Strivicia davidi, SHCHERBAKOV, 2022

SHCHERBAKOV, DMITRY E., 2022, A new genus of Ipsviciidae (Hemiptera, Cicadomorpha) with a tegminal strigil from the Triassic of Madygen, Palaeoentomology 5 (5), pp. 434-438 : 435

Strivicia davidi sp. nov.

urn:lsid:zoobank.org:act:A093D1D3-16B8-4F13-8A29-570E7C3EDD58

( Fig. 2 )

Material. Holotype PIN 3288 /316±, finely preserved left tegmen (clavus missing) and paratype PIN 3288 /388±, right tegmen (clavus except apex missing) from southwestern Madygen area; paratype PIN 2785 /2432 (negative impression), complete left tegmen from Dzhailoucho ; Madygen (35 km WSW Isfara), Leilek District, Batken Region, Kyrgyzstan.

Etymology. In honour of our colleague David Grimaldi, for his excellent studies of fossil insects.

Diagnosis. As for genus.

Locality and horizon. Madygen Formation, Ladinian– Carnian, Middle or Upper Triassic.

Description. Tegmen length 4.2–4.4 mm, width 1.6– 1.8 mm, elongate (length/width ratio 2.5–2.6:1), as seen in the holotype and paratype from the SW Madygen area. The paratype from Dzhailoucho is stretched transversely (its surface punctures are transformed into short subtransverse wrinkles) and appears much shorter and broader, but in fact it is of nearly the same size (length 3.4 mm, width 1.8 mm, √LW 2.5 mm) as the two former (√LW 2.6–2.8 mm). Tegmen widest just before midlength, costal margin arched there, nearly straight more proximally and arched at base. Precostal carina wider proximally, deflected dorsad; hypocostal carina narrow; basicostal projection low; bSc large arch; costal fracture transverse; costal area moderately wide, its part between costal fracture and dSc sloped and occupied with oblong strigil. Basal cell short, triangular, closed with short M+CuA anastomosis. R(+dSc) stem convex, short, oblique; dSc continuing its direction, convex, sigmoidal, moderately long (1/5–1/3 tegmen length, much longer than R stem), joining margin before or at (Dzhailoucho paratype) tegmen midlength. R distal to dSc longitudinal, with 3 anterior branches, bent at origin of third branch; apex of tegmen at narrow apical cell between R and M. M and CuA stems arched in opposite directions, enclosing lanceolate medial area, CuA arched close to CuP. Branches of CuA and M forming common posterior pecten with 4 terminations, CuA 1 apparently fused to posterior M branch. Crossvein r-m short, much more distal than free basal section of CuA 1 (looking like m-cu). Clavus occupying 2/3 tegmen length, claval veins (Pcu and 1A) united at 2/3 clavus length, their common stalk entering commissural margin much before claval apex. Upper surface of tegmen covered with rasp-like punctures, coarser and denser in proximal half, especially on basicostal piece, finer and sparser in distal half. Stridulatory area on underside of tegmen 1.1 × 0.23 mm, consisting of more than 40 oblique rows of microtrichia; rows 4 times more dense at base of strigil (14 per 100 μm) than in its distal part (3.5 per 100 μm); microtrichia (except near strigil base) transformed into short ridgelets up to 15 μm long, oriented across rows, i. e. almost longitudinally. Large pale ocellate spot margined with dark in widest part of medial area, similar smaller spot more distally in radial area, and probably one more at 1A; vein terminations margined with dark, CuA 2 with dark mark, dark specks and spots (more developed in Dzhailoucho paratype) along veins and in anterior area; ground colour pale fuscous.

Figures

FIGURE 2. Strivicia davidi gen. et sp. nov. A–D, Holotype, left tegmen, A, B, Counterpart, whole tegmen. C, D, Part (images flipped). C, Proximal part of tegmen with strigil. D, Proximal half of strigil. E, F, Paratype PIN 3288/388, right tegmen (part). G, H, Paratype PIN 2785/2432, left tegmen (counterpart). A, F, G, Photographs. B–E, H, SEM (BSE). I, Line drawing of tegmen (based on the holotype and paratypes; dashed line, costal fracture; dotted contour, strigil). Scale bars = 1 mm (A, B, E–I), 0.2 mm (C, D).