviridae, BBTV). Several morphological and physiological features of the two cultivars were monitored to determine whether the banana aphid, Pentalonia nigronervosa Coquerel (Hemiptera: Aphididae), transmits BBTV to both cultivars at a similar rate; and whether after successful inoculation, does each cultivar respond similarly to viral infection. Results from the laboratory experiment showed that a similar percentage of both cultivars were infected with BBTV by aphid vectors (>90% for both cultivars). However, field results showed a significantly lower percentage of dwarf apple (39%) infected with BBTV compared with Williams (79%). We also found that all physiological and morphological features measured (i.e., plant height, leaf area, canopy, chlorophyll level, and moisture content) for both cultivars were impacted similarly by BBTV. The incubation period, or the time between plant infection and initial appearance of disease symptoms, was similar for both cultivars. Results also showed that BBTV transmission efficiency was lower in the field than in the laboratory, despite that more aphids per plant were used for field than laboratory inoculation tests. The results highlight the potential use of less susceptible cultivars to help manage BBTV and the importance of screening banana varieties in the field to determine their response to vectors and associated diseases.

Haeckeliania sperata Pinto is an egg-endoparasitoid of Diaprepes abbreviatus L. (Coleoptera: Curculionidae). We evaluated the relative susceptibility of H. sperata adults to commercially relevant pesticides used in citrus and ornamental production systems. Parasitoids were exposed to pesticide residues on leaf surfaces. Four concentrations of seven pesticides were tested; concentrations for each pesticide consisted of a dilution series using the label rate for field applications as the starting concentration. Lethal concentrations (LC₅₀s and LC₉₀s) were calculated 12 and 24 h after exposure to the pesticides. Lethal times (LT₅₀s and LT₉₀s) were estimated for each pesticide concentration. All tested pesticides had a negative effect on Haeckeliania's survivorship. However, some pesticides were significantly less harmful to this parasitoid. LC₅₀s and LC₉₀s of organophospate, carbamate, and pyrethroid pesticides were less than one eighth of the label rates. LT₅₀S and LT₉₀S of these insecticides were <12 h even at the most diluted concentrations. Thus, applications of these pesticides might have a strong negative impact on the natural control of D. abbreviatus by H. sperata. Commercial formulations of imidacloprid, abamectin, petroleum oil, and a phosphonate fungicide allowed H. sperata to live longer compared with the previous pesticides, suggesting a certain degree of selectivity. Moreover, adults exposed to diluted concentrations of imidacloprid, abamectin, petroleum oil, and a phosphonate fungicide had a greater survival than those exposed to label concentrations. These findings suggest that the use of products that have less toxic effects on the introduced parasitoid will increase its chances to parasitize D. abbreviatus eggs.

At least 26 different species of insects of quarantine significance were intercepted from 1985 to 2005 on bamboo (Bambusa spp.) garden stakes from China. Three fifths of the live insects were cerambycids in nine genera, including Chlorophorus annularis F., the bamboo borer. The current APHIS-PPQ treatment is fumigation schedule T404-d, which requires high doses of methyl bromide (MeBr) for 24 h. No specific fumigation data exist for C. annularis. Chinese and American quarantine scientists cooperated in testing to determine whether this schedule, or lower doses, would be effective as a quarantine treatment for C. annularis infesting dried bamboo poles. A lower dose based on APHIS tests for solid wood packing (SWP) failed (3/511 survivors) at 56 g/m³ for 24 h at 10.0°C. We therefore tested five progressive doses at five temperatures intermediate between the lower SWP schedule and the much higher applied doses (e.g., 120 g/m³ for 24 h at 10.0°C) of schedule T404-d. Fumigations of infested bamboo poles conducted in 403.2-liter chambers with 52% vol:vol loading at doses of 48, 64, 80, 96, and 112 g/m³ at 26.7, 21.1, 15.6, 10.0, and 4.4°C, respectively (20 total replicates, with 4 replicates per dose), had no survivors among 2,847 larvae, 140 pupae, and 122 adults. Control replicates (three) had a total of 455 live stages (397 larvae, 31 pupae, and 27 adults). Tests conducted with a sea/land cargo container loaded to 80% capacity with bamboo poles verified the ability of the schedule to maintain effective concentrations over 24 h in commercial-sized fumigations. We propose a new bamboo quarantine treatment schedule at reduced rates of applied MeBr.

The physiological basis for host antibiosis or nonpreference to a quarantine pest is often not understood. Studies are needed on the mechanisms that impart resistance to better understand how resistance might fail. Experiments were conducted to examine the infestability of ‘Sharwil’ avocados by oriental fruit fly, Bactrocera dorsalis (Hendel), and Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), after harvest and to quantify the effect of avocado skin hardness on resistance to infestation by oriental fruit fly. Infestation rate increased with decreasing fruit firmness, but fruit were generally poor hosts. Fruit with a patch of skin removed produced more flies than intact fruit, suggesting that skin puncture resistance was an important deterrent to oviposition. This study showed that fruit can be infested within 1 d after harvest, suggesting that fruit should be transferred to fruit fly-proof containers as they are harvested to minimize the risk of attack. Although risk of infestation is negatively correlated with fruit firmness, even some hard fruit may become infested. Therefore, fruit firmness cannot be used alone as an indicator to ensure fruit fly-free ‘Sharwil’ avocados. Measuring fruit firmness may be a useful component of a multiple component systems approach as an additional safeguard to reduce risk of infestation.

Black vine weevils, Otiorhynchus sulcatus (F.) (Coleoptera: Curculionidae), are serious pests of container- and field-grown nursery crops. Management programs usually target the larval stage in container-grown plants and the adults in field-grown plants. We tested several new systemic insecticides for efficacy against black vine weevil in container-grown Sedum spp. and field-grown Taxus spp. In 2006 and 2007, clothianidin, dinotefuran, and chlorantraniliprole were applied as surface drenches to containerized Sedum plants, and suppression of larval densities and adult feeding were evaluated. Sedum leaf bioassays were used to further examine the influence of clothianidin, dinotefuran, and chlorantraniliprole on adult feeding. In 2006, pots were infested with adult black vine weevil 1 d after treating, and in 2007 pots were infested 1 or 43 d after treating. All three insecticides significantly reduced the numbers of larvae in 2006, but not in 2007, because of low numbers of larvae in the untreated control plants. Dinotefuran and clothianidin reduced feeding by adult black vine weevil on containerized Sedum plants, resulting in more blossoms, fewer damaged leaves, and a lower percentage of leaves damaged compared with control plants. In bioassays with detached leaves, all three insecticides reduced feeding compared with control plants. Efficacy and timing of clothianidin, imidacloprid, and acephate soil drenches and imidacloprid and acephate soil injections were evaluated for black vine weevil control over a 1-yr period in field-grown Taxus plants. All insecticide treatments significantly reduced the numbers of larvae in field-grown Taxus plants compared with control plants; and all but the spring acephate drench improved the appearance of the Taxus (foliar rating) plants compared with untreated plants. All of the tested insecticides showed potential for preventing infestations of black vine weevil larvae and reducing feeding by the adults in ornamental plants.

Traps containing a combination floral and synthetic pheromone lure are used to monitor and manage Japanese beetles, Popillia japonica Newman (Coleoptera: Scarabaeidae). One key factor limiting trap effectiveness for beetle control is the “trap spillover” phenomenon, in which the trap attracts beetles without capturing them, resulting in increased damage to surrounding host plants. We investigated the mechanisms underlying trap spillover by conducting two studies in a soybean field in east central Illinois. In the first study, we set up trap stations for 1 d and compared the sex, size, and egg load (for females) of beetles caught in the traps with those on the plants immediately surrounding the trap, downwind of the trap, at lure-only (no trap) stations, and at control areas. Females caught in traps tended to be smaller than those on plants surrounding the traps, and females attracted to the traps had fewer eggs than those downwind or at control sites. We did not find any difference in male characteristics. In the second study, we observed the behavior of beetles initially approaching traps. Upon initial approach, the majority of individuals landed on plants before making contact with the trap, and those beetles that spent an extended time on the leaves tended to be females. Arriving males would occasionally pair with these females on the plants. Overall, traps did not capture a random subset of the beetles present in the field. We hypothesize that trap spillover is a result of arriving females not being as attracted to the precise location of the trap as they are to the general location itself, and of arriving males seeking mates and finding them among these spillover females.

A simple method of marking Mediterranean fruit fly Ceratitis capitata (Wiedemann) using stable isotopes is described. This species is economically important and is a target species of many successful area-wide integrated pest management (AW-IPM) programs using the sterile insect technique (SIT). Program monitoring in the field relies on being able to accurately differentiate released sterile insects from wild insects so that estimates can be made of the ratio of sterile males to wild males. Typically, released flies are marked with fluorescent dust, which is not always reliable. The difference in isotopic signatures between wild and factory-reared populations could be a reliable and intrinsic secondary marker to complement existing marking methods. Isotopic signatures are natural differences in stable isotope composition of organisms caused by discrimination against the heavier isotopes during some biological processes. The isotopic signature of an organism is mainly dependent on what it eats; by feeding factory-reared flies isotopically different diets to those of the wild population, it is possible to intrinsically mark the flies. The majority of fruit fly species feed on C3 plants in the wild, which have a carbon isotope signature of around -28‰. However, almost all mass-rearing facilities use cane sugar in the larval and adult diet, which is a C4 sugar source (with a signal of around -11‰), and this could provide an easy signature to differentiate released flies from wild flies. To test this approach, samples of flies from several mass-rearing facilities and wild populations were analyzed. It was clearly shown that using C4 sugar in the larval-rearing diet was an effective and economic way of intrinsically labeling Mediterranean fruit flies, and it was possible to distinguish mass-reared from wild populations with >95% confidence. The C4 marker was detectable and distinguishable from wild populations up to 12 d after “release.” This technique could be adopted for use in any other SIT program with similar rearing protocols to Mediterranean fruit fly.

