Vescelia sepilokensis Tan, Gorochov, Japir & Chung, 2019

Tan, Ming Kai, Gorochov, Andrei V., Wahab, Rodzay Bin Haji Abdul, Japir, Razy & Chung, Arthur Y. C., 2019, New taxa of crickets (Orthoptera: Grylloidea: Gryllinae, Phaloriinae and Pteroplistinae) from northern Borneo (Belait and Sandakan), Zootaxa 4661 (1), pp. 101-117 : 106-108

Vescelia sepilokensis Tan, Gorochov, Japir & Chung , new species

( Figs. 4 , 5 )

Material examined. Holotype (male, SDK.19.24), East Malaysia, Sandakan District , Sepilok, Rainforest Discovery Centre, dipterocarp forest, N5.87524, E117.94215, 36.3±6.0 m, 9 January 2019, 1940 hours, near stream, coll. M.K. Tan, R. Japir, M. Binti & J.L. Yukang ( FRC).

Diagnosis. The new species differs from all known species of Vescelia with known males by the presence of additional movable elongate rachial ectoparameres (ec) or ventral sclerite in the male genitalia which are located on membranous lateral folds under lateral parts of rachis, and by the distal parts of rachis having lateral lobules directed aside.

Comparison with congeners. The new species is somewhat similar to Vescelia pieli (Chopard, 1939) ( China, Japan, Vietnam), V. mulu Gorochov, 2014 from Sarawak and V. variegata (Chopard, 1937) from Palawan in the rachis having a pair of distal lobes. However, the new species is additionally distinguished from the first and second species by the ectoparameres which are much not reaching apices of distal epiphallic processes, and from the second and third one, by the rachis with less deep posteromedian notch. From V. picta (Chopard, 1932) from Kalimantan, the new species differs in the same characters as in Diagnosis as well as in the male genitalia longer, epiphallic distal processes not curved in profile, ectoparameres thinner and longer, and rachis distinctly bifurcated. Vescelia infumata Stål, 1877 from the Philippines is impossible for comparison, as it is known only from female.

Description. Male. General appearance typical of this genus ( Figs 4A, 4B ). Head with frontal rostrum between antennal cavities approximately as wide as scapus, pubescent with strong long setae; eyes large, globular in dorsal view but elongated in lateral view; maxillary palpus long and slender, with apical segment longest, and with subapical segment shorter than third segment (apical segment only slightly widened apically); ocelli rounded; median ocellus surrounded by strong long setae. Pronotal disc pubescent, moderately transverse (1.3 times as wide as long), widening posteriorly; anterior margin of disc straight, with a row of strong setae developed also along anterior edge of pronotal lateral lobe; posterior margin of disc angularly convex, without strong setae ( Fig. 4A ). Pronotal lobe also pubescent, slightly longer than wide, with anteroventral corner almost 90º, and with ventral margin straight ( Fig. 4B ). Legs densely pubescent, especially the ventral margins; fore tibia with a large, oblong inner tympanum, distinctly immersed; outer tympanum of this tibia oval and smaller, not immersed ( Figs. 4C, 4D ); hind tibiae with 4 pairs of long movable dorsal spines (long and slender, with apex slightly hooked), not very numerous small immovable spinules between them, and 6 long spurs (=apical spines); hind barsitarsus with two rows of small dorsal spines. Tegmen reaching middle of cercus, very finely pubescent, with 6 harp veins in dorsal field, with mirror about as long as wide and having 2 dividing veins (anterior vein straight; posterior one shorter and curved; Fig. 4A ); lateral tegminal field wide, with 17 branches of Sc and 13 cross-veins between R and M ( Fig. 4B ); R and M diverging gently in basal half and strongly converging towards the apex; area between these veins widest at its distal third; hind wings distinctly exposed behind tegmina, reaching apex of cercus. Subgenital plate rectangular (longer than wide), with apical part truncate, with median ventral groove, and with shallow ventral depression on distal half. Genitalia ( Figs. 4 E–G, 5): epiphallus with posterolateral epiphallic lobes (p.ep) long and slender, surpassing apices of ectoparameres; with a pair of medial ventral epiphallic lobes (m.ep); rachis (ra) large, elongate, plate-like, strongly narrowing near bifurcated apical part (with narrow and not very deep posteromedian notch), and with rather large lateral lobules on this part directed aside, at the base with a forked sclerite underneath the epiphallus; rachial ectoparameres (ec) or ventral sclerite located on membranous lateral folds under lateral parts of rachis and movable, elongated, converging towards each other posteriorly, with lateral margins parallel, and with apical part truncated but having apical lobule on inner margin (this lobule stout and with obtuse apex); endoparameres (en) in shape of arcuate ribbons located near (along) anterior edge of rachis, fused with each other in median part, having elongate and rather narrow posterior arms as well as moderately long anterior apodemes; formula (f) elongated and weakly sclerotized, with a pair of bean-shaped lateral lamellae in anterior part, with elongate and not very narrow posterior part, and without apodeme; rami (r) in dorsal view straight, not fused together by the anterior ends.

Female. Unknown.

Colouration. Body brown with following marks: head with dark patterns on vertex, with median and lateral ocelli white, and with mouthparts light brown; fore and middle femora light brown with 2 brown bands (one band fainter and located near middle; second one located near knee); fore and middle tibiae with 2 whitish bands (one just below tympanum, and one near apex); hind femur pale with four brown bands, knee pale brown, hind tibiae with five dark brown bands (some of them situated between spurs); tegminal lateral field with membranes between R and M light yellowish brown, and with membranes between Sc branches transparent; abdomen with cerci light brown.

Measurements (in mm). BL = 12.8; HL = 1.6; PL = 3.2; PW = 4.3; TL = 15.4; TW = 6.0; HWL = 21.1; HFL = 12.6; HTL = 12.6.

Etymology. The species is named after the type locality, Sepilok in Sandakan.

Figures

FIGURE 4. Vescelia sepilokensis Tan, Gorochov, Japir & Chung, sp. nov. male holotype: dorsal (A) and lateral (B) habitus; outer (C) and inner (D) tympana; genitalia in dorsal (E), ventral (F) and lateral (G) views.

FIGURE 5. Vescelia sepilokensis Tan, Gorochov, Japir & Chung, sp. nov. male genitalia (posterior end): Schematic diagram in dorsal (A) and ventral (B) views.