Illustrated keys to adults reflecting the current higher classification are provided for families of Cicadomorpha (cicadas, spittlebugs, leafhoppers, and treehoppers) and for subfamilies and tribes of Cicadellidae (leafhoppers), excluding Deltocephalinae. The following families (and superfamilies) are recognized: Cicadidae and Tettigarctidae (Cicadoidea); Aphrophoridae, Cercopidae, Clastopteridae, Epipygidae, and Machaerotidae (Cercopoidea); Aetalionidae, Cicadellidae, Melizoderidae, Membracidae, Myerslopiidae (Membracoidea). The higher classification of Cicadellidae is currently undergoing revision, but a provisional key to subfamilies and tribes (except Deltocephalinae) is provided. Two new synonymies are proposed: Signoretiinae Baker, 1915 equals Phlogisinae Linnavuori, 1979, new synonym; Iassini Walker, 1870, equals Hyalojassini Evans, 1972, new synonym.
The hemipteran (=homopteran) infraorder Cicadomorpha comprises approximately 35,000 described species of plant sap-sucking insects distributed worldwide. Species are grouped into three superfamilies that are well established based on morphological criteria: Cicadoidea (cicadas); Cercopoidea (spittlebugs, froghoppers); and Membracoidea (leafhoppers, sharpshooters, treehoppers) (Fig. 1 and Fig. 2). Cicadomorpha may be distinguished from other Hemiptera by the following combination of characters: postclypeus enlarged; antennal pedicel small, without conspicuous sensilla, flagellum aristiform; tegulae absent; forewing anal veins usually separate from base to wing margin; middle coxae small and narrowly separated. Over 3,000 species of Cicadomorpha are recorded from temperate North America, including ca. 70 exotic species, the vast majority of which are native to Eurasia. Relatively few species are economically important, but there are some major pests, such as the glassy-winged sharpshooter, Homalodisca coagulata (Say), potato leafhopper, Empoasca fabae (Harris), and beet leafhopper, Neoaliturus (=Circulifer) tenellus (Baker). Cicadomorphans injure plants either directly through feeding (Backus 1988; Backus et al. 2005) or indirectly through transmission of plant pathogens (Nielson 1968; Maramorosch & Harris 1979).
Identification of cicadomorphan species is difficult because of their tremendous diversity and the paucity of comprehensive identification keys. Recent sampling suggests that more than 90% of the extant tropical cicadomorphan species remain undescribed (Hodkinson & Casson 1991; Dietrich & Wallner 2002, unpublished data). These, as well as a large proportion of described species, have never been included in a key. Thus, when possible at all, identification of cicadomorphan species usually requires access to a large and obscure taxonomic literature and authoritatively identified reference specimens.
Recent phylogenetic analyses (e.g., Dietrich & Deitz 1993; Dietrich 1999; Dietrich et al. 2001a, Dietrich et al. 2001b; Shcherbakov 1996; Rakitov 1998; Hamilton 1999; Wallace & Deitz 2004; Cryan et al. 2004; Moulds, unpublished) have begun to elucidate the status and relationships of cicadomorphan family-group taxa, but the higher classification of Cicadomorpha remains controversial and no family-group classification has yet gained universal acceptance. Due in part to this controversy, few attempts have been made recently to develop keys for identifying the major cicadomorphan groups (families, subfamilies, and tribes). Although revised keys are available for treehopper family-group taxa (Deitz & Dietrich 1993; Dietrich et al. 2001b; Wallace & Deitz 2004), the most recent comprehensive key to leafhopper subfamilies and tribes is over 50 years old (Evans 1947). The most comprehensive keys to cicada and spittlebug family groups are nearly 100 years old (Distant 1912, Distant 1914; Lallemand 1912). More recent keys are available for certain regional faunas (e.g., Evans 1966; Anufriev & Emeljanov 1988), but interpretations of higher taxa vary among regions and authors. The family-group classifications of cicadas (Moulds, unpublished) and cercopoids (Hamilton, Liang, unpublished) are currently being revised. Revisions to the higher classification of leafhoppers have also been made in recent years. Hamilton (1983) proposed a classification of Cicadellidae that included only ten subfamilies, but subsequent authors have not followed his system. Oman et al. (1990) recognized 40 subfamilies and 119 tribes in their provisional classification and world generic checklist. Subsequent to the 1985 cut-off date for the Oman et al. (1990) checklist, a new subfamily (Godoy & Webb 1994) and two new tribes (Theron 1986; Hamilton 1999) have been described. Also, several family-group taxa listed as valid by Oman et al. (1990) have more recently been treated as junior synonyms (e.g., Dietrich & Rakitov 2002; Dietrich & Dmitriev 2003; Dietrich 2004).
The purpose of this paper is to provide up-to-date keys to the families of Cicadomorpha and to subfamilies and tribes of Cicadellidae that reflect, to the extent possible, current consensus regarding the higher classifications of these groups.
