Derbachile aschei Emeljanov et Shcherbakov, 2020

Emeljanov, A. F. & Shcherbakov, D. E., 2020, The first Mesozoic Derbidae (Homoptera: Fulgoroidea) from Cretaceous Burmese amber, Russian Entomological Journal 29 (3), pp. 237-246 : 240

Derbachile aschei Emeljanov et Shcherbakov , sp.n.

Figs 11–20, 25, 26.

MATERIAL. Holotype PIN 5608 /123a, ♂, head and thorax dorsally eaten by some arthropod scavenger; paratypes PIN: 5608/ 123b, male (?), in same amber piece as holotype, oxidized, antennae detached; 5608/129, sex unknown, fore legs malformed, most of head, hind legs and abdomen eaten away; 5608/130, female — Burmese amber, Hukawng Valley, Kachin State, Myanmar; mid-Cretaceous (probably Albian–Cenomanian).

DIAGNOSIS. Wings fuscous with darker shade along vein apices and pale at and near crossveins; body and legs fuscous; median carina of mesonotum incomplete; hind tibia with 3 lateral teeth.

DESCRIPTION. Tegmen 2.9 (paratype 5608/130) – 3.6 mm long (paratype 5608/129), elongate, much widened distally, 2.3:1; membrane fuscous, finely transversely corrugate; veins darker, apical vein sections margined with darker shade; stigmal cell brown; pale: ScRA1, RA2a, RA2b, ir and RP near it, 2r-m, ima, MP2 base, 2m-cu, CuA1 from 2m-cu to icua, icua and CuA2 shortly beyond it, postclaval crossvein, and truncate claval apex. Anterior margin almost straight near base and shallowly convex beyond; apical margin broadly rounded. Costal vein turning flat, ecarinate distad of ScR fork. C and ambient vein with minute sensory pits from base to apex of tegmen. ScR fork slightly distad of, and CuA fork more distad of, union of claval veins. Nodal r-m distal to, or sometimes level with, nodal m-cu. MA fork much closer to nodal r-m than to 2r-m. Medial cell long and narrow, about as large as cell anterodistal or cell distal to it. Crossvein on clavus between CuP and middle of Pcu. Claval furrow continued beyond truncate claval apex; CuP+Pcu+1A running close to posterior margin slightly beyond postclaval crossvein. Hind wing very large, almost 0.9 as long as tegmen, and very broad, 1.7:1, apex slightly not reaching apex of tegmen in repose; membrane pale fuscous, finely wrinkled; apical vein sections margined with darker shade, veins and coupling lobe brown, medial and claval folds pale. Costal margin biconvex, coupling lobe in concavity before wing midlength. ScRA apex proximad of level of M fork. M fork 1.3 times as long as CuA1 fork. Body 2.3 (paratype 5608/130) – 2.9 mm long (paratype 5608/123b); body and appendages various shades of brown. Head 1/2 as wide as pronotum; eyes large, ovoid, emarginate below; head and coryphe arcuately excavate posteriorly; posterior angles of coryphe close to eye midlength. Coryphe narrow trapezoidal, anteriorly less than 1/5 head width and less than 1/2 as wide as long in middle, slightly depressed between high lateral carinae markedly converging anteriorly, median carina obsolete; coryphe steeply curved into metope. Metope tricarinate, narrow and depressed between high lateral carinae, more than twice widened ventrally. Lateral ocellus anterior to eye. Scape rather short, not produced, pedicel 2.5 as long as scape, enlarged and slightly flattened, scape + pedicel 3/4 as long as head width. Pedicel covered with cuticular denticles, with many plaque organs. Subantennal ridge absent. Postclypeus tricarinate, strongly narrowed towards unicarinate, laterally flattened anteclypeus. Rostrum reaching hind coxae, apical segment dark, 4 times as long as wide. Pronotum 0.9 as wide as mesonotum, 0.4 as long in middle as wide, inverted V-shaped, lateral margins acute, posterior margin sinuate medially; strongly elevated triangular tricarinate disc as wide as long in middle, almost 0.4 pronotum width. Mesonotum with nearly diamond-shaped disc, lateral carinae of disc obsolete, converging anteriorly, weak median carina in anterior part. Legs slender, femora and tibiae carinate. Hind tarsus 2/3 as long as tibia, tarsomere I longer than II+III; tibia and tarsomeres I and II markedly widened at apices; tibia with minute lateral tooth near base and two larger ones before 1/3 and 2/3 length, and 11 apical teeth in uneven pecten; tarsomere I with 9, II with 6 apical teeth. Claws slender. Male genital block rather large, anal tube long, with lateral lobes, styles long, upcurved. Female genital block subtriangular in ventral aspect.

REMARKS. The specimens assigned to this species share the same general structure and colour pattern, but show significant size variation, indicating that they may belong to more than one closely related species, distinguishable only by the characters of male genitalia, as in the genus Cedusa Fowler, 1904 .

ETYMOLOGY. Named in honour of Dr Manfred Asche, an eminent entomologist, specialist on Delphacidae and other Fulgoroidea.