Gymnogryllus egorovi Gorochov, 2022

Gorochov, A. V., 2022, New and little known taxa of the genera Gymnogryllus and Macrogryllus (Orthoptera: Gryllidae: Gryllinae) from Indo-Malayan and Papuan Regions, Proceedings of the Zoological Institute of the Russian Academy of Sciences 326 (1), pp. 3-13 : 4-6

Gymnogryllus egorovi Gorochov sp. nov.

( Figs 1–7 , 18 )

Etymology. This species is named after its collector, A.M. Egorov.

Type material. Holotype – male, INDONESIA: Maluku Utara Prov., Halmahera I., eastern coast not far from Veda Town , forest on hill, 8–11 May 2019, A. Egorov.

Description. Male (holotype). Body medium-sized for this genus, shining, with following coloration: head intensively brown with light brown ocelli, three proximal segments of each antenna, indistinct areas on epicranium along clypeal suture and on lower halves of genae behind eyes, with greyish eyes, with dark brown a pair of transverse stripes on epicranium under eyes and a pair of small spots in dorsolateral corners of clypeus, with greyish brown labrum and rest of each antenna, and with more or less light brown rest of mouthparts (except for small and narrow blackish marks on maxillae but not on their palpi; Figs 1, 2 ); pronotum intensively brown but with poorly distinct reddish brown spots on disc, with also poorly distinct dark brown areas on lateral parts and with almost light brown band on each lateral lobe along anterior and middle thirds of its ventral edge (this edge rather dark); legs uniformly light brown but with numerous and almost indistinct yellowish/brownish oblique lines on lateral surface of hind femur, and with darkened denticles on hind basitarsus as well as distal portions of all spines (and spurs) and small marks in places of femorotibial articulations; tegmina with greyish brown dorsal field having dark brown dasal area and semitransparent membranes in stridulatory apparatus ( Fig. 1 ), and with light brown lateral field having brown band along dorsal edge (this band located between Sc and M and additionally occupying upper halves of membranes between Sc branches in distal third of this field; rest membranes between branches of Sc in distal half of this field almost semitransparent); other tergites more or less brown; anal plate and paraprocts greyish brown; venter of body light brown with light greyish brown genital plate having a pair of slightly darker and poorly distinct lateroproximal areas; cerci also light greyish brown, with somewhat light- er bases. Structure of body almost typical of Gymnogryllus : rostrum between antennal cavities almost twice as wide as scape ( Fig. 2 ); pronotum hardly wider than head, barely narrowing to posterior part which slightly widening to pterothorax ( Fig. 1 ); legs with moderately large and oval outer tympanum (its length almost equal to width of fore tibia in tympanal region, and approximately 2.5 times as great as width of this tympanum), with much smaller inner oval tympanum (outer tympanum almost 2.5 times as long and almost 1.5 times as wide as inner tympanum), with normal apical spurs and five pairs of articulated dorsal spines on hind tibia, with four pairs of large dorsal denticles on hind basitarsus, and with inner spur of this basitarsus reaching distal third of apical segment of hind tarsus and almost twice as long as outer spur of this basitarsus ( Fig. 1 ). However, tegmina not typical of this genus, because their oblique veins numerous (6–7), two of them distinctly S-shaped, chords and diagonal vein rather long and less curved, mirror primitive in structure (rather large, almost rectangular) but with short and incomplete dividing vein, apical area moderately long (with six branches) and reaching apex of anal plate ( Fig. 1 ); lateral