Diagnosis. Platphalonia magdalenae is a small tan moth with a pale reddish-brown transverse fascia. The diagnostic features are the tan ground color, the slightly reflective nature of the fore wing scales, the curved reddish-brown postmedial fascia that extends from the inner margin to the costa, and the brownish-gray hind wings. As is typical with many species of Cochylina, the generic assignment of P. magdalenae cannot be determined from the external appearance of the adult moth. Superficially, P. magdalenae might be confused with several species, in several genera, of Cochylina. An examination of the male genitalia is required for positive assignment to a genus. Within the genus Platphalonia, the only other described species from California is P. campicolana (Walsingham, 1879). The fore wing of P. campicolana is cream-white, the reddish fascia extends from the inner margin to mid-wing, the postmedian fascia does not reach the costa, and the fringe is black. The fore wing of P. magdalenae is tan and the fringe is not black. Platphalonia albertae, P. californica, P. dangi, P. lavana, P. luxata, P. parvimaculana, and P. plicana, also occur in the Nearctic Ecozone. The width of the mesal process of the transtilla narrows subapically in P. albertae; whereas in P. magdalenae it is not narrowed subapically. The acutely pointed apices of the bifurcate terminus of the mesal process of the transtilla are distinctly pointed laterally in P. californica; whereas in P. magdalenae are not pointed laterally. The fore wing of P. dangi is dirty-white with an oblique dark colored fascia extending from just before the apex to outer margin 2/3 from the tornus; the fore wing of P. magdalenae is tan without an oblique dark fascia. The ground color of the fore wing of P. lavana is dirty-white, the fore wing has an excurved subterminal gray fascia extending from just before the apex to the tornus, and the fringe is black; in contrast, the ground color of the fore wing of P. magdalenae is tan without a subterminal fascia, and the fringe is concolorous. The ductus bursae of P. luxata is ringed with sclerotization at the junction with the corpus bursae; the ductus bursae of P. magdalenae is encircled with linear rugosities at the junction with the corpus bursae. The ground color of the fore wing of P. plicana is dirty-white, the subterminal area contains a patch of contrasting dark-brown scales, the terminal line is black, the fringe is contrastingly dark brown, and the hind wing is gray; the fore wing of P. magdalenae is tan, there is no patch of dark-brown scales in the subterminal area, the terminal line and fringe are not contrastingly dark, and the hind wing is dark fuscous.

Description. Adult male (Fig. 1). Head: Front smooth, tan, with scattered tan-tipped orange scales; vertex pale-tan, with scattered dark-tan scales, smooth, posterior margin with scales erect. Labial palpus porrect, segments 1 and 2 mixed with tan and chamois-colored scales, lateral and mesal surfaces with scales appressed, dorsal and ventral surfaces weakly tufted, segment 3 directed anteriorly, with light tan, appressed scales. Antenna with dorsal surface scaled, tan, ventral surface naked with setae numerous, length = width of antennal segment. Thorax: Dorsum tan and chamois-color, smoothly scaled; underside with scales appressed, shining white and silver. Fore-leg femur with scales appressed, dorsal surface tan, with scattered brown and orange scales, ventral surface dirty-white, scales of tibia, femur and tarsi appressed, dorsal surface tan, scattered brown scales, ventral surface dirty-white. Mid-leg scales appressed, femur dirty-white, tibia, femur, and tarsi dorsal surface tan, scattered light-brown scales, ventral surface dirty-white. Hind-leg scales appressed, dirty-white. Forewing length 3.9–5.5 mm, mean 4.7 mm, n = 18. Upper surface of forewing reflective white (appears tan), anterior one half of basal 1/3 narrowly salmon, basal 1/3 of costa dark brown, distal 2/3 of costa tan; posterior one half of basal area chamois color; subbasal fascia angled outward from inner margin, chamois color; postmedial fascia angled outward from inner margin, bent at cell towards costa, pale horn color, at costa mixed with brown and salmon, brown scales at bend; subterminal fascia angled from cell to just before apex, pale horn color, subterminal area below apex with small patch of brown scales; fringe pale horn color mixed with salmon and brown scales; underside inner margin reflective white scales, area over cell brown-tipped reflective white scales, basal one half of costa brown, outer one half salmon; fringe reflective white. Hindwing with tan-gray tipped reflective white scales, base lighter, inner angle darker, fringe concolorous, reflective; underside reflective white, tan-gray tipped scales numerous, inconspicuous; fringe concolorous. Abdomen: Dorsum scales appressed, reflective silver-tan; underside scales appressed, mixed tan and pale gray. Genitalia (Fig. 3) with tegumen wide, prominent, apex flattened, suture mesially; uncus absent; socii appressed, membranous, broad, lightly sclerotized apically; transtilla robust, directed ventrally, mesally bent, mesal process drawn out, apex robust, bifurcate, each arm drawn to a blunt point, apex with tiny teeth laterally; juxta broad, elliptical; saccus obscure; valva simple, elongate, curved dorsally, with scattered setae apically, costa sclerotized; saccular region not produced, weakly sclerotized, with scattered setae; phallus (Fig. 4) longer than wide, gradually narrowing apically, bent 30° at 1/3 length; cornuti poorly defined, obscure, lightly sclerotized.