The carob moth, Ectomyelois ceratoniae (Zeller), infests different date, Phoenix dactylifera L., fruit stages during the summer months in southern California. Abscised fruit in the kimri stage become heavily infested when they get stuck in tight date bunches and do not fall to the ground. Previous work on date palm horticulture found that the percentage of fruit abscission could be reduced by thinning fruit out of the bunch. Our objective in this study was to determine whether center cut strand thinning reduced fruit abscission and, if so, to determine any concurrent effect on carob moth summer population densities. We found that the center cut treatment did not alter fruit abscission at any of the four date gardens used in the study. However, thinning in May reduced July carob moth densities at the four date gardens by 54–97%. The percentage reduction was apparent into September, ranging from 30 to 81%. This reduction was significant in two of the four fields, and we believe that center cut thinning in these fields altered the bunch architecture, allowing abscised fruit to fall to the ground. Implications for field management of the carob moth are discussed.

The West Indian fruit fly, Anastrepha obliqua (Macquart), is considered one of the most important pests of several fruit crops in Latin America. Studies on the sensorial ecology of A. obliqua may contribute to the improvement of a trapping system for monitoring this fruit fly species. In this study, we investigated the responses of both sexes of A. obliqua to different visual cues and to the combination of visual and chemical cues in field cages tests. Both sexes were more attracted to lime-green, orange, and yellow spheres than to red, black, or white spheres. Flies were more attracted to three-dimensional models than to flat models. A. obliqua was more attracted to 8-, 10-, and 12-cm-diameter spheres than to 4- and 6-cm-diameter spheres. Flies were more attracted to lime-green spheres baited with mombin fruit odor, Spondias mombin L., than to spheres offering either visual or cues alone.

A 2-yr study was conducted in a citrus orchard (Citrus sinensis L. Osbeck cultivar Valencia) to determine the influence of plant water stress on the population dynamics of glassy-winged sharpshooter, Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop evapotranspiration rate (ET_c) and continuous deficit-irrigation regimens at 80 and 60% ET_c. Microclimate and plant conditions monitored included temperature and humidity in the tree canopy, leaf surface temperature, water potential, and fruit quality and yield. Glassy-winged sharpshooter population densities and activity were monitored weekly by a combination of visual inspections, beat net sampling, and trapping. Glassy-winged sharpshooter populations were negatively affected by severe plant water stress; however, population densities were not linearly related to decreasing water availability in plants. Citrus trees irrigated at 60% ET_c had significantly warmer leaves, lower xylem water potential, and consequently hosted fewer glassy-winged sharpshooter eggs, nymphs, and adults than trees irrigated at 80% ET_c. Citrus trees irrigated at 100% ET_c hosted similar numbers of glassy-winged sharpshooter stages as trees irrigated at 60% ET_c and a lower number of glassy-winged sharpshooter nymphs than the 80% ET_c treatment, specifically during the nymphal density peak in mid-April to early July. Irrigation treatments did not affect populations of monitored natural enemies. Although the adult glassy-winged sharpshooter population was reduced, on average, by 50% in trees under severe water stress, the total number of fruit and number of fruit across several fruit grade categories were significantly lower in the 60% ET_c than in the 80 and 100% ET_c irrigation treatments.

The American grapevine leafhopper, Scaphoideus titanus Ball (Hemiptera: Cicadellidae), is the vector of the phytoplasma that causes Flavescence dorée, one of the most threatening grapevine yellows disease. The role of olfaction in host plant detection of this species is still unknown. In this study, the attractiveness of a host plant, the grapevine rootstock Vitis riparia × rupestris 101/14, to nymphs was verified through behavioral bioassays in a vertical glass Y-olfactometer. Furthermore, the olfactory sensitivity to odors extracted from grapevine organs headspace and the external morphology of the antennae were studied by electroantennography (EAG) and scanning electron microscopy (SEM), respectively. Headspace collections were made from fresh apical shoots and leaves. Concentrated extracts were analyzed by coupled gas chromatography and mass spectrometry (GC-MS) to identify volatile compounds. In EAG experiments, weak responses to plant odors were recorded. SEM observations indicated the presence of few antennal sensilla, potentially associated with olfaction. Our results suggest that olfactory cues may play a role in the host plant detection of S. titanus nymphs.

Bactrocera invadens Drew, Tsuruta & White (Diptera: Tephritidae) invaded Kenya in 2003. Before the arrival of B. invadens, the indigenous fruit fly species Ceratitis cosyra (Walker) was the predominant fruit fly pest of mango (Mangifera indica L.). Within 4 yr of invasion, B. invadens has displaced C. cosyra and has become the predominant fruit fly pest of mango, constituting 98 and 88% of the total population in traps and mango fruit at Nguruman, respectively. We tested two possible mechanisms responsible for the displacement namely; resource competition by larvae within mango fruit and aggression between adult flies. Under interspecific competition, larval duration in B. invadens was significantly shorter (6.2 ± 0.6-7.3 ± 0.3 d) compared with C. cosyra (8.0 ± 1.2-9.4 ± 0.4 d). Pupal mass in C. cosyra was affected by competition and was significantly reduced (7.4 ± 0.3-9.6 ± 0.6 mg) under competitive interaction compared with the controls (12.1 ± 1.5-12.8 ± 1.1 mg). Interspecific competition also had a significant adverse effect on C. cosyra eclosion, with fewer adults emerging under co-infestation compared with the controls. Interference competition through aggressive behavior showed that fewer C. cosyra (3.1 ± 0.8) landed on mango dome compared with the controls (14.2 ± 1.5) when adults were mixed with B. invadens adults in Plexiglas cages. Similarly the number of times C. cosyra was observed ovipositing was significantly lower (0.2 ± 0.2) under competitive interaction compared with the controls (6.1 ± 1.8). Aggressive encounters in the form of lunging/head-butting and chasing off other species from the mango dome was higher for B. invadens compared with C. cosyra. Our results suggest that exploitative competition through larval scrambling for resources and interference competition through aggressive behaviors of the invader are important mechanisms contributing to the displacement of C. cosyra by B. invadens in mango agroecosystems.

A semiochemical-based attractant for the tropical root weevil, Diaprepes abbreviatus L., has been sought since the introduction of this polyphagous pest to Florida in the 1960s. A six-unit wind tunnel apparatus was constructed to allow multiple runs to be conducted simultaneously to test the response of D. abbreviatus adults to volatile and contact semiochemicals. Arrestment was measured as the number of weevils stopping and remaining on a target when presented with upwind target choices. No response (movement upwind) was observed when weevils were presented with a control (no odor). Some movement upwind but no arrestment occurred when weevils were presented with young citrus leaves (flush). Citrus flush that had been fed on by D. abbreviatus adults was highly attractive and induced arrestment of both male and female adults. The effect was duplicated by placing organdy-enclosed feces (frass) on undamaged flush. The arrestment effect was eliminated, however, when fed-on flush was enclosed in a cage so that weevils could not contact the leaves. In these experiments, weevils continued to move upwind. The results of these tests lead us to conclude that host and mate location by D. abbreviatus is mediated by volatile and contact semiochemicals.

Effects of volatile odors from leek, Allium porum L., on the behavior of bean fly, Ophiomyia phaseoli (Tryon) (Diptera: Agromyzidae), were tested in laboratory olfactometer bioassays. Aqueous and solvent extracts (dichloromethane and methanol) of leek were repellent to adult flies. Whole leek plants were repellent and prevented attraction to the host plant, beans. Beans that had been exposed to volatiles from living leek plants for 7 d became repellent to the fly. Leek and several other crops were tested in field experiments to identify candidate crops for a mixed cropping system to minimize bean fly attack in beans, Phaseolus vulgaris L. In a wet season field experiment, mixed cropping of bean with leek or three other vegetable crops did not significantly reduce bean fly infestation or infection with Fusarium oxysporum Schltdl. compared with a mono crop, but significantly reduced plant death caused by both agents combined. In two dry season field experiments, mixed cropping of beans with leek significantly reduced adult bean fly settling, emergence, and death of bean plants compared with a mono crop. Bean yield per row was ∼150% higher for the mixed crop, and economic returns were approximately Sri Lankan Rs. 180,000/ha, higher than for the mono crop. For the mono crop, the farmer had a monetary loss, which would become a small profit only if the costs of family labor are excluded. The study is an example of the first steps toward development of sustainable plant protection in a subsistence system.

The wheat stem sawfly, Cephus cinctus Norton, causes severe losses in wheat grown in the northern Great Plains. Much of the affected area is planted in monoculture with wheat, Triticum aestivum L., grown in large fields alternating yearly between crop and no-till fallow. The crop and fallow fields are adjacent. This cropping landscape creates pronounced edge effects of sawfly infestations and may be amenable to trap cropping using existing agricultural practices. The behavioral preference for two wheat varieties was assessed in the context of developing trap crops for this insect. In field nurseries, stem lodging assessments indicated that the cultivar ‘Conan’ was infrequently damaged, whereas ‘Reeder’ was often heavily damaged. In laboratory choice and no-choice tests, ‘Reeder’ was significantly preferred by ovipositing wheat stem sawfly females. These two cultivars did not differ significantly in height or developmental stage, factors known to impact sawfly preference. Although Conan received fewer eggs than Reeder in no-choice tests, oviposition was further reduced in choice tests, indicating that females clearly preferred Reeder. In field trials where the overall dimensions of the spatial structure in choice tests was varied, females always selected Reeder over Conan in alternating block, row, and interseeded planting scenarios. Reeder releases greater amounts of the attractive compound, (Z)-3-hexenyl acetate than Conan but is similar to Conan for three other known, behaviorally active volatile compounds. The results are discussed in terms of cultivar selection for large scale trap crop experiments for the wheat stem sawfly.

Trichogramma Westwood (Hymenoptera: Trichogrammatidae) cause high mortality rates in the potentially resistant pest species, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), and are considered integral to the resistance management plan for Bacillus thuringiensis transgenic cotton, Gossypium hirsutum L., production in the Ord River Irrigation Area (ORIA), Western Australia. Measured as percentage of parasitism, Trichogramma activity seems highly variable over time; yet, it contributes significantly to pest suppression at peak insect pest density. Environmental constraints on Trichogramma survival, especially insecticide applications, may limit their effectiveness. The decision to initiate insecticide applications in ORIA cotton crops is best delayed unless absolutely necessary to avoid disruption of Trichogramma impact on pests. Trichogramma disperse into young crops and display high intrinsic rates of increase effectively stifling Helicoverpa (Hardwick) population increase after initial egg lay during high-density years in the ORIA, and evidence suggests a possible preference for H. armigera host eggs.