Morphology
The following section describes the basic morphological terminology used in keys to Cicadomorpha but is not intended as an exhaustive treatment. For a more detailed treatment of cicadomorphan morphology, see Kramer (1950). Alternative terminologies have been proposed by various authors (e.g., Blocker & Triplehorn 1985; Hamilton 1981; Mejdalani 1998). There is not yet a universally accepted system of morphological terminology for Cicadomorpha. For a detailed treatment of the morphology of cicadellid nymphs, see Dmitriev (2002).
Head. The cicadomorphan head is highly variable in form, particularly among leafhoppers (Fig. 3A, 3B, and Fig. 4). For convenience, the term face is used to refer to the anterior part and the term crown refers to the dorsal part, although in different groups these areas are made up of parts of different sclerites. Some authors (e.g., Blocker & Triplehorn 1985) use crown and vertex interchangeably, but the term vertex is correctly applied only to the pair of sclerites posterolaterad of the frontal sutures and bearing the lateral ocelli. The rostrum (or beak), the modified labium, varies in length among taxa. The clypeus is almost always divided by the clypeal (or transclypeal) suture into two sclerites, the anteclypeus (clypellus) and postclypeus, both of which vary in texture and proportions among taxa. The postclypeus is usually not clearly divided from the frons dorsally, thus the term frontoclypeus is often used to refer to the combined sclerite, which is usually the largest structure of the head in anterior view. Immediately laterad of the clypeus on the lower part of the face is a pair of mandibular plates called the lora (singular-lorum), which vary in size, shape, and relative position. The lorum is situated on the maxillary plate, which, along with the more dorsally situated gena, forms the lateral margin of the head. In most leafhoppers, the gena and maxillary plate are fused, but a few groups of leafhoppers (e.g., Ulopinae), as well as most other cicadomorphans, have the maxillary plate and gena separated by a distinct suture or cleft. The antennae of Cicadomorpha consist of two short basal segments and an elongate flagellum, which varies in length and shape and may be subsegmented to various degrees. The base of the antenna may be partly covered dorsally by an outgrowth of the vertex called the antennal ledge, which also varies in shape and may extend onto the frontoclypeus. The eyes vary in size and shape, and the ocelli vary in their position relative to the eyes and to the anterior margin of the head. The lateral arms of the epicranial suture, usually termed frontal sutures, are reduced or lost in various taxa and their relative shape and position also varies. In many leafhoppers, these sutures extend to the ocelli and in such cases are often referred to as lateral frontal sutures (or laterofrontal sutures).
Thorax (Fig. 5). The pronotum of Cicadomorpha varies in shape, ornamentation, texture and proportions, particularly in treehoppers (Fig. 2F), which usually have a well developed posterior process that partially or completely conceals the scutellum and may also overlap the wings. The mesonotum and scutellum, divided by the scutellar suture (and often incorrectly referred to collectively as the “scutellum”), vary in proportions and the degree to which they are concealed by the pronotum. Important pleural sclerites include the proepisternum, the mesepisternum, and mesepimeron, which vary in proportions and, in the latter, may bear tubercles or other processes. The mesepisternum is usually divided into an anterodorsal anepisternum and a posteroventral katepisternum, but these two sclerites are fused in treehoppers. The forewing, or tegmen (pl., tegmina), and hind wing vary in proportions, texture, and venation. Important features of the wings include the branching pattern of veins and the shape and texture of the cells (areas between veins).
The legs vary in shape, proportions, spination, and chaetotaxy (setal arrangement). Different systems have been proposed for naming the rows and groups of setae on the legs of leafhoppers (Rakitov 1998) and treehoppers (Deitz 1975). In Rakitov's system, adopted here, longitudinal rows of setae are labeled according to their position assuming that the leg is extended perpendicular to the mid-saggital plane of the body; i.e., anterodorsal (AD), posterodorsal (PD), anteroventral (AV) and posteroventral (PV) (Figs. 7G, 7J). The front femur of leafhoppers often bears additional anteromedial (AM) and intercalary (IC) setal rows (Fig. 7K). When appropriate, individual setae are numbered sequentially, beginning with the most distal (e.g., AV1 referrs to the distal seta of the anteroventral row). Setal formulae are often used to describe the arrangement of enlarged setae, or macrosetae, particularly on the front tibia and hind femur. In treehoppers, the number and arrangement of rows of cucullate setae (setae with dark, hoodlike basal sockets) on the hind tibia are important for distinguishing tribes.
Abdomen. The basal segments of the abdomen and adjacent parts of the metathorax are modified, particularly in males, for sound production. In cicadas, the structure of these sound producing organs, or tymbals, varies among species. The organs of sound detection in cicadas, or tympana, are located ventrally at the base of the abdomen and may be concealed by opercula, which are flaplike outgrowths of the metathorax. Similar structures may occur in other cicadomorphans, but they are not as well developed. In some groups of leafhoppers, the shapes of the internal apodemes of male abdominal segments I-III, associated with the production of species-specific courtship signals transmitted through the substrate, are diagnostic at the species level.