Adult female (Fig. 2). Head and thorax: Essential as described for male. Forewing length 5.0–5.3 mm, mean 5.1 mm, n = 3. Hindwing with frenulum of one, two, or three bristles, asymmetrical. Abdomen: Genitalia (Fig. 5) with papilla analis membranous, narrow, setose; posterior apophysis extending to anterior margin of 8th segment; anterior apophysis divided basally, extending to anterior end of ductus bursae; antrum weakly sclerotized; ductus bursae lightly sclerotized posteriorly, mesally membranous, anteriorly sclerotized, fluted and widening at junction with corpus bursae; corpus bursae short, round, membranous, densely covered with spicules in patches; signa absent.

Holotype. Adult male, pinned with labels as follows: “Legit Val Albu, Tulare Co/California, Rt. 43 @ Allensworth, 2 V 2011″ “HOLOTYPE USNM Platphalonia magdalenaeMetzler & Albu” [red handwritten label] (USNM).

Paratypes. 20 m, 3 f: same data as Holotype. Depositories: VA, MSU, UCB, USNM.

Systematics. This new species is placed in the genus Platphalonia based on comparison of the female genitalia with the holotype of Saphenista mystica Razowski & Becker, 1983, which is the type species of Platphalonia. Our analysis was confirmed by Józef Razowski (in litt., 2012).

Etymology. The species is named after Magdalena Albu, who, as the wife of the second author, lovingly and dutifully followed and helped with his entomological excesses. The name is in the genitive case.

Distribution and biology. The diurnal nectaring behavior of adult Cochylina is unusual, and we call attention to it here with the idea that the behavior could be present, and as yet unobserved, in other species of Cochylina.

Platphalonia magdalenae occurs in the Central Valley of California. Its distribution outside Tulare County is unknown. Nothing is known about its life history, however, an association with Centromadia pungens ssp. pungens is reasonably inferred.

The adults of P. magdalenae were collected in early May. The habitat is in the intensively farmed Central Valley, along California State Route 43, in the vicinity of Allensworth, CA at 60 m elevation (Fig. 7). The plant upon which the adults were found, Centromadia pungens ssp. pungens (Fig. 8), is found in the U.S. from Washington south through Oregon, California, Nevada, and southern Arizona (USDA 2012). The plant is not recorded from Canada, and the Mexican distribution is unknown. The plant's distribution in California (Baldwin et al. 2012) is extensive at lower elevations, from the Sierra Nevada foothills to the coast. It is not recorded from the eastern deserts of the state. In Tulare County it occurs abundantly in disturbed areas, along roads and rail road tracks. It has a long blooming period, from April to September.

Remarks. Some specimens are slightly darker. They have scattered dark-brown scales on the head, the palpi, and an increased number of dark-brown scales on the legs.