The psyllid Bactericera cockerelli (Sulc) (Hemiptera: Psyllidae) is the vector of a bacterial pathogen causing zebra chip (ZC) disease in potato, Solanum tuberosum L. (Solanaceae). Recently, ZC has become important to potato growers and the potato chipping industry in the southwestern United States, Mexico, Central America, and New Zealand. In the current study, we evaluated the knockdown effect of 12 insecticides against adult B. cockerelli, and we examined the effects of treating potato leaves: top side only, bottom side only, or both sides. Within 48 h of exposure, abamectin showed the highest and most consistent rate of adult B. cockerelli mortality and a dosage response to three dosages within labeled field rates. Choice tests conducted in petri dishes, involving untreated potato leaves and leaves treated with abamectin, revealed that abamectin did not affect host preference of adult B. cockerelli. A residual test under field conditions revealed that, although highly effective immediately after application, abamectin-effect was nonsignificantly different from control treatments 24 and 48 h after field application. Higher adult B. cockerelli mortality was recorded from potato plants treated with ground application compared with aerial 48 h after application. Our results indicated that abamectin has a high knockdown effect on adult B. cockerelli and that it can be used effectively in insecticide rotation programs against adult B. cockerelli and ZC control in potatoes.

Cionus latefasciatus Voss (Coleoptera: Curculionidae) is one of the most important insect pests on Scrophularia ningpoensis Hemsl. (Scrophulariales: Scrophuhrhceae), which is a well-known traditional Chinese medicine plant in southeast China. The biological characteristics and effects of temperature on the growth and development of C. latefasciatus were studied in nature, in the greenhouse, and in the laboratory. In the area studied, 9–12 generations of this weevil occurred per year depending on climatic conditions. The overwintered adults migrated to the plant-seeding fields in the earlier days of March, and adults of the last generation began to overwinter in early October. Female adults lived for 50–75 d and male adults for 50–65 d at 28°°C. Adults fed on leaves, buds, tender stems, and flower stalks during the entire developmental phase of the plant. Female adults began to lay eggs 2–4 d after emergence and laid an average of 330–390 eggs per female at 28°C. The eggs were usually laid on the surface of the leaves or into the leaves. The larvae have four instars judging from the width of the cephalic capsule of the larvae. The larvae fed on leaves and buds of the plant. Under constant temperatures (17, 20, 25, 28, and 30°C) and fixed humidity (75%), the development periods from egg to adult emergence were 36.91, 29.25, 19.11, 17.26, and 15.36 d, respectively, and 346.31 degree-days, in total, above a lower threshold of 7.7°C was required; the survival rates from egg to adult emergence were 49.1, 62.5, 72.0, 78.7, and 50.0%, respectively. Laboratory experiments showed that the optimum temperature for the development from egg to adult emergence was 28°C.

We conducted a 2-yr study to determine the effects of crop density and weeds on levels of damage caused by stalk-boring insects in rain-fed sunflowers in west-central Kansas. Weed-free sunflower had higher seed weight and oil content in 2007, but not in 2006, but weeds did not affect infestation by stalk-boring insects in either year. High-density sunflower had lower estimated seed yield per unit area than low-density sunflower in both years, but percentage oil was slightly greater in the high-density treatment in 2006. Sunflowers were more heavily infested by larvae of Ataxia hubbardi Fisher, Cylindrocopturus adspersus (Leconte), and Pelochrista womanana (Kearfott) in 2006 than in 2007, ostensibly as a result of being planted earlier. Larvae of Dectes texanus LeConte appeared unaffected by planting date and were present in >70% of plants in both years. Conditions during the period of crop maturity were much drier in 2006 than in 2007 and were associated with higher seed oil content and earlier and faster progression of stalk girdling by D. texanus larvae in both low- and high-density plots. There was also a strong effect of plant density on girdling behavior that seemed to be mediated by effects on soil moisture. Stalk girdling began earlier in high-density plots and a larger proportion of plants were girdled compared with low-density plots on all sampling dates in both years. Certain cultural tactics, in particular reduced plant spacing, have potential to delay the onset of girdling behavior by D. texanus larvae and thus mitigate losses that otherwise result from the lodging of girdled plants.

Twelve thousand to 16,000 ha of Louisiana sugarcane (Saccharum spp.) fields were flooded by saltwater from the Hurricane Rita storm surge in September 2005. A four treatment, 12-replication study comparing storm surge flooded and nonflooded plant and ratoon sugarcane fields was conducted during summer 2006 to assess sugarcane borer, Diatraea saccharalis (F.), pest severity, pest control actions, and soil-associated arthropod abundance and diversity. Even with a significant 2.4-fold increase in the average number of insecticide applications used for D. saccharalis management in flooded fields, growers still incurred higher injury. A significant 2.8-fold reduction in the predaceous red imported fire ant, Solenopsis invicta Buren, was associated with the storm surge, whereas no reduction in abundance of other soil-associated arthropods was recorded. Arthropod diversity measured by the Shannon diversity index significantly increased by a factor of 1.3 in sugarcane fields flooded by the storm surge. Increase in D. saccharalis pest severity associated with the storm surge caused an estimated loss in revenue between $1.9 and $2.6 million to the Louisiana sugarcane industry for the 2006 production season.

We evaluated the efficacy of systemic insecticides emamectin benzoate and fipronil for preventing mortality of individual loblolly pines, Pinus taeda L., as a result of attacks by southern pine bark beetles (Coleoptera: Curculionidae, Scolytinae) for two consecutive years in Mississippi (2005–2006) and Alabama (2006–2007). Trees were injected once in the spring of 2005 (Mississippi) or 2006 (Alabama) and then were baited with species-specific bark beetle lures several weeks later. The southern pine beetle, Dendroctonus frontalis Zimmermann, was the target species but was changed to Ips spp. in Mississippi (but not Alabama) the second year because of few southern pine beetle attacks on baited trees. Single injections of emamectin benzoate were effective in reducing tree mortality caused by bark beetles compared with untreated checks. Although less effective overall, fipronil also significantly reduced tree mortality from southern pine beetle compared with the checks during the second year in Alabama. Tree mortality continued well after the lures had been removed. Evaluations of bolts taken from experimental trees killed in 2006 indicated that emamectin benzoate effectively prevented parent bark beetle gallery construction and that fipronil significantly reduced lengths of galleries constructed by adult beetles, brood development, and emergence, compared with checks. In contrast, neither insecticide treatment prevented the bark beetles from inoculating blue stain fungi, Ophiostoma spp., into treated trees.

Species belonging to the genus Populus (poplars) produce a series of defensive proteins in response to insect damage. Proteinase inhibitors, polyphenol oxidases, and chitinases are the most relevant and intensively studied proteins. Most of the knowledge about the relation between these proteins and herbivores has been obtained from studies with chewing insects. Nothing is known about whether phloem-feeder insects such as aphids are able to trigger a comparable response. In the current study, the expression of genes encoding a Kunitz trypsin inhibitor 3 (KTI3), a polyphenol oxidase 1 (PPO1), and a class I chitinase (CHI) was characterized in two poplar hybrids (one resistant hybrid and one susceptible hybrid, to aphids) attacked by the aphid Chaitophorus leucomelas Koch. The expression pattern was analyzed using a semiquantitative reverse transcription-polymerase chain reaction approach. The expression of KTI3 was increased by aphids only in the aphid-susceptible hybrid. Differently, PPO1 expression was increased by aphids in the aphid-resistant hybrid. The expression of CHI was down-regulated by aphids in the susceptible hybrid. This is the first study to report the differential expression of poplar defense genes in response to phloem-feeder insects such as aphids. The findings from the current study suggest that the expression levels of defensive proteins are affected by poplar genotype and by aphid infestation.

Wood packaging material (WPM) is a major pathway for international movement of bark- and wood-infesting insects. ISPM 15, the first international standard for treating WPM, was adopted in 2002 and first implemented in the United States in 2006. ISPM 15 allows bark to remain on WPM after treatment, raising concerns that insects could infest after treatment, especially if bark were present. We conducted field studies to evaluate insect infestation of green logs and lumber with varying amounts of bark after heat treatment. In a log study, Cerambycidae and Scolytinae (ambrosia beetles and bark beetles) readily infested and developed in logs with bark after heat treatment. In a lumber study, Cerambycidae and bark beetles laid eggs in all sizes of bark patches tested (≈25, 100, 250, and 1,000 cm²) after heat treatment but did not infest control or heat-treated lumber without bark. Cerambycidae completed development only in boards with bark patches of 1,000 cm², whereas bark beetles completed development on patches of 100, 250, and 1,000 cm². Survival of bark beetles was greater in square patches (10 by 10 cm) versus rectangular patches (2.5 by 40 cm) of the same surface area (100 cm²). In surveys at six U.S. ports in 2006, 9.4% of 5,945 ISPM 15-marked WPM items contained bark, and 1.2% of 563 ISPM 15-marked WPM items with bark contained live insects of quarantine significance under the bark. It was not possible to determine whether the presence of live insects represented treatment failure or infestation after treatment.

The dogwood borer, Synanthedon scitula (Harris) (Lepidoptera: Sesiidae), is a serious wood-boring pest of apple in eastern North America. The recent identification of its sex pheromone and systematic documentation of the effect of a potent behavioral antagonist affords the opportunity to develop pheromone-based management strategies for this important pest. Here we evaluated the potential of pheromone-based mass trapping of males to reduce dogwood borer infestations and conducted preliminary evaluations of an antagonist-based pheromone blend for disruption of dogwood borer mate finding in commercial apple orchards in North Carolina, Virginia, and West Virginia. In the mass trapping study, treatments included a conventional trunk-drench application of chlorpyrifos, a low-density mass trapping regime of 5 traps/ha, a higher-density mass trapping regime of 20 traps/ha, and an untreated control. We removed large numbers of males from orchards at all locations, with 27,155, 8,418, and 7,281 removed from high-density trapping plots in North Carolina, Virginia, and West Virginia, respectively, over 2 yr. After 2 yr under each of these treatment regimes, infestation in high- and low-density mass trapping plots was not reduced to the level of chlorpyrifos-treated plots. An antagonist-based dispenser deployed at a rate of 250/ha effectively disrupted mate-finding by male dogwood borer. In plots with mating disruption dispensers, captures in pheromone-baited traps were virtually eliminated, and no males were captured in traps baited with virgin females.