The male genital capsule (Figs. 3C-E) consists of the tergite of segment IX, or pygofer (pygophore), and the sternite of segment IX, or valve, which may or may not be separated from each other by a suture. The pygofer varies in shape and chaetotaxy, and may bear various lobes or processes. In Membracoidea and Cercopoidea, there is a pair of posteroventral lobes called subgenital plates (or, simply, plates) connected to the posterior margin of the valve; these vary in shape, chaetotaxy, and degree of fusion to each other and to the valve. The sclerotized parts of the genitalia of Membracoidea and Cercopoidea consist of a pair of lateral styles, a median connective, and an aedeagus or penis, all of which vary in shape and proportion and may be highly modified with various processes and accessory structures. In cicadas, the styles and connective are vestigial. Segment X, which forms the major part of the anal tube, also varies in shape and proportion and may bear spines or processes.
The female ovipositor (Fig. 3F) consists of two pairs of blade-like structures, the first and second valvulae, and an outer sheath, the third valvulae (gonoplacs). The second valvulae vary in shape, proportion and armature (dorsal teeth or serrations). The first valvulae, which enclose the second, vary in shape, proportion, and texture. When not in use, the ovipositor is partially enclosed by the enlarged ninth abdominal tergite, or pygofer. The seventh abdominal sternite usually overlaps the bases of the ovipositor and pygofer ventrally and varies in shape among species in some groups.
Identification
The following key will separate adults of the superfamilies and families of Cicadomorpha. The family classification of Cicadoidea follows that of Moulds (1990); see Duffels & van der Laan (1985) for an alternative classification. That of Cercopoidea follows Metcalf (1960-1962); but see Hamilton (2001) for an alternative classification. That of Membracoidea follows Deitz & Dietrich (1993) and Hamilton (1999).
Key to Families of Cicadomorpha
1.Head with three ocelli arranged in triangle on crownCicadoidea
1'. Head with two ocelli, variously positioned, or ocelli absent
2(1). Pronotum extended to scutellar suture (Fig. 1A)
2'. Pronotum not extended to scutellar suture (Fig. 1B)
3(1'). Hind coxa conical (Fig. 5C); tibia cylindrical, often with one or more large preapical spines, but never with rows of enlarged setae; ocelli on crown; body and wing surfaces clothed with fine setaeCercopoidea
3'. Hind coxa transverse (Fig. 5F); tibia quadrate, usually with conspicuous longitudinal rows of enlarged setae; ocelli variously positioned; body and wings without a conspicuous vestiture of fine setaeMembracoidea
4(3). Scutellum much longer than wide; antennal pits deep, concealing antennal base; body length including forewings at rest usually 7 mm or less
4'.Scutellum little if any longer than wide; antennal pits relatively shallow, base of antenna visible; body length including forewings usually > 7 mm
5(4). Forewing apices broadly overlapping at rest (Fig. 1D)
5'. Forewing apices not overlapping at rest (Fig. 1E) (Paleotropical)
6(4'). Eye depressed and oblong, distinctly wider than high, less than half its width from forewing base
6'. Eye globular, no wider than high, usually more than its width from forewing base
7(6). Frontoclypeus flattened or concave laterally; eye touching or overlapping forewing base (Neotropical)
7'. Frontoclypeus convex throughout; eye not reaching forewing base
8(3'). Mesanepisternum separated by suture from katepisternum, without dorsal hooklike process (Fig. 5E); pronotum rarely extended to scutellar suture (Signoretiinae), never overlapping scutellum; hind tibia with setae of longitudinal rows usually large and conspicuous
8'. Mesepisternum not divided by suture, usually with hooklike process dorsally (Fig. 5G); pronotum usually reaching or extending over scutellar suture or, if not, scutellum strongly produced or keeled dorsally; hind tibia with setae of longitudinal rows small and inconspicuous
9(8). Forewing elytralike (Fig. 2A), hind wing vestigial; mesothoracic coxa with acute basolateral process (Fig. 5B) (Chile and New Zealand)
9'. Wings variously developed; if forewing elytralike and hind wing vestigial, then mesothoracic coxa without acute basolateral process
10(8'). Pronotum extended posteriorly over and often largely or entirely concealing scutellum or, if scutellum completely exposed, then scutellum with distinct median posterior groove or emargination, or forewing veins M and Cu forming common stem separate from R basally, or bothMembracidae
10'. Pronotum not extended posteriorly over scutellum, scutellum completely exposed; forewing veins R and M forming common stem basally or M not clearly united with either R or Cu
11(10'). Frontoclypeus flat or weakly convex, not produced anteroventrally (Fig. 2E); prothoracic trochanter and femur fused; female pygofer produced posteroventrally (Neotropical and Oriental)
11'. Frontoclypeus strongly convex, produced anteroventrally (Fig. 2D); prothoracic trochanter and femur not fused; female pygofer not produced posteroventrally (Chile)
The interpretation of leafhopper subfamilies and tribes in the following key is based on that of Oman et al. (1990), but with several important exceptions that reflect ongoing revisionary work on the higher classification of Cicadellidae. Following Hamilton (1983), the typhlocybine tribe Helionini is treated as a synonym of Empoascini, and Petalocephalini is treated as a synonym of Ledrini. Following Hamilton (1983), Hamilton (1999), Agalliinae, Evansiolinae, and Adelungiinae are considered synonyms of Megophthalminae; these taxa, sensu Oman et al. (1990), are here recognized as tribes within Megophthalminae (sensu lato). Neopsinae is retained at subfamily rank, following Linnavuori (1978) rather than as a tribe of Macropsinae.
