Psilargus anufrievi Shcherbakov, 2020

Shcherbakov, D. E., 2020, The earliest fully brachypterous auchenorrhynchan from Cretaceous Burmese amber (Homoptera: Fulgoroidea: Jubisentidae), Russian Entomological Journal 29 (1), pp. 6-11 : 9-10

Psilargus anufrievi Shcherbakov , sp.n.

Figs 1–8 .

MATERIAL. Holotype brachypterous female PIN 5608 /106 — Burmese amber, Hukawng Valley, Kachin State, Myanmar; mid-Cretaceous (Albian–Cenomanian).

DESCRIPTION. Body 3.6 mm long, compact, ovoid, somewhat compressed laterally, especially abdomen. Dorsal outline serrated in profile due to carina at head apex, raised or upcurved posterior edges of body segments, and transverse ridges on tegmina and abdominal tergites I– V. Dorsum without conspicuous longitudinal carinae or setae, finely longitudinally wrinkled, with one patch of transverse wrinkles in anterolateral part of tegmen. Head brown, dorsum unevenly suffused with brown, legs dark brown with pale spot under fore knee, sternites I– VI pale brown, sternite VII and ovipositor darker.

Head 1.3 mm wide, 1.9 mm high. Coryphe transverse, 3.5 times as wide as long, rising towards angulate anterior margin, with median carina. Eumetope 1.8 times as long as wide, gradually narrowed ventrally, twice as wide dorsally as ventrally, slightly tectiform in cross section, with median carina. Boundary of eumetope and coryphe arched in facial view, formed by single high carina faced dorsad. Each half of eumetope with about 15 sensory pits in two irregular rows, medial row of larger pits reaching level of antennae, lateral row of smaller pits restricted to dorsal half of eumetope. Clypeus as long as eumetope, with deeply arched median crest and oblique loroclypeal sutures not reaching it. Eyes large, ovoid. Antenna short, scape extremely short dorsally and slightly longer anteroventrally; pedicel ovoid, 1.5 as long as wide, with at least 12 sensory plaque organs. Rostrum 1.1 mm long, slender, reaching base of abdomen, with apical segment longer than wide.

Pronotum nearly 2.5 times as wide as long, with median carina; anterior margin trapezoidal, projecting forwards between eyes and somewhat overlapping coryphe; lateral margin very short, posterior margin W-shaped with shallow median incision; each half with nearly 15 sensory pits in two rows, anterior row of smaller pits and posterior row of larger pits with few smaller pits displaced posteriorly and forming rudimentary third row; pectoral lobe with 7 pits. Mesonotum subtriangular with apex truncate and upcurved, 1.7 times as long as wide, each half with 3 sensory pits anterolaterally; mesopleura small. Tegmina strongly brachypterous, truncate, wider than long, covering only thorax (abdominal tergite I free), not meeting with their commissural margins, without traces of veins, with narrow epipleuron separated by lateral carina, and transverse posterior submarginal ridge aligned with apex of mesonotum; metapleura large, anepisternum very dark, convex.

Coxae, femora and tibiae fringed along ribs with dark, erect, long and shorter setae. Coxae long, fore and mid coxae about as long as thorax height above them; fore coxae with outer edge foliaceous. Fore legs 3.8 mm long. Fore femora and tibiae foliaceous with outer margin more convex than inner margin; tarsi of subequal segments, 1 st segment flattened laterally and highest, 3 rd slender and longest. Mid legs 2.6 mm long, slender, femora flattened, tibiae narrow foliaceous, tarsi slender with 3 rd segment longest. Hind legs 3.4 mm long. Hind trochanter largely membranous, with dark hook-like sclerotization along anteroventral side. Hind tibia quadrilateral, slightly curved, twisted distally, without lateral teeth, with fin-like lateral lobe on posterodorsal rib subapically. Apices of hind tibia and 1–2 nd tarsomeres swallow-tailed with apical pectens of numerous setigerous teeth. Tibial pecten arched in apical view, all 8 teeth with long subapical setae. 1 st tarsomere longest with pecten semicircular in apical view, of 10 teeth, outermost teeth with shortened subapical setae. 2 nd tarsomere shortest, compressed laterally, inserted into 1st, with pecten deeply V-shaped in apical and dorsal views, of 14 teeth, both outermost teeth widened, without subapical setae. 3 rd tarsomere slender. Claws simple, slender, strongly curved and tapered to apices; arolium well developed, wide, much shorter than claws.

Abdomen 2.6 mm long, tergites and sternites deeply arched or almost V-shaped. Tergites I– VI short with raised posterior margin, I– V also with anterior submarginal ridge and in each half with 1(2) submedian sensory pit and lateral row of several pits (I — 1, II — 4, III — 5, IV — 6, V — 3); tergite VI without pits. Spiracles visible as dark dots on membranous laterotergites near anterolateral angles of tergites I– V; laterotergite VI without spiracle, not separated from sternite. Sternites I– VI shorter than tergites. Tergites VII– VIII apparently somewhat reduced and/or hidden between membranous folds; sternite VII much longer, more convex and sclerotized than preceding, with shallow submedian posterior incisions. Segment IX (pygophore) elongate, tapered caudally, with anterior margin deeply incised, posterior submarginal ridge and lateral row of 5 sensory pits beyond it; ventral side concave, housing ovipositor. Ovipositor well developed, 1.2 mm long, occupying half of abdomen length. 3rd valvulae broad, lancet-shaped, consisting of outer subcylindrical rachis downcurved and tapered to acutely rounded apex, and lip-like blades with arched edges directed ventromedially, meeting along midline and leaving only bases of cutting inner valvulae exposed. Segment X (anal tube) as long as wide; dorsal side roof-shaped with median carina; lateral carinae with rectangular acuminate posterior angles; apical side with paired drop-shaped epiprocts and short anal style.

ETYMOLOGY. The species is dedicated to the memory of a Russian expert in Auchenorrhyncha, Georgy A. Anufriev (1943–2017).

Acknowledgements. I am deeply indebted to Alexey Bashkuev ( PIN) for attracting my attention to this fossil, Alexander Emeljanov (Zoological Institute RAS, St.- Petersburg) and Roman Rakitov ( PIN) for valuable suggestions and comments on the manuscript. The study was supported by the RFBR project 18-04-00322.

Figures

Figs 1–8. Psilargus anufrievi gen. et sp.n., holotype female, Burmese amber: 1 — habitus, anterolateral view; 2 — habitus, lateral view; 3 — antenna, anterior view; 4 — distal parts of hind legs (arrows — tibial lobe and apical pectens); 5 — head, frontal view; 6 — head and thorax, anterolateral view (arrows — margin of tegmen); 7 — abdomen, lateral view; 8 — head and thorax, dorsal view. Scale bars: 1–2 — 1 mm; 3–4 — 0.2 mm; 5–8 — 0.5 mm. Рис. 1–8. Psilargus anufrievi gen. et sp.n., голотип, самка, бирманский Янтарь: 1 — обЩий вид, спереди-сбоку; 2 — обЩий вид, сбоку; 3 — антенна, спереди; 4 — верШины Задних ног (стрелки — лопасть на голени и гребни); 5 — голова, спереди; 6 — голова и грудь, спереди-сбоку (стрелки — край Элитры); 7 — брЮШко, сбоку; 8 — голова и грудь, сверху. Длина масШтабной линейки: 1– 2 — 1 мм; 3–4 — 0,2 мм; 5–8 — 0,5 мм.