Traditional chemical control against Chilo suppressalis Walker is currently being replaced in Spain by new methods based on pheromones. A key step to improve the efficacy of these methods is the determination of the optimum pheromone release rate, which is still uncertain for this pest. In this work, the pheromone release profile and the field performance of a new mesoporous dispenser was compared with a standard commercial dispenser. For this purpose, pheromone loads were extracted from field-aged dispensers and quantified by gas chromatography with flame ionization detector. In addition, a field trial was carried out with traps baited with one, two, or three mesoporous dispensers per trap, as well as with traps containing one standard dispenser. We found that the highest number of field catches did not correspond to the highest pheromone emission rate, which suggests a repellent effect of the insect if the emission is excessive. The results suggest that the attractant activity was maximized by emitting ∼34 µg/d. The efficacy of the mesoporous dispenser and its possible improvements are discussed.

Striped cucumber beetle, Acalymma vittatum F., is the primary insect pest of cucurbit crops in the northeastern United States. Adult beetles colonize squash crops from field borders, causing feeding damage at the seedling stage and transmitting bacterial wilt Erwinia tracheiphila Hauben et al. 1999. Conventional control methods rely on insecticide applications to the entire field, but surrounding main crops with a more attractive perimeter could reduce reliance on insecticides. A. vittatum shows a marked preference for Blue Hubbard squash (Cucurbita maxima Duchesne) over butternut squash (C. moschata Poir). Given this preference, Blue Hubbard squash has the potential to be an effective perimeter trap crop. We evaluated this system in commercial butternut fields in 2003 and 2004, comparing fields using perimeter trap cropping with Blue Hubbard to conventionally managed fields. In 2003, we used a foliar insecticide to control beetles in the trap crop borders, and in 2004, we compared systemic and foliar insecticide treatments for the trap crop borders. We found that using a trap crop system reduced or eliminated the need to spray the main crop area, reducing insecticide use by up to 94% compared with conventional control methods, with no increase in herbivory or beetle numbers. We surveyed the growers who participated in these experiments and found a high level of satisfaction with the effectiveness and simplicity of the system. These results suggest that this method of pest control is both effective and simple enough in its implementation to have high potential for adoption among growers.

In regions with a humid summer climate, the use of water-soluble bait to control apple maggot is often limited by rainfall. We studied increasing the rainfastness of GF-120 fruit fly bait by adding paraffin wax emulsion. First, we verified that adding 10% wax to a mixture containing 16.7% GF-120 did not reduce the mortality of female apple maggot compared with GF-120 without wax. In addition, we determined that fly mortality caused by GF-120 plus wax subjected to simulated rain was similar to that caused by GF-120 without wax not subjected to rain. Other assays showed that higher fly mortality resulted from increasing the proportion of wax from 10 to 15%, and lower mortality resulted from decreasing GF-120 from 16.7 to 10 or 5%. The availability of spinosad on or near droplets of a mixture consisting of 5, 10, or 15% GF-120 and 15% wax was determined before and after the droplets were subjected to three 15-min periods of simulated rain. We found an initial steep decline in dislodgeable spinosad and smaller decreases after subsequent periods of rain. In a small-plot field trial, fruit infestation by apple maggot in plots treated with a mixture consisting of 16.7% GF-120 and 19.2% wax was less than in plots treated with 16.7% GF-120 without wax but not less than in control plots. Overall, we found that adding paraffin wax emulsion to GF-120 increased rainfastness in laboratory bioassays, and specifically that it retained the active ingredient spinosad. However, our field data suggest that optimal rainfastness requires the development of mixtures with >19.2% wax, which may preclude application using standard spray equipment.

The effect of taxa [common Bermuda grass, Cynodon dactylon (L.); centipedegrass, Eremochloa ophiuroides Munro Hack; St. Augustinegrass, Stenotaphrum secundatum [Walt.] Kuntze; and zoysiagrass, Zoysia spp.], density, height, and weed density on abundance of natural enemies, and their potential prey were evaluated in residential turf. Total predatory Heteroptera were most abundant in St. Augustinegrass and zoysiagrass and included Anthocoridae, Lasiochilidae, Geocoridae, and Miridae. Anthocoridae and Lasiochilidae were most common in St. Augustinegrass, and their abundance correlated positively with species of Blissidae and Delphacidae. Chinch bugs were present in all turf taxa, but were 23–47 times more abundant in St. Augustinegrass. Anthocorids/lasiochilids were more numerous on taller grasses, as were Blissidae, Delphacidae, Cicadellidae, and Cercopidae. Geocoridae and Miridae were most common in zoysiagrass and were collected in higher numbers with increasing weed density. However, no predatory Heteroptera were affected by grass density. Other beneficial insects such as staphylinids and parasitic Hymenoptera were captured most often in St. Augustinegrass and zoysiagrass. These differences in abundance could be in response to primary or alternate prey, or reflect the influence of turf microenvironmental characteristics. In this study, Simpson's diversity index for predatory Heteroptera showed the greatest diversity and evenness in centipedegrass, whereas the herbivores and detritivores were most diverse in St. Augustinegrass lawns. These results demonstrate the complex role of plant taxa in structuring arthropod communities in turf. An increased understanding of how turf species and cultivars help shape pest and beneficial arthropod communities will enhance predictive abilities and further pest management objectives.

The efficacy of GF-120 NF Naturalyte Fruit Fly Bait in combination with field sanitation was assessed as a control for female oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in papaya (Carica papaya L.) orchards in Hawaii. Three different bait spray regimes were evaluated: every row (high use of the bait), every fifth row (moderate use), and every 10th row (low use). Orchard plots in which no bait was applied served as controls. For five of the seven biweekly periods that followed the first bait spray, trapping data revealed significantly fewer female B. dorsalis captured in plots subject to high and moderate bait use than in control plots. Differences in incidence of infestation among treatments were detected only by the third (12 wk after first spray) fruit sampling with significantly fewer infested one-fourth to bonehead ripe papaya fruit in plots subject to high and moderate bait use than in control plots. Parasitism rates by Fopius arisanus (Sonan) (Hymenoptera: Braconidae) were not negatively affected by bait application. Results indicate that foliar applications of GF-120 NF Naturalyte Fruit Fly Bait either to all rows (every other tree), or to every fifth row (every tree) in combination with good sanitation can effectively reduce infestation by B. dorsalis in papaya orchards in Hawaii.

Halyomorpha halys is an introduced stink bug species from Asia that is spreading throughout the Mid-Atlantic United States. It is native to South Korea, Japan, and eastern China, where it is an occasional pest of tree fruit, including apple and pear. Cage experiments with adults placed on apple and peach during critical plant growth stages demonstrate that it can cause damage to developing fruit during mid- and late season growth periods and that feeding occurs on all regions of the fruit. Feeding that occurred during pit hardening/mid-season and final swell periods were apparent as damage at harvest, whereas feeding at shuck split/petal fall in peaches and apples caused fruit abscission. Tree fruit at two commercial farms were sampled weekly in 2006–2007 to determine H. halys seasonality. Low densities of nymphs in apple suggest that it is an unsuitable developmental host. Both nymphs and adults were found on pear fruits with peak populations occurring in early July and mid-August, the time when pit hardening/mid-season and swell period damage occurs. At both farms, stink bug damage was greater than 25% damaged fruit per tree. We attribute this to H. halys because population densities were significantly higher than native pentatomids at both locations in both beat samples and blacklight trap captures. The data presented here documents the potential for H. halys to cause damage in orchards throughout the Mid-Atlantic United States and shows the need for development of appropriate control strategies.

The hypothesis that herbivory by Diaprepes root weevil larvae reduces leaf gas exchange and biomass was tested on buttonwood (Conocarpus erectus L.), Surinam cherry (Eugenia uniflora L.), mahogany (Sivietenia mahagoni Jacq.), and pond apple (Annona glabra L). For Surinam cherry, net CO₂ assimilation, transpiration, and stomatal conductance, but not internal CO₂ concentration (collectively referred to as leaf gas exchange values), were 7–32% higher in noninfested than infested plants. For buttonwood, all four gas exchange values were 10–54% higher for noninfested than infested plants 3 h after infestation with large, seventh-instar larvae. However, by 4 wk after this infestation, net CO₂ assimilation, transpiration, and stomatal conductance, but not internal CO₂ concentration, were 11–37% higher for infested than for noninfested plants. For mahogany and pond apple, there were few or no significant differences in leaf gas exchange values between infested and noninfested plants. For all species, mean shoot and root fresh and dry weights were higher for noninfested than infested plants, with the differences most significant for buttonwood (37–85% higher), followed by Surinam cherry (37–143% higher), mahogany (49–84% higher), and pond apple (24–46% higher), which had no significant differences. There were significant differences among plant species in mean head capsule widths, thus larval instars, of larvae recovered from soil with the largest larvae from Surinam cherry (2.59 ± 0.19 mm) and the smallest from mahogany (2.29 ± 0.06 mm). Based on differences in leaf gas exchange and plant biomass between infested and noninfested plants of the four species tested, buttonwood and Surinam cherry are the most vulnerable to feeding by Diaprepes larvae followed by mahogany then pond apple.

Predatory potential and performance of the predaceous heteropterans, Geocoris punctipes (Say), G. uliginosus (Say) (Geocoridae), and Onus insidiosus (Say) (Anthocoridae), were evaluated using fall army worm, Spodoptera frugiperda (J. E. Smith), as prey on different turfgrass taxa (resistant zoysiagrasses, ‘Cavalier’ and ‘Palisades’; moderately resistant Bermuda grass, ‘TifSport’; and susceptible seashore paspalum, ‘Sea Isle 1’) through laboratory and field studies. When background mortality was taken into account, in small arena trials in the laboratory, the greatest mortality by predators occurred on TifSport. The predator impact on TifSport by O. insidiosus was 92.6% above the mortality in the no-predator treatment on that grass. Predator induced mortality was rarely significant on the highly resistant zoysiagrass cultivar Cavalier because mortality, even in the absence of predators, was so high. Survival of larvae on TifSport Bermuda grass was significantly reduced by the addition of just two O. insidiosus per pot in laboratory pot trials. An increase in predator density to 4, 6, 8, or 10 further suppressed larval survival. O. insidiosus reduced larval survival on Sea Isle 1 at all densities. On Sea Isle 1, a density of two O. insidiosus resulted in >50% reduction in live fall armyworms compared with the no predator treatment in laboratory trials. However, addition of O. insidiosus did not significantly reduce survival of fall armyworm larvae on this cultivar in the field in the presence of alternative prey and predators. O. insidiosus densities of six or higher per 181.4 cm² did significantly reduce larval survival on TifSport Bermuda grass by as much as 80% during a 5-d trial period in the field. Predator-induced mortality among all trials was most consistent on a grass of intermediate resistance, TifSport Bermuda grass.