The interpretation of Neocoelidiinae follows Dietrich (2003). Following Dietrich (2004), Nirvaninae is treated as a synonym of Evacanthinae, which includes tribes Evacanthini, Nirvanini, Pagaroniini, and Balbillini. Also following Dietrich (2004), Macroceratogoniini is included as a tribe of Coelidiinae rather than of Evacanthinae. Following Young (1968), Young (1986) and Linnavuori & DeLong (1977), Errhomeninae (= Bathysmatophorini) and Mileewinae are treated as subfamilies distinct from Cicadellinae. Thus, the present interpretation of Cicadellinae follows Young (1968), Young (1977) in including only the tribes Cicadellini and Proconiini.
Scarini (=Gyponini) is treated as a tribe of Iassinae following Linnavuori & Quartau (1975), rather than as a distinct subfamily. Following Hamilton (1975), Xestocephalinae is treated as a synonym of Aphrodinae. Following Dietrich & Rakitov (2002) and Dietrich & Dmitriev (2003), the following subfamilies (sensu Oman et al. 1990) are considered synonyms of Deltocephalinae: Eupelicinae, Koebeliinae, Paraboloponinae, Penthiniinae, and Selenocephalinae. The name Penthimiinae Kirschbaum, 1868, has priority over Deltocephalinae Dallas, 1870, but the latter name is provisionally retained in view of its long-term usage and because the classification of Deltocephalinae is undergoing revision.
The monobasic subfamily Phlogisinae Linnavuori, 1979, is treated as a junior synonym of Signoretiinae Baker, 1915 (new synonymy), and the monobasic tribe Hyalojassini Evans, 1972, is treated as a junior synonym of Iassini Walker, 1870 (new synonymy), based on shared characters given in the key.
Two family-group taxa described after the publication of the Oman et al. (1990) checklist are added: Tinterominae, a subfamily described by Godoy & Webb (1994); and Sagmatiini, a tribe of Euacanthellinae described by Hamilton (1999). The endemic South African tribe Equeefini Theron, 1986 (Coelidiinae), is excluded because sufficient material was not available for study. The subfamilies Acostemminae, Arrugadinae, Drakensbergeninae, Mukariinae, and Stegelytrinae, and the tribe Paraphrodini (Aphrodinae) are also excluded. These taxa key to Deltocephalinae and are the subject of an ongoing phylogenetic study and revision of the “deltocephaline-like” leafhoppers (Zahniser & Dietrich, unpublished).
Key to Subfamilies and Tribes of Cicadellidae
1. Hind tarsomere I acuminate (Fig. 7O), without transverse row of blunt setae; forewing fully developed and without closed anteapical cells (Fig. 6F); small (usually < 5 mm), delicate leafhoppers Typhlocybinae
1'. Hind tarsomere I truncate distally (Fig. 7P), usually with transverse row of blunt setae (platellae); forewing usually with one or more closed anteapical cells, or brachypterous; size various, usually not small and delicate
2(1). Forewing with appendix (Fig. 3A)
2'. Forewing without appendix (Fig. 6F)
3(2'). Hind wing with submarginal vein present at wing apex (Fig. 3A)
3'. Hind wing submarginal vein absent at wing apex (Fig. 6K, M)
4(3). Hind wing submarginal vein extended around wing apex, continuous with vein R2+3 (Fig. 3A)
4'. Hind wing vein vein R2+3 absent, or if present, not continuous with submarginal vein (Figs. 6M-O)
5(4'). Hind wing with R4+5 and M1+2 free, connected by crossvein (Fig. 6O) (New World)
5'. Hind wing with R4+5 and M1+2 confluent distally (Fig. 6N)
6(3'). Hind wing vannal vein unbranched (Fig. 6M); forewing inner apical cell elongate, extended to apex; face with lorum well separated from margin of maxillary plate ventrally
6'. Hind wing vannal vein branched (Figs. 6K); forewing inner apical cell short, oblique, not extended to apex (Fig. 6F); face with lorum extended to lower margin of maxillary plate
7(6'). Hind wing with distal segment of CuA absent, submarginal vein apparently connected directly to CuA preapically (Old World)
7'. Hind wing with distal segment of CuA present, submarginal vein apparently connected to CuA by crossvein (Fig. 6K)
8(1'). Mesanepisternum with horizontal keel; head and pronotum coarsely pitted; setae of hind tibial rows small and inconspicuous; head with maxillary plate and gena separated by distinct cleft (Old World)Ulopinae
8'. Mesanepisternum not keeled (Fig. 5F); head and pronotum with or without coarse pits; hind tibia with well developed macrosetae; head with maxillary plate and gena fused, at most separated by suture
9(8). Body elongate, seed shaped; head more than 2× longer than pronotum (South Africa, Australia)
9'. Body robust, ovoid; head usually less than 2× longer than pronotum
10(9'). Ocelli absent; forewing sexually dimorphic, that of male short and truncate, that of female emarginate apically (New Guinea)
10'. Ocelli usually well-developed, on crown; forewings not sexually dimorphic
11(8'). Hind femur with only 3 short, stout macrosetae grouped at apex (Fig. 7E); proepisternum large, not concealed by gena (Fig. 4G)Ledrinae
11'. Hind femur without 3 short, stout macrosetae grouped at apex, if only three macrosetae present on femur, then one distinctly preapical (Fig. 7D); proepisternum concealed or exposed
