Parabaisochrysa xingkei, Lu & Wang & Ohl & Liu, 2018

Lu, Xiumei, Wang, Bo, Ohl, Michael & Liu, Xingyue, 2018, The first green lacewing (Insecta: Neuroptera: Chrysopidae) from the mid- Cretaceous amber of Myanmar, Zootaxa 4399 (4), pp. 563-570 : 565-567

Parabaisochrysa xingkei sp. nov.

( Figs. 1–2 )

Diagnosis. Same as for the genus.

Description. Preserved part (apex of abdomen unpreserved) of body 4.51 mm long; preserved part of right antenna 2.05 mm long; preserved part of left antenna 1.37 mm long; head 0.85 mm long and 1.47 mm wide; width between compound eyes 0.60 mm; pronotum 0.64 mm long and 0.84 mm wide; meso- and metathorax 1.76 mm long and 1.26 mm wide; forewing 9.10 mm long and 4.76 mm wide; hind wing 8.32 mm long and 2.44 mm wide (measured based on left wings).

Head with vertex distinctly domed and ovoid. Compound eyes large and semi-globular. Antennae filiform, partly preserved; scape stout, subcylindrical; pedicel much thinner and shorter than scape, but slightly thicker than remaining flagellomeres.

Prothorax slightly narrower and shorter than head. Mesothorax robust; prescutum paired, nearly as long as scutellum; scutum nearly paired, with each part subtriangular; scutellum subtriangular, slightly convex posteriad. Metathorax obscure.

Forewing ovoid, transparent. Costal space broad sub-proximally but strongly narrowed distad, with 11 simple crossveins; pterostigma narrowly elongate, slightly darkened. ScA absent; ScP entering costal margin at distal 1/4; subcostal space very narrow, with one proximal scp-ra crossvein present slightly distad origin of RP+MA. RA long, entering wing margin near wing apex, sparsely branched distad, with nine veinlets, proximal one of which is bifurcated; RA space with 15 crossveins; origin of RP+MA nearly at same level of proximal ending of im cell, being perpendicular to RP; RP with 10 branches, and most of them bifurcated distad except for two simple branches anteriad last branch. Three gradate series of crossveins present, complete and nearly parallel to each other; Psm almost not developed; Psc confidently identified. MA diverging from RP near origin of RP+MA, simple. MP diverging into MP1 and MP2 near base of wing, forming an acute angle; MP1 simple, MP2 zig-zagged, distally forked. 1im cell narrow, elongated (about five times as long as wide), proximally acutely tapering; 2im cell slightly shorter than 1im cell. Two m-cu crossveins present; 1m-cu short, approximating diverging point of CuA and CuP; 2m-cu slightly longer, located at distal position of 1im cell. CuA and CuP diverging near base of wing; CuA and CuP respectively bifurcated distally; two cua-cup crossveins present. A short cup-a1 crossvein present proximally. A1 simple, slightly arched; A2 simple, much more curved than A1; A3 rather short and simple.

Hind wing much narrower than forewing; costal space narrow, about twice width of subcostal space, with about nine simple crossveins. Subcostal space with no crossvein detected; ScP entering wing margin at distal 1/5 of wing. RA long, distinctly curving posteriad, terminating at wing apex, distally with nine veinlets, most of which are simple except proximal two ones bifurcated; 14 radial crossveins present; RP+MA originated quite near base of wing. RP with 8 branches, and most of them bifurcated distad. Three gradate series of crossveins present. MP proximally diverging into MP1 and MP2, but MP1 partially fused with RP+MA, with proximal section of MP1 short and crossvein-like; MP2 long, distally bifurcated. CuA distally bifurcated, connected with MP2 by two crossveins; two crossveins present between CuA and CuP; CuP short, proximally fused with A1 and A2.

Legs poorly preserved; left foreleg slender, densely hairy; tarsus 5-segmented, almost as long as tibia, tarsomere 1 much longer than each of rest tarsomeres, tarsomeres 2–5 almost equal in length; pretarsal claws simple, slender and long, with sharp tips; arolium invisible.

Abdomen stout, curved ventrally; genital segments not preserved.

Type material. Holotype: NIGP167964: Amber piece with a partly preserved adult of Parabaisochrysa xingkei sp. nov., along with a midge and a beetle. It is polished in form of a triangular prism cabochon, with length×width about 2.3× 0.8 mm, height about 0.7 mm. The preservation condition of the specimen is poor as the wings are strongly twisted along and close to different surfaces of amber piece that is a triangular prism cabochon. Therefore, it is hard to clearly observe the wings from each one side of view, and the complete wings have to be viewed by turning the amber piece.

Etymology. The new species is dedicated to Prof. Xingke Yang, who made considerable contribution on the taxonomy of Chrysopidae , particularly on the green lacewing fauna of China.

Figures

FIGURE1. Photographs of Parabaisochrysaxingkei gen.et sp.nov.,holotype.A.Habitus,lateral view; B. Head,lateral view; C. Proximal part of left forewing; D. Distal part of left forewing; E. Right hind wing. Arrow in B indicates antenna. Scale bar: 1.0 mm.

FIGURE 2. Parabaisochrysa xingkei gen. et sp. nov., holotype.A. Drawing of left forewing with reconstruction; B. Drawing of right forewing; C. Drawing of left hind wing; D. Drawing of right hind wing. Scale bar: 1.0 mm.