A fruit fly bait to attract and kill adult fruit flies, GF-120, was tested in cages to determine effects of pretreatment diet and bait aging before use on cumulative mortality rates of Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae). Protein-starved and protein-fed, 9-d-old flies both experienced varying overall cumulative mortality at 4, 8, 24, and 48 h. Pretreatment diet had no significant effect on mortality. Overall mortality rates were below 10% for 4 h, 39–43% at 8 h, but mortality in all treatments increased to 89–93% by 24 h, and 99% by 48 h. In a second experiment, GF-120 baits were either freshly prepared or aged for 24 h. Subtreatments consisted of protein-fed and protein-starved flies. The 24-h-aged bait killed significantly more flies at 4 and 8 h than the freshly prepared bait. Protein-starved flies had significantly higher mortality at 4 h and marginally higher mortality at 8 h than protein-fed flies. At 24 and 48 h, there were no significant differences among treatments, and overall morality rose to 99–100% by 48 h. These results may explain differences noted in previous publications in which fruit fly mortality to GF-120 was reported as unusually low as well as reports of bait ineffectiveness for protein-fed flies. The overall impact of any initial repellency of GF-120 seems negligible as judged by overall cumulative mortality at later evaluation times.

The current study evaluated the effect of different classes of insecticides against bagworms (Lepidoptera: Psychidae) on arborvitae by using a laboratory bioassay that allowed us to simultaneously evaluate the feeding rate, growth, and mortality of larvae. Soil application of the systemic insecticides dinotefuran and (to a lesser extent) chlothianidin increased larval mortality and reduced the feeding rate and growth of larvae, up to 50 d posttreatment. The effectiveness of systemic insecticides against bagworms makes them well suited to control bagworms on tall trees heavily infested in the upper canopy. Chlorantranilipole and indoxacarb were as effective in controlling bagworms as other contact insecticides commercially available (spinosad and bifenthrin). Chlorantraniliprole had a residual effect 10 d posttreatment and may therefore provide an effective tool to protect the foliage of arborvitae against bagworms over a sustained period.

The Argentine ant is well known for its affinity for honeydew and is often associated with hemipteran outbreaks in agricultural and urban environments. It has been suggested that Argentine ants may be controlled by restricting access to honeydew, thereby forcing the ants to move or by encouraging increased liquid toxicant intake. We tested this possible control strategy by restricting Argentine ant access to the honeydew-producing terrapin scale within the canopy of red maple trees and monitoring ant numbers with pitfall traps and nest counts in the mulch around the tree base. Argentine ant nest numbers fell dramatically in the mulch around ant-excluded trees; however, there was no reduction in Argentine ant numbers caught in pitfalls around trees with or without canopy access. We added 0.5% boric acid bait stations at the base of the red maples and monitored bait consumption. Pitfall and nest counts were not affected by the addition of boric acid, although bait consumption was lower around ant-excluded trees, suggesting that restricting access to honeydew-producing Hemiptera did not enhance bait performance. We attribute this result to the increased distance Argentine ant workers had to trail from nest to bait station when not tending nearby terrapin scale. We suggest an alternative management strategy concentrating direct insecticidal control of Argentine ants around a few host plants infested with honeydew-producing Hemiptera by controlling Hemiptera in nearby host plants.

Field tests of four different bait supplements were conducted in City Park, New Orleans, LA. The four bait supplements tested included two different formulations of decayed material, a sports drink, and the combination of an application of an aqueous solution of Summon Preferred Food Source disks with the disk itself. Although all the bait supplements in this study resulted in a slightly greater number of treated stations discovered compared with control stations, only the application of the aqueous solution combined with the disk caused a significant increase in the number of stations discovered by termites. This treatment resulted in a significantly greater rate of discovery of treated stations versus control stations after only 14 d in the field. Termites were able to discover six times as many treated as control stations after 14 d, 9 times as many after 28 d, and 12 times as many after 42 d. These findings provide evidence that the diffusion of an aqueous solution into the soil underneath monitoring stations significantly decreased the length of time required for termites to infest stations.

Bed bugs, Cimex lectularius L., hide in cracks and crevices in furniture and are difficult to control. The bed bug thermal death kinetics were examined to develop a heat treatment method to eliminate bed bug infestations in room contents. High temperatures caused temporary immobilization (knockdown) of bed bugs even with exposures that did not have lethal effects. Exposure of bed bug adults to 39°C for 240 min caused no mortality; however, as temperatures increased from 41 to 49°C, exposure times that caused 100% mortality decreased. The temperature difference to provide a 10-fold change in the mortality was estimated at 4°C, and the estimated activation energy (E_A) was between 484 and 488.3 kJ/mol. This demonstrates that bed bugs are not more resistant or susceptible to changes in temperature than other tested insects and that the temperatures needed to kill bed bugs are relatively low. In room treatment tests, heat treatment times varied from 2 to 7 h with complete mortality of exposed bed bugs within the treatment envelope created by surrounding the treated furniture with polystyrene sheathing boards. Containment and circulation of heat around the treated material were crucial factors in an efficient heat treatment for bed bug control. The room floor material greatly affected containment of the heat. The tested method for limited heat treatment of furniture and other room contents required equipment costing less than US$400 and provided opportunity for residual pesticide application around the room with minimal disruption in use of treated room.

Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), is a cosmopolitan and destructive pest in rice fields of the world. This pest was reported in 1973 in Iran, and it has since spread widely in rice, Oryza sativa L., fields throughout the country. In this study, we tried to evaluate comparative toxicity of diazinon in five colonies of C. suppressalis, collected from Babol (Ba), Amol (Am) of Mazandaran Province and Rasht (Ra), Sheikhmahale (Sh), and Gourabzarmikh (Go) of Guilan Province, northern Iran. The LD₅₀ values were compared. We also evaluated the general esterases, alkaline phosphatase (ALP), glutathione transferase (GST), and acetylcholinesterase (AChE) activities from the five populations. The LD₅₀ values of Ra, Ba, Am, and Sh (12.64, 11.4, 7.17, and 3.71 µg/ mg larva-1) were 13.67-, 12.33-, 7.75-, and 4.02-fold higher than Go population (0.924 µg/mg larva-1). Using α-naphthyl acetate as substrate, the general esterase activities in Ra, Ba, Am, and Sh colonies were, respectively, 1.81-, 1.68-, 1.75-, and 1.35-fold more than those in Go population. When β-naphthyl acetate was used as the substrate, activity ratio was measured 1.98-, 2.58-, 1.25-, and 1.24-fold compared with the Go population. Glutathione transferase activities in Ra, Ba, Am, and Sh populations were 1.27-, 1.68-, 0.98-, and 1.7-fold more than those in Go, when 1-chloro-2,4-dinitrobenzene was used as the substrate. When 1,2-dichloro-4-nitro-benzene was used as the substrate, activity ratio was measured 1.14-, 1.42-, 0.56-, and 0.95-fold compared with Go population. The ALP activity demonstrated a significant difference among these populations and in Ra, Ba, Am, and Sh larvae were 3.54-, 4.62-, 3.84-, and 2.18-fold more than Go. The AChE inhibition or I50 value was 0.19, 0.22, 0.31, 0.19, and 0.26 mM in Ra, Ba, Am, Sh and Go populations, respectively. However, the results showed no significant differences in studied colonies. These biochemical characterizations of general esterases ALP, GST, and AChE were consistent with diazinon bioassay in the five populations. It is inferred from increased esterase, alkaline phosphatase and glutathione transferase, activities that might play an important role in the increasing resistance in C. suppressalis to diazinon among these five populations.

Crude hexane and water extracts of Catharanthus roseus Linn. (Syn: Vinca rosea) (Apocyanaceae) stem, leaf, and seed exhibited pesticidal activity against Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). The extracts differed significantly in their efficacy, with the crude hexane extract of whole seed being the most effective in curtailing pupal survivorship to 18% followed by the hexane extracts of leaf (21%) and stem (24%). Average pupal weight (68.2 mg) and length (1.5 cm) in the whole seed treatment were drastically reduced, compared with the controls (415.2 mg and 2.72 cm), subsequently reducing adult emergence to 15.7%. SiO₂ column purification yielded eight fractions of which fraction 1 exhibited 90% larval mortality, with severe reduction of the larvae weight (12.7 mg) and length (1.5 cm). Gas chromatographic-mass spectrometric analysis of fraction 1 suggested the presence of 16 compounds, among which oleic, linoleic, palmitic, and margaric acids were detected as major constituents. Presence of the alkane hydrocarbons triacontane, tetracosane, and heptacosane also was noted.

In 2009, pyrethroid resistance was confirmed for seven “annual bluegrass weevil” Listronotus maculicollis Kirby (Coleoptera: Curculionidae) adult populations from southern New England. The mechanisms responsible for conferring this resistance were unknown. In this study, topical application bioassays with bifenthrin and bifenthrin combined with synergists affecting three detoxification systems were conducted on four field-collected adult populations of L. maculicollis from Connecticut to determined whether cytochrome P450 monooxgenases (P450s), glutathione S-trans-ferases (GSTs), and/or carboxyl-esterases (COEs) mediated metabolic detoxification. Because a susceptible L. maculicollis laboratory strain does not exist, the most susceptible field-collected population (New Haven) provided a baseline against which all other populations were compared. In the population with the lowest resistance (Norwich), only detoxification by P450s was significant. Detoxification in the population with the second highest level of resistance (Stamford) involved both P450s and GSTs. Detoxification in the population with the highest level of resistance (Hartford) involved P450s, GSTs, and COEs. This study suggests that enzyme-mediated metabolic detoxification plays an important role in annual bluegrass weevil pyrethroid resistance.