12(11). Anterior margin of pronotum weakly produced, not extended as far as anteromedial corners of eyes (Fig. 4I); ocelli on crown distant from margin; head usually spatulate
12'. Anterior margin of pronotum produced to or anterad of anteromedial corners of eyes (Fig. 4J); ocelli position variable, if on crown, not distant from margin; head usually not spatulate (Australia)
13(12). Forewing appendix well developed, extended around wing apex (Fig. 6G) (New World)
13'. Forewing appendix greatly reduced or absent (Fig. 6F)
14(12'). Rostrum elongate, extended to or beyond hind coxae; forewing anal veins confluent distally
14'. Rostrum not extended to hind coxae; forewing anal veins free
15(11'). Ocelli absent, wings vestigial, overall habitus beetlelike
15'. Ocelli on face, distinctly below margin of crown (Fig. 4D) and not visible from above; hind femur macrosetal formula usually 2+1 (Figs. 7D, E) or 2+0, rarely 2+1+1 (Fig. 7C)
15”. Ocelli on crown (Fig. 4K) or on anterior margin of head (Figs. 4B, C); if crown not delimited and head broadly rounded in profile, or ocelli distinctly below sharply delimited crown margin, then hindwing veins R4+5 and M1+2 confluent distally, or middle trochanter with stout ventral seta, or hind femur macrosetal formula 2+2+1 (Figs. 7A, B)
16(15).Abdomen with prominent paired dorsal tubercles (Australia, Madagascar)
16'. Abdomen without paired dorsal tubercles (Juan Fernandez Islands, Chile)
17(15'). Pronotum strongly produced, anterior margin extended anterad of eyes (Fig. 4J)
17'. Pronotum not or weakly produced, anterior margin not extended anterad of eyes (Fig. 4I)
18(17). Proepisternum large, not concealed by gena (Fig. 4G); hind wing vein R2+3 absent, submarginal vein not extended along costal margin basad of R4+5 (Fig. 6I) (worldwide except Neotropical)
18'. Proepisternum small, entirely concealed by gena; hind wing vein R2+3 present (Fig. 3A), submarginal vein extended along costal margin basad of R4+5
19(18'). Head with lateral frontal sutures obsolete; hind tibia row AD with small cucullate setae between larger macrosetae; coloration pale with darker markings on head and pronotum (South America)
19'. Head with lateral frontal sutures well developed; hind tibia row AD with intercalary setae, when present, not cucullate; coloration black or reddish brown, without distinct markings
20(19'). Forewing crossvein s present (Fig. 6A), anal veins connected by crossvein; male with aedeagal shaft undivided, with single gonopore (Old World)
20'. Forewing crossvein s usually absent, anal veins not connected by crossvein; male with aedeagal shaft divided, with two gonopores (New World)
21(17'). Forewing distinctly and densely granulose; hind tibia macrosetal row PD with 0-1 more macrosetae than row AD; ovipositor with first valvula sculpturing not strigate
21'. Forewing glabrous; hind tibia macrosetal row PD with many more macrosetae than row AD; ovipositor with first valvula sculpturing strigate
22(21). Face and pronotum coarsely punctate; frontal sutures carinate (Europe, Africa, and western North America)
22'. Face and pronotum not, or only sparsely punctate; frontal sutures when present not carinate
23(22'). Forewing venation reticulate; clypeal suture well developed, transverse (North Africa, Middle East, and Central Asia)
23'. Forewing venation not reticulate (rarely with a few extra crossveins); clypeal suture arcuate, obsolete medially
24(21'). Head with crown short but distinctly delimited, flat (Australia)
24'. Head with crown poorly delimited, convex, rounded to face
25(24'). Forewing with crossvein r-m1 elongate, connected between R2+3 and R4+5 (or R with supranumerary branches), with three m-cu crossveins; hind femur in repose not reaching prothorax (Australia)
25'. Forewing crossvein r-m1, if present, short, oblique, connected between R1 and R2+3, with two m-cu crossveins (Fig. 6E), or if three present, then s crossvein present and membrane not opaquely sclerotized; hind femur in repose reaching prothorax (worldwide, including Australia)
26(25). Head narrower than hind margin of pronotum; hind tibia row AD with macrosetae evenly distributed and subequal in size
26'. Head as wide as or wider than hind margin of pronotum; hind tibia row AD with distal setae enlarged with spinose bases
27(26'). Forewing opaquely sclerotized; male plates with accessory processes
27'. Forewing translucent; male plates without accessory processes
28(15”). Forewing with inner apical cell elongate, vein M3+4 connected to submarginal vein near wing apex (Fig. 6A), or, if forewing reduced (brachypterous), then crown elevated and shelflike mesad of eyes (Fig. 4A); crown between eyes less than twice as wide as median length; anterior margin of pronotum not extended anterad of eyes in dorsal view
28'. Forewing with inner apical cell shorter (rarely narrow and elongate, Fig. 6D), distal segment of vein M3+4 convergent toward commisural margin and connected to submarginal vein well basad of wing apex (Figs. 3A, Figs. 6B-F); or, if M3+4 connected to submarginal vein near wing apex or forewing brachypterous, then crown between eyes more than twice as wide as long, not elevated and shelflike mesad of eyes, and/or anterior margin of pronotum extended anterad of eyes in dorsal view
29(28). Rostrum with distal segment ≥2× longer than penultimate segment; antennal base in anterior view adjacent to anteroventral corner of eye, ledge absent or very weak; crown width between eyes usually less than eye width; front tibia with accessory row of setae between rows AD and AV
29'. Rostrum with distal segment little, if any, longer than penultimate segment; antennal base in anterior view near mid-height of eye, ledge well-developed; crown width between eyes greater than 1.5× eye width; front tibia without accessory row of setae between rows AD and AV
30(29). Base of forewing concealed by pronotum; usually brachypterous (New World)
30'. Base of forewing exposed; very rarely brachypterous
31(30'). Pronotum bicarinate laterally, crown with pair of arcuate longitudinal keels (Neotropical)
31'. Pronotum unicarinate laterally, crown without keels
32(31'). Crown distinctly elevated above level of eyes, usually strongly produced anteriorly and with distinct striations convergent toward apex (Fig. 4A); male subgenital plate usually appearing two-segmented
32'. Crown weakly or not elevated above level of eyes, weakly produced anteriorly and usually without distinct longitudinal striations; male plate not two-segmented
33(32). Aedeagus with a single shaft and symmetrical, fused to connective; subgenital plate sparsely setose (Afrotropical)
33'. Aedeagus bipendulate or asymmetrical, articulated to connective; plate profusely setose
34(33'). Aedeagus with two shafts (except Neotharra); style claw- or hooklike apically (Paleotropical)
34'. Aedeagus with single shaft; style not clawlike, rarely hooklike apically (Neotropical)
35(32'). Frontoclypeus with complete median longitudinal carina (Fig. 4A)
35'. Frontoclypeus without or with partial median longitudinal carina
36(35'). Prothoracic tibia and femur flattened or foliaceous (Neotropical)
36'. Prothoracic tibia and femur slender
37(29'). Forewing membrane clothed with setae and/or scales; abdomen strongly depressed (Afrotropical and Oriental)
37'. Forewing membrane without setae or scales; abdomen tectiform
38(37'). Hind femur macrosetal formula 2+2+1 (Figs. 7A, B) or with supranumerary setae
38'. Hind femur macrosetal formula 2+1+1 (Fig. 7C), 2+1 (Fig. 7D, E), or 2+0
39(38). Anterior margin of head with, at most, a single transverse carina; hind wing veins R4+5 and M1+2 usually confluent apically (Fig. 6J) (New World only)
39'. Anterior margin of head with more than one transverse carinae or with irregular striations; hind wing veins R4+5 and M1+2 free, connected by crossvein
40(39'). Frontoclypeus strongly inflated (eastern Palearctic and western Nearctic)
40'. Frontoclypeus flat (N. Australia and New Caledonia)
41(38). Pronotum extended to scutellar suture, coarsely punctate (Afrotropical and Oriental)
41'. Pronotum not extended to scutellar suture (Fig. 3A, Fig. 5D), punctations indistinct or absent
42(41'). Forewing fully developed, vein r-m1 absent (Fig. 6B); frontoclypeus with partial or complete median longitudinal carina (Fig. 4A); or if carina absent, frontoclypeus strongly flattened medially, or front femur with single enlarged ventral seta near midlength (Fig. 7N), or both
42'. Forewing fully developed with vein r-m1 present (Fig. 3A) or brachypterous; or, if forewing fully developed and r-m1 absent, then frontoclypeus without median carina and not strongly flattened medially, and front femur without single enlarged ventral seta near midlength
43(42'). Frontoclypeus with complete median carina (Fig. 4A)
43'. Frontoclypeus with median carina incomplete or absent
44(43'). Pro- and mesothoracic tibiae flattened; crown notched anterad of eye, scape of antenna visible in dorsal view (Paleotropical)
44'. Pro- and mesothoracic tibiae cylindrical; crown entire, concealing scape in dorsal view (Fig. 4K)
45(42'). Hind wing submarginal vein on or very near wing margin apically (Fig. 6L) (rare inhabitants of tropical cloud forests)
45'. Hind wing submarginal vein well separated from apical margin (Fig. 3A)
46(45). Crown margin distinctly carinate; pronotum extended nearly to scutellar suture, distinctly punctate (Philippines)
46'. Crown margin not carinate; pronotum not extended nearly to scutellar suture, puctures if present small and indistinct
47(46'). Forewing crossvein r-m1 present, appendix inconspicuous; hind tarsus more than half length of tibia (Neotropical)
47'. Forewing crossvein r-m1 absent, appendix well developed; hind tarsus less than half length of tibia (Pantropical)
48(45'). Antennal ledge in dorsal view prominent; hind femur in repose not attaining posterolateral margin of prothorax (New World)
48'. Antennal ledge in dorsal view not prominent; hind femur in repose usually attaining posterolateral margin of prothorax
49(48). Body cylindrical, crown margin not or indistinctly carinate