Euschistus heros (F.) (Heteroptera: Pentatomidae) is the most prevalent stink bug pest in Brazil, and populations can be difficult to manage using organophosphates or endosulfan. Because E. heros is difficult to rear in the laboratory, no baseline insecticide susceptibility data have been published. Therefore, we conducted dose-mortality studies using field-collected insects, and, using the results from the dose-mortality studies, we surveyed susceptibility to acephate, methamidophos, and endosulfan in populations from southern and central Brazil. In addition, esterase activity was evaluated among populations as these enzymes have been related to organophosphate resistance. Finally, newer chemistries were evaluated for E. heros population management in small-plot field studies. In the dose-mortality bioassays, variation in susceptibility to methamidophos and endosulfan among populations was significant, but the variation in susceptibility to acephate was not. The population from Londrina (at the Embrapa Soybean Research Station, northern Parana state) was among the most susceptible, whereas the population from Pedrinhas Paulista (southwestern Sao Paulo state) was among the least susceptible. Significant variation among populations was observed in esterase activity with the population from Pedrinhas Paulista having the highest esterase levels and the population from Londrina having among the lowest levels. To survey populations, we used the dose-mortality data for the Londrina population (because it was, consistently, one of the most susceptible populations) to estimate the insecticide concentration that killed 99% of the population (LC₉₉). The corresponding doses were 5.9 µg (AI) of acephate adult^-1, 0.7 µg (AI) methamidophos adult^-1, and 1,600 µg (AI) endosulfan adult^-1. The survey data confirmed the data from the dose-mortality bioassays in that the population from Pedrinhas Paulista was identified as one of the least susceptible and the population from Londrina was one of the most susceptible. The field tests confirmed that older chemistries provided minimal control (<50% control), whereas the products containing mixtures of pyrethroids and neonicotinoids provided better control (>60%).

Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is an important lepidopteran pest of cotton, Gossypium hirsutum L., in Asia. Transgenic cotton expressing the cry1Ac gene from Bacillus thuringiensis (Bt) has been widely planted for control of this pest. For managing the potential risk from resistance evolution in this pest, a new transgenic Bt cotton containing cry1Ac and cry2Ab genes (gene pyramided strategy) was designed as a successor of cry1Ac cotton. This article reports on levels of Cry2Ab tolerance in H. armigera populations from Cry1Ac cotton planting region in China based on bioassays of F₁ and F₂ offspring of isofemale lines. In total, 572 isofemale families of H. armigera from Xiajin County of Shandong Province (an intensive Bt cotton-planting area) and 124 families from Anci County of Hebei Province [a multiple-crop system, including corn (Zea mays L.), soybean (Gycine max (L.) Merr., peanut (Arachis spp.), and Bt cotton] were screened with both Cry1Ac- and Cry2Ab-containing diets in 2008. The bioassays results indicated that relative average development rates (RADR) of F₁ full-sib families from field-collected female moths on Cry1Ac- and Cry2Ab-containing diet were positively correlated. The same correlation was found in the F₂ generation, indicating cross-tolerance between Cry1Ac and Cry2Ab in field populations of H. armigera in Yellow River cotton-farming region of China. This cross-tolerance must be considered in evaluating the utility of pyramiding Bt genes in cotton for delaying evolution of resistance.

Widespread planting of crops genetically engineered to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) imposes selection on many key agricultural pests to evolve resistance to Bt. Fitness costs can slow the evolution of Bt resistance. We examined effects of entomopathogenic nematodes on fitness costs of Bt resistance in the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), a major pest of cotton, Gossypium hirsutum L., in the southwestern United States that is currently controlled by transgenic cotton that produces Bt toxin Cry1Ac. We tested whether the entomopathogenic nematodes Steinernema riobrave Cabanillas, Poinar, and Raulston (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae) affected fitness costs of resistance to Cry1Ac in two laboratory-selected hybrid strains of pink bollworm reared on non-Bt cotton bolls. The nematode S. riobrave imposed a recessive fitness cost for one strain, and H. bacteriophora imposed a fitness cost affecting heterozygous resistant individuals for the other strain. Activity of phenoloxidase, an important component of insects' immune response, did not differ between Bt-resistant and Bt-susceptible families. This suggests phenoloxidase does not affect susceptibility to entomopathogenic nematodes in Bt-resistant pink bollworm. Additionally, phenoloxidase activity does not contribute to Bt resistance, as has been found in some species. We conclude that other mechanisms cause higher nematode-imposed mortality for pink bollworm with Bt resistance genes. Incorporation of nematode-imposed fitness costs into a spatially explicit simulation model suggests that entomopathogenic nematodes in non-Bt refuges could delay resistance by pink bollworm to Bt cotton.

Maintenance of genetic diversity among breeding lines is important in selective breeding and stock management. The Russian Honey Bee Breeding Program has strived to maintain high levels of heterozygosity among its breeding lines since its inception in 1997. After numerous rounds of selection for resistance to tracheal and varroa mites and improved honey production, 18 lines were selected as the core of the program. These lines were grouped into three breeding blocks that were crossbred to improve overall heterozygosity levels of the population. Microsatellite DNA data demonstrated that the program has been successful. Heterozygosity and allelic richness values are high and there are no indications of inbreeding among the three blocks. There were significant levels of genetic structure measured among the three blocks. Block C was genetically distinct from both blocks A and B (FST = 0.0238), whereas blocks A and B did not differ from each other (FST = 0.0074). The same pattern was seen for genic (based on numbers of alleles) differentiation. Genetic distance, as measured by chord distance, indicates that all of the 18 lines are equally distant, with minimal clustering. The data indicate that the overall design of the breeding program has been successful in maintaining high levels of diversity and avoiding problems associated with inbreeding.

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), ranks as one of the world's most destructive agricultural pests. This pest is also widespread and highly invasive; thus, it is a high priority for pest detection and quarantine programs. Although Mediterranean fruit fly adult and third-instar larvae can usually be identified and distinguished from other species by morphological keys, it is often difficult or impossible to identify or distinguish this species from other tephritids by using material from other stages of development. In such situations, use of a molecular technique known as loop-mediated isothermal amplification (LAMP) would be valuable as a rapid and robust alternative species diagnostic tool. This method uses isothermal conditions and requires only relatively inexpensive equipment. In this study we have developed a simple and rapid procedure that combines a Chelex-based DNA extraction procedure with LAMP to rapidly detect the presence of Mediterranean fruit fly DNA and discriminate it from other species, by using material from different stages of development. Amounts of DNA as little as that recovered from a single egg were shown to be adequate for the analysis, and LAMP itself required only 45 min to complete.

Hemlock (Tsuga) species and hybrids were evaluated for resistance to the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae). The adelgid was accidentally introduced from Asia to the eastern United States, where it is causing widespread mortality of the native hemlocks, Tsuga canadensis (L.) Carrière and Tsuga caroliniana Engelm. These two native species plus the Asian species Tsuga chinensis (Franch.) E. Pritz and T. dumosa (D.Don) Eichler and Tsuga sieboldii Carrière, and the hybrids T. chinensis × T. caroliniana and T. chinensis × T. sieboldii, were artificially infested with the crawler stage of A. tsugae in the early spring 2006 and 2007. After 8 or 9 wk—when the spring (progrediens) generation would be mature—counts were made of the adelgid. In both years, the density of A. tsugae was highest on T. canadensis, T. caroliniana, and T. sieboldii; lowest on T. chinensis; and intermediate on the hybrids. On T. chinensis and the T. chinensis hybrids, fewer adelgids settled, fewer of the settled adelgids survived, and the surviving adelgids grew slower. Thus, the nature of the host resistance is both nonpreference (antixenosis) and adverse effects on biology (antibiosis). Tree growth (height) was associated with resistance, but no association was found between time of budbreak and resistance that was independent of the taxa. Many of the hybrids grow well, have attractive form, and are promising as resistant landscape alternatives for the native hemlocks.

The Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), devastates wheat and barley production on all continents except Australia. Although D. noxia-resistant cultivars exist, virulent D. noxia populations exist in Asia, North America, and South America that have the ability to overcome resistance. In this study, synthetic hexaploid wheat genotypes created at the International Maize and Wheat Improvement Center (CIMMYT) were evaluated and characterized for resistance to North American biotype 2 (RWA2). Fewer RWA2 were produced on several genotypes, and D. noxia-induced leaf rolling and chlorosis were reduced on these genotypes as well. Aphid numbers were positively correlated with chlorosis and with leaf rolling. However, some genotypes were highly resistant to leaf rolling and chlorosis while supporting large RWA2 populations. There were negative correlations between leaf chlorosis and leaf dry weight (r = -0.267, df = 106, P = 0.006) and between aphid numbers and leaf dry weight (r = -0.297, df = 105, P = 0.002). These results indicate that chlorosis and aphid number individually explain at least 27% of the changes observed in leaf dry weights. Interestingly, there was no correlation between leaf rolling and leaf dry weight. The RWA2-resistant lines identified, which are also resistant to D. noxia populations in Mexico and to greenbug (Schizaphis graminum Rondani) biotype G, are strong candidates for use in improving the genetic diversity in bread wheat for resistance to different biotypes of both S. graminum and D. noxia.

The black pecan aphid, Melanocallis caryaefoliae (Davis) (Hemiptera: Aphididae), is a foliar feeder of pecan, Carya illinoinensis (Wangenh.) K. Koch (Juglandaceae). The pest causes chlorosis of leaflet lamina, physiological damage to foliage and trees, and commonly limits the profitability of commercial pecan orchard enterprises. However, key aspects of this host-pest interaction are poorly understood. We report here the effects of M. caryaefoliae feeding on the foliar activity of oxidative (i.e., catalase, lipoxygenase [LOX]-1 and 3, and peroxidase) andhydrolytic (i.e., esterase) enzymes in relation to the degree of aphid resistance among pecan varieties. The 2-yr study showed that M. caryaefoliae-infested foliage exhibited elevated peroxidase activity only in susceptible (‘Desirable’, ‘Sumner’, and ‘Schley’), but not in resistant (‘Cape Fear’, ‘Gloria Grande’, and ‘Money Maker’) genotypes. Susceptible genotypes also exhibited more severe leaf chlorosis in response to M. caryaefoliae feeding than the resistant genotypes; however, the aphid feeding did not influence catalase or esterase activity in all varieties, except the increase of esterase activity in Desirable and Gloria Grande. Melanocallis caryaefoliae feeding also influences activity of two lipoxygenase isozymes, with LOX3 being more frequently induced than LOX1. Foliar LOX3 activity was more frequently induced by M. caryaefoliae feeding in the moderately resistant ‘Oconee’ and highly resistant Money Maker and Cape Fear than in the susceptible genotypes. Therefore, the elevation of peroxidase is likely to be associated with aphid susceptibility and contributed to the severe leaf chlorosis, whereas the increase of LOX3 activity might be associated with aphid resistance in pecan. These findings contribute to our understanding of the etiology of M. caryaefoliae-elicited leaf chlorosis on pecan foliage. Such information may also be used to develop enzyme markers for identifying black pecan aphid resistance and/or susceptibility in pecan germplasm.

The Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), is the most destructive insect pest of potato, Solanum tuberosum (L.), in North America. Avidin sequesters available biotin, thereby causing abnormal growth and development of insects. We expressed avidin in two potato lines: MSE149-5Y, a susceptible potato line, and ND5873-15, a line with S. chacoense-derived insect resistance. A preliminary study was conducted to determine the bioactivity of the transgene in each background. A single transgenic line was selected in each background for further studies. Detached leaf bioassays were performed on transgenic and nontransgenic clones of the susceptible and S. chacoense lines by using first-stage Colorado potato beetle larvae. Consumption, survival, and survivor growth were measured after 5 d. Larvae consumed significantly less on the two avidin-expressing lines compared with the nontransgenic lines. Survival was also significantly less for larvae feeding on transgenic avidin lines compared with the nontransgenic lines. The mass of survivors was significantly reduced on two transgenic avidin lines compared with the nontransgenic lines. Further studies examined the development from first-stage larvae to adulthood on greenhouse-grown whole plants in a no-choice setting for larvae fed on the four potato lines. Development from first stage to pupation was significantly prolonged for larvae fed on the avidin line compared with larvae fed on the susceptible line. Significantly fewer larvae fed on transgenic avidin plants, avidin or avidin S. chacoense-derived line survived to adulthood compared with survival on nontransgenic plants, susceptible or S. chacoense-derived line. Avidin-based resistance may be useful in managing Colorado potato beetle populations in commercial planting by reducing the population size.

A 7-yr field study evaluated 61 oilseed sunflower, Helianthus annuus L, accessions and 31 interspecific crosses for resistance to attack by naturally occurring populations of three stem-infesting pests, the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae); a longhorned beetle, Dectes texanus LeConte (Coleoptera: Cerambycidae); and a root boring moth, Pelochrista womonana (Kearfott) (Lepidoptera: Tortricidae), at two locations in the central Great Plains. Germplasm with potential sources of resistance to attack from all three stem-infesting species were revealed. Accessions PI 650558, PI 386230, and PI 431516 were consistent in averaging low densities of stem weevil larvae per stalk among lines tested, and PI 497939 exceeded 25 weevil larvae per stalk in only 1 yr of 5 yr of trials. Several interspecific crosses also had consistently low densities of C. adspersus larvae per stalk. Populations of both D. texanus and P. womonana were variable over years, but differences among the lines tested were evident in many trials, revealing potential for developing resistant germplasm. Four accessions (PI 386230, PI 431542, PI 650497, and PI 650558) had low larval densities of C. adspersus and P. womonana in addition to reduced percentage infestation by D. texanus. Results showed potential for developing resistant genotypes for these pests. The prospect of adding host plant resistance as an integrated pest management (IPM) tactic would provide another tool for reducing economic losses from stem-infesting insect pests of sunflower in the central Great Plains.

In this study, wheat, Triticum aestivum L. (em Thell), genotypes containing the Dnx, Dn7, Dn6, and Dn4 genes for resistance to the Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), along with Dn0, a susceptible control, were assessed to determine the categories of D. noxia biotype 2 (RWA2) resistance in each genotype and RWA2 feeding behaviors on Dnx and Dn0 plants by using the electronic penetration graph technique. At 14 d postinfestation, Dn0 plants exhibited intense chlorosis and leaf rolling, and all test genotypes expressed some degree of chlorosis and leaf rolling, except Dn7, which was not damaged. Both Dn7 and Dnx expressed antibiosis effects, significantly reducing the numbers of aphids on plants and the intrinsic rate of aphid increase. Dn6 plants seemed to contain tolerance, exhibiting tolerance index measurements for leaf and root dry weight and plant height that were significantly lower than those of the susceptible Dn0 plants. Principal component analyses indicated that antibiosis and leaf rolling data explained 80% of the variance among genotypes. Electronic penetration graph analysis demonstrated contrasting results between RWA1 and RWA2 phloem sieve element phase feeding events, but results indicated that Dnx resistance factors are present in the sieve element cells or phloem sap. Plants containing Dnx exhibit antibiosis resistance to D. noxia RWA2 similar to that in plants containing the Secale cereale L. (rye)-based Dn7 gene without the negative baking quality traits associated with Dn7.

Quantitative enzyme-linked immunosorbent assays were used to characterize the geographical (locations) and temporal (through 6 wk) expression of Cry1Ac, from Bacillus thuringiensis variety kurstaki, and Cry1F, from B. thuringiensis variety aizawai, in transgenic cotton, Gossypium hirsutum L., plant structures. Terminal leaves, squares (flower buds), flowers, bolls (fruit), and mature leaves located five and eight nodes below the terminal apex were sampled during weeks 2, 4, and 6 after the initiation of anthesis. The effect of location (environment) significantly influenced protein expression levels, although similar trends were observed across locations. Cry1F was expressed at levels greater (1.1-29.0-fold) than that for Cry1Ac in all structures with exception to flowers. In contrast, the level of Cry1Ac in flowers was generally greater than Cry1F. Within each sampling period, concentrations of Cry1F in mature leaves (five and eight node) were greater than that for other structures. Expression was also greater for older, eight-node mature leaves than younger, five-node mature leaves. Cry1Ac expression in bolls was lowest compared with terminal leaves, squares, flowers, and mature leaves, which expressed at similar concentrations. Cry1F expression increased through time for mature leaves and terminal leaves; whereas, a decline in Cry1Ac protein concentration was observed for terminal leaves and bolls. The data presented here provides a means to understand observed levels of efficacy (patterns of insect damage) by comparing the spatial and temporal dynamics of expression for Cry1Ac and Cry1F in PhytoGen 440W transgenic cotton.

Both nymphal and adult stages of several species of spittlebugs (Hemiptera: Cercopidae) are key economic pests of brachiariagrasses (Brachiaria spp.) in tropical America. Progress has been made in the characterization and development of antibiosis resistance to nymphs in brachiariagrasses. Essentially no attention has been given to screening germplasm for resistance to adults. To support current breeding programs, a series of experiments was conducted to develop a methodology to screen for adult damage and to study categories of resistance to adult feeding damage. Six host brachiariagrass genotypes were used: two susceptible checks (CIAT 0606 and CIAT 0654) and four nymph-resistant genotypes (CIAT 6294, CIAT 36062, CIAT 36087, and SX01NO/0102). Test insects were Aeneolamia varia (F.) and Zulia carbonaria (Lallemand). None of the nymph-resistant genotypes was antibiotic to adults. All four nymph-resistant genotypes showed tolerance to A. varia and Z. carbonaria feeding damage. The levels of tolerance to adults of Z. carbonaria, a larger, more aggressive species, were lower. Of the four nymph-resistant genotypes, only CIAT 6294 and CIAT 36087 showed some tolerance to Z. carbonaria expressed as lower leaf damage scores, less chlorophyll loss, and lower functional plant loss indices. The fact that a genotype like SX01NO/0102, which is highly antibiotic to nymphs, is susceptible to adult damage suggests that mechanisms of resistance to the two spittlebug life stages may be independent. Results of these studies suggest a need to incorporate routine screening for tolerance to adult feeding damage as an additional selection criterion in the breeding scheme.

The western corn rootworm, Diabrotica virgifera virgifera (LeConte), is a major pest of maize, Zea mays L., in the United States and Europe, and it is likely to increase in importance as a trend toward increased nonrotated maize favors larger rootworm populations. Options for rootworm management in nonrotated maize in Europe and in nontransgenic “refuge” areas in countries that permit transgenic maize are limited to insecticides. Development of additional options for growers would be helpful. Screening maize germplasm (e.g., landraces, populations, inbreds) for native resistance to western corn rootworm is labor-intensive and is usually conducted on unfinished germplasm and not on hybrid materials. However, we have recently observed that topcrossed (hybrid) materials tend to have reduced western corn rootworm damage. To formally test whether rootworm damage to inbreds and associated hybrids were correlated, we evaluated 25 diverse inbred lines and their B73 hybrids for western corn rootworm damage in seven environments. Overall, hybrids had significantly less damage than inbreds, but unfortunately, the correlation between inbreds and hybrids was not significant. These findings have important implications regarding screening germplasm for western corn rootworm resistance, namely, that inbred materials and perhaps populations should be topcrossed to form hybrid materials before screening for western corn rootworm damage to ensure that valuable sources of resistance to western corn rootworm are not missed during the screening process.

Binomial sequential sampling plans were developed to forecast weevil Listronotus maculicollis Kirby (Coleoptera: Curculionidae), larval damage to golf course turfgrass and aid in the development of integrated pest management programs for the weevil. Populations of emerging overwintered adults were sampled over a 2-yr period to determine the relationship between adult counts, larval density, and turfgrass damage. Larval density and composition of preferred host plants (Poa annua L.) significantly affected the expression of turfgrass damage. Multiple regression indicates that damage may occur in moderately mixed P. annua stands with as few as 10 larvae per 0.09 m2. However, >150 larvae were required before damage became apparent in pure Agrostis stolonifera L. plots. Adult counts during peaks in emergence as well as cumulative counts across the emergence period were significantly correlated to future densities of larvae. Eight binomial sequential sampling plans based on two tally thresholds for classifying infestation (T = 1 and two adults) and four adult density thresholds (0.5, 0.85, 1.15, and 1.35 per 3.34 m²) were developed to forecast the likelihood of turfgrass damage by using adult counts during peak emergence. Resampling for validation of sample plans software was used to validate sampling plans with field-collected data sets. All sampling plans were found to deliver accurate classifications (correct decisions were made between 84.4 and 96.8%) in a practical timeframe (average sampling cost <22.7 min).