49'. Body strongly depressed, crown margin sharply carinate (South America)
50(28'). Proepisternum large, not concealed by gena (Fig. 4G); head in dorsal view little, if any, longer than wide; ocelli on crown well separated from margin
50'. Proepisternum small, concealed by gena (Fig. 4H), or if proepisternum exposed, then head in dorsal view more than twice as long as wide and ocelli on or very near crown margin
51(50). Gena acutely emarginate or with deep antennal grooves; hind femora without supranumerary macrosetae (Australia)
51'. Gena not acutely emarginate, without antennal grooves (Fig. 4E); hind femur with supranumerary macrosetae (Holarctic)
52(50'). Front tibia with distinct accessory longitudinal row of setae adjacent to row AV on anterior surface near base; male subgenital plates fully exposed, constricted basally, broadened distally (Neotropical)
52'. Front tibia without accessory row of setae adjacent to row AV on anterior surface (scattered setae may be present); male subgenital plates of various shapes, sometimes concealed by sternite VII
53(52'). Head with lateral frontal sutures partly or completely obsolete and not extended to ocelli; if head >2× longer than wide in dorsal view then ocelli not on or slightly above crown margin; male valve and subgenital plates partly to completely concealed by enlarged abdominal sternite VIII
53'.Head with lateral frontal sutures well developed and extended to or very near ocelli; or, if lateral frontal sutures not extended to ocelli, then either head >2× longer than wide in dorsal view and ocelli on or slightly above or below crown margin, or male valve and subgenital plates not concealed by enlarged abdominal sternite VII, or both
54(53). Hind wing veins R4+5 and M1+2 confluent near apex (Fig. 6J), or if veins free, then head in profile broadly rounded, without distinctly delimited crown
54'. Hind wing veins R4+5 and M1+2 free (Fig. 6H-I), crown well delimited
55(54). Crown strongly depressed and produced, margin well delimited
55'. Crown convex, not or only weakly produced, rounded to face
56(55). Ocelli on or near margin of crown (Australia)
56'. Ocelli on crown, distant from margin (Madagascar)
57(55'). Head distinctly bent at right angle across antennal ledges, crown vertical and forming continuous curve with strongly declivous pronotum (Australia)
57'. Head with crown and face more or less evenly convex, pronotum usually weakly declivous
58(54'). Ocelli on crown distant from marginScarini
58'. Ocelli on anterior margin of head
59(58'). Forewing with venation reticulate distally, inner apical cell narrow, acuminate (Paleotropical and Caribbean)
59'. Forewing venation with, at most, 1-2 supranumerary crossveins, inner apical cell broad (New Caledonia)
60(53'). Pronotum strongly produced, anterior margin extended anterad of eyes (Fig. 4J)
60'. Pronotum not or weakly produced, anterior margin not extended anterad of eyes (Fig. 4I)
61(60). Hind tibia macrosetal row AD with small cucullate setae interspersed between large setae; forewing membrane without conspicuous setae (Australia)
61'. Hind tibia macrosetal row AD without cucullate intercalary setae; forewing membrane with conspicuous setae (South America)
62(60'). Front femur row AV with single stout seta near midlength; female with ovipositor distinctly arcuate
62'. Front femur row AV with more than one stout seta or setae absent near midlength; female with ovipositor straight or somewhat recurved
63(62'). Forewing anal veins free, clavus without crossveins; male subgenital plates constricted basally, widest near or beyond midlength (Fig. 3E); valve with posterior margin not angulately produced; style slender, not broadly bilobed basally
63'. Forewing with or without one or more crossveins in clavus, or anal veins partially confluent; male subgenital plates not constricted basally, widest near base and tapered toward apex (Fig. 3D); valve with lateral margin short and posterior margin usually distinctly produced and angulate medially (Fig. 3D); style usually broadly bilobed basally (Fig. 3D)
(sensu lato = Eupelicinae, Koebeliinae, Paraboloponinae, Penthimiinae, and Selenocephalinae)
Note: Acostemminae, Arrugadinae, Drakensbergeninae, Mukariinae, and Stegelytrinae, sensu Oman et al. (1990) will also key here.
64(63) Frontoclypeus in facial view at least 2× longer than wide; hind wing submarginal vein well developed (Neotropical)
64'. Frontoclypeus in facial view little or no longer than wide; hind wing with submarginal vein obsolete apically (Fig. 4N) (Holarctic)
Acknowledgments
I am grateful to D. Dmitriev, R. Rakitov, D. Takiya, J. Zahniser, and the participants in the Gainesville “Homoptera” workshop for helpful suggestions that greatly improved the keys; to the Russian Entomological Journal for permission to use Figs. 7A-N; and to G. A. Anufriev and A. F. Emeljanov for permission to use Figs. 3C-E, 4J-K, and 7O-P. Figures reproduced from Kramer (1950) and Oman (1949) are in the public domain. This work was supported in part by grants DEB 9978026 and DEB 0089671 from the National Science Foundation.
References Cited
Fig. 1.
Cicadoidea and Cercopoidea. A, Tettigarcta crinita (Tettigarctidae), Australia. B, Magicicada cassini (Cicadidae), Illinois. C, Paraphilaenus parallelus (Aphrophoridae), Kyrgyzstan. D, Clastoptera obtusa (Clastopteridae), Illinois. E, Hindola sp. (Machaerotidae), adult (top center) and tube constructed by nymph (lower left), Taiwan. F, Tomaspis sp. (Cercopidae), Mexico. G, spittle mass of Philaenus spumarius nymph. Photos by C. H. Dietrich.
Fig. 2.
Membracoidea. A, Myerslopia chilensis (Myerslopiidae), Chile. B, Hylaius oregonensis (Cicadellidae), Oregon. C, Flexamia grammica (Cicadellidae), Illinois. D, Llanquihuea sp. (Melizoderidae), Chile. E, Aetalion reticulatum (Aetalionidae), Peru. F, Heteronotus quadrinodosus (Membracidae), Mexico. Photos by C. H. Dietrich.
Fig. 3.
Leafhopper morphology. A, dorsal habitus. B, head, anterior view (face). C-D, apex of male abdomen, Deltocephalinae, lateral and ventral views, respectively. E, Typhlocybinae, male genital capsule, lateral view. F, apex of female abdomen, lateral view (vl = valvula, vlf = valvifer, s = sternite, t = tergite). Drawings A-B modified from Oman (1949), C-E modified from Anufriev & Emeljanov (1988), F from Kramer (1950).
Fig. 4.
Leafhopper head morphology. A-F, head, anterior view: A, Evacanthus (Evacanthini); B, Krisna (Krisnini); C, Tartessus (Tartessinae); D, Platyproctus (Adelungiini); E, Bathysmatophorus (Errhomenini); F, Thymbrus (Thymbrini). G-H, head and prothorax, lateral view: G, Cicadella (Cicadellini); H, Matsumurella (Athysanini). I-K, head, pronotum, mesonotum, and scutellum, dorsal view: I, Populicerus (Idiocerinae); J, Pediopsoides (Macropsinae); Oniella (Evacanthini). Drawings A-F original; G-K from Anufriev & Emeljanov (1988).
Fig. 5.
Morphology of cicadomorphan thorax (from Kramer 1950): A-C, Lepyronia (Aphrophoridae), dorsal, lateral, and ventral view (in A, pronotum removed to show mesonotum). D-F, same, Paraulacizes (Cicadellidae). G, Stictocephala (Membracidae), lateral view of meso- and metathorax. Abbreviations: acs = antecostal suture; acx = antecoxal area; aes = anepisternum; anp = anterior notal wing process; aw = prealar bridge; ax = axillary sclerite; ba = basalare; bst = basisternite; cx = coxa; cxp = pleural coxal process; epm = epimeron; es = episternum; fp = furcal pit; fst = furcasternite; kes = katepisternum; mr = meron of coxa; pbs = prebasisternite; pc = precosta; pls = pleural suture; pnp = posterior notal wing process; pnt = postnotum; pocx = postcoxal bridge; prnt = pronotum; psc = prescutum; pw = postalar bridge; pwg = pleural wing groove; sp = spiracle; st = sternite; tn = trochantin; tr = trochanter; twg = tergal wing groove
Fig. 6.
Leafhopper wings. A-G, forewing: A, Hortensia (Cicadellini); B, Errhomus (Errhomenini); C, Deltocephalus (Deltocephalini); D, Hamana (Scarini); E, Idiocerus (Idiocerinae); F, Typhlocyba (Typhlocybini); G, Jikradia (Coelidiinae). H-O, hind wing: H, Agallia (Agalliini); I, Macropsis (Macropsinae); J, Penestragania (Iassini); K, Typhlocyba (Typhlocybini); L, Protalebrella (Alebrini); M, Hymetta (Erythroneurini); N, Empoasca (Empoascini); O, Joruma (Jorumini). Drawings from Oman (1949).
Fig. 7.
Leafhopper leg morphology. A-E, apex of hind femur, dorsal view, showing variation in macrosetal formula: A, 2+2+1; B, 2+2+1; C, 2+1+1; D, 2+1; E, 2+1. F-J, right hind tibia, posterior view, except G and J, cross-section: F-G, Bathysmatophorus (Errhomenini); H, Bothrogonia (Cicadellini); I-J, Diplocolenus (Paralimnini). K-N, left front femur, anterior view: K, Doratura (Doraturini); L, Thagria (Thagriini); M, Alebra (Alebrini); N, Xestocephalus (Xestocephalini). O-P, hind tarsus, ventral view: O, Kybos (Empoascini); P, Balclutha (Balcluthini). Drawings A-N from Rakitov (1998), copyright Russian Entomological Journal, used with permission; O-P from Anufriev & Emeljanov (1988).