The combined action of two lepidoteran pests, Plutella xylostella L. (Plutellidae) and Pieris rapae L. (Pieridae), causes significant yield losses in cabbage (Brassica oleracea variety capitata) crops in the Democratic People's Republic of Korea. Integrated pest management (IPM) strategies for these cropping systems are in their infancy, and sampling plans have not yet been developed. We used statistical resampling to assess the performance of fixed sample size plans (ranging from 10 to 50 plants). First, the precision (D = SE/mean) of the plans in estimating the population mean was assessed. There was substantial variation in achieved D for all sample sizes, and sample sizes of at least 20 and 45 plants were required to achieve the acceptable precision level of D ≤ 0.3 at least 50 and 75% of the time, respectively. Second, the performance of the plans in classifying the population density relative to an economic threshold (ET) was assessed. To account for the different damage potentials of the two species the ETs were defined in terms of standard insects (SIs), where 1 SI = 1 P. rapae = 5 P. xylostella larvae. The plans were implemented using different economic thresholds (ETs) for the three growth stages of the crop: precupping (1 SI/plant), cupping (0.5 SI/plant), and heading (4 SI/plant). Improvement in the classification certainty with increasing sample sizes could be seen through the increasing steepness of operating characteristic curves. Rather than prescribe a particular plan, we suggest that the results of these analyses be used to inform practitioners of the relative merits of the different sample sizes.

Previous research showed that the most precise estimates of stink bug damage in developing cotton bolls are obtained by collecting soft quarter-sized bolls and dissecting them for signs of internal feeding damage, such as internal boll wall warts and/or stained lint. However, this method requires considerable time and effort; therefore, scouts and growers are unwilling to invest adequate resources to make sound pest management decisions. Here, the authors evaluated enumeration of external feeding lesions on groups of 10, 15, 20, or 25 bolls per sample as an alternative sampling procedure. Results relate the similarity of external boll feeding lesions to internal damage as a function of boll sample size and external lesion tally. Inverse prediction confidence intervals (CIs) were also calculated to predict internal boll damage on a new sample based only on external feeding lesions. Results show that linear regression model fit increased when examining at least 20 bolls per sample, and only one external lesion per boll provided as good of model fit as using a minimum of two, three, or four lesions per boll. Inverse prediction CIs suggested that more than one sample (20 bolls per sample) will be required to make external lesions an acceptable method for making reasonably accurate management decisions. F-test lack of fit and significant regression models suggest that examination of external lesions is a promising a method for estimating stink bug damage in cotton.

The insecticidal efficacy of abamectin against adults of Rhyzopertha dominica (F.), Sitophilus oryzae (L.), and Tribolium confusum Jacquelin du Val was assessed under laboratory conditions. The efficacy of abamectin was assessed on two commodities (wheat, Triticum aestivum L. and maize, Zea mays L.) and two temperatures (25 and 31°C). The dose rates used were 0.01, 0.1, 0.5, and 1 ppm. Mortality of the exposed adults in the treated grains was measured after 7, 14 and 21 d (=days), whereas progeny production was assessed 60 d later. Increase of dose rate, exposure interval, and temperature enhanced the efficacy of abamectin. Noticeable mortality was noted for all species after 21 d of exposure, although for S. oryzae, mortality was very high even at 7 d. For dose rates higher than 0.5 ppm, the efficacy of abamectin was higher in maize than in wheat against all species tested. Finally, progeny production was measured for all three species on commodities treated with 0.01 and 0.1 ppm of abamectin.

We studied the effects of temperature and relative humidity on population growth and development of the psocid Liposcelis brunnea Motschulsky. L. brunnea did not survive at 43% RH, but populations increased from 22.5 to 32.5°C and 55–75% RH. Interestingly, we found population growth was higher at 63% RH than at 75% RH, and the greatest population growth was recorded at 32.5°C and 63% RH. At 35°C, L. brunnea nymphal survivorship was 33%, and populations declined or barely grew. L. brunnea males have two to four nymphal instars, and the percentages of males with two, three, and four instars were 13, 82, and 5%, respectively. Female L. brunnea have three to five instars, and the percentages of females with three, four, and five instars were 18, 78, and 4%, respectively. The life cycle was shorter for males than females. We developed temperature-dependent development equations for male and female eggs, individual nymphal, combined nymphal, and combined immature stages and nymphal survivorship. The ability of L. brunnea to multiply rather rapidly at 55% RH may allow it to thrive under conditions of low relative humidity where other Liposcelis species may not. These data give us a better understanding of L. brunnea population dynamics and can be used to help develop effective management strategies for this psocid.

We studied the temporospatial distribution of psocids in steel bins containing 32.6 tonnes of wheat in 2005 and 2006 in Manhattan, KS. Psocids were sampled in the top 0.9 m of wheat using a 1.2-m open-ended trier; samples were taken from the bin center and in the four cardinal directions at 0.15 and 0.76 m from the bin wall. In addition, a 2.4-m partitioned grain trier with 16 compartments was used to sample psocids from a 2-m-diameter circle in the center of the bins and to a depth of 1.96 m. Only two species of psocids were identified in the study: Liposcelis entomophila in 2005 and L. decolor in 2006. Densities of psocids were low immediately after bins were filled in July 2005, peaked in October, dropped to almost zero in December as temperatures decreased, and remained at low levels until the study was ended in March. In 2006, densities of psocids increased gradually from August to mid-October and declined until the study was ended in early November. During the fall, psocids were more abundant at the center of the bin and at lower depths. In October to November of both years, the temperatures and moisture contents of grain in the center also were higher than that in other locations. This is the first report of temporospatial distribution of psocids in steel bins of wheat.

An evaluation of five sampling methods for studying psocid population levels was conducted in two steel bins containing 32.6 tonnes of wheat in Manhattan, KS. Psocids were sampled using a 1.2-m open-ended trier, corrugated cardboard refuges placed on the underside of the bin hatch or the surface of the grain, and manual or automated electronic counts from Insector probe traps. Only two species were identified in this study: Liposcelis entomophila (Enderlein) in 2005 and L. decolor (Pearman) in 2006. In both years, psocid numbers started to increase in early September, peaked earliest in surface refuges, and peaked at nearly the same time in grain samples and manual and electronic Insector counts. No psocids were found in hatch refuges in December to February, although psocids were detected by the other sampling methods during this time. Numbers of psocids in the grain samples could be estimated from the numbers of psocids obtained using the cardboard refuges and Insector probe traps in both years. The results indicate that cardboard refuges or Insectors may provide an effective method for sampling psocids in bins of wheat.

The medical and veterinary pest Musca domestica L. has developed resistance to most insecticides used against it. For this reason, there is a constant search for new alternative control tools. The aims of this study were (1) to evaluate the toxicological effects caused by the fumigant activity and the topical application of five essential oils and five monoterpenes in M. domestica adult males and (2) to study the variation of the fumigant activity of the essential oils and monoterpenes according to the solvent used (acetone or a silicone base). Houses flies were exposed to vapors delivered by filter paper treated with 200 µl of essential oil or monoterpene (10%) in acetone or a silicone base. The knockdown time 50% (KT₅₀) values obtained for essential oils (expressed in minutes) were 3.3 (eucalyptus); 10.1 (orange); 10.4 (mint); 10.9 (lavender); and 17.7 (geranium). The KT₅₀ values obtained for monoterpenes (expressed in minutes) were 2.3 (eucalyptol); 7.5 (limonene); 7.6 (linalool); 19.0 (menthone); and 22.6 (menthyl acetate). In all cases, a delay in the onset of poisoning symptoms was observed when a silicone base vehicle was used. When topically applied, the lethal dose 50% (LD₅₀) values for essential oils (expressed in micrograms of oil/insect) were 0.07 (geranium); 0.09 (mint); 0.13 (lavender); 0.14 (eucalyptus); and 0.16 (orange). The LD₅₀ values for monoterpenes (expressed in micrograms of monoterpene/insect) were 0.04 (linalool); 0.09 (menthyl acetate); 0.10 (limonene); 0.11 (menthone); and 0.13 (eucalyptol). These results suggest that the studied essential oils and monoterpenes are potential tools for controlling M. domestica.

We tested the utility of 18 previously characterized Aphis spp. microsatellite loci for polymorphism and differentiation among populations of the soybean aphid, Aphis glycines. Loci were chosen from a closely related species (Aphis gossypii) and a more distantly related species (Aphis fabae). We found nine loci to be polymorphic among Korean and North American populations. Overall expected heterozygosity was moderate (average: 0.47; range: 0–1), although populations substantially differed in deviations from Hardy-Weinberg equilibrium. These loci will be valuable in characterizing population differentiation, migration and adaptation in an economically important pest of soybeans.

In studying the dynamics of ant nest excavation, the nest volume has to be continuously monitored. In many laboratory studies, the excavated substrate, such as sand, was collected, and the volume of excavation was calculated by converting the weight of the collected sand into the volume. The excavated sand can be manually collected and weighed; however, manual collection is tedious, particularly when frequent collections have to be performed for a period of several days. Manual collection may also introduce disturbance to the ants. The volume of excavation can also be monitored using a video system by transferring images into volume data. Unfortunately, it requires sophisticated software customization. A simple automatic system for continuously collecting and weighing the excavated sand is described. This system does not disturb the ants while collecting data and requires no software customization. It can display the digging curves while it is still collecting data.

Experiments tested the ability of newly emerged spiderlings of a black widow spider, Latrodectus hesperus Chamberlin & Ivie (Araneae: Theridiidae), to crawl through brass screen of various mesh size. The purpose was to determine whether immatures of these medically important spiders could be excluded from buildings. In horizontal orientation, black widow spiderlings were able to easily pass through mesh with openings of 0.83 mm and were prevented from passing in four of five tests with mesh of 0.59-mm openings. Spiderlings also readily pass through 0.83-mm mesh in vertical orientation. Our laboratory studies indicate that the mesh size sufficient for exclusion is too small for practical use in most cases, although there are some specialized situations where such small mesh might be useful. The results are discussed in regard to actual conditions found in typical commercial building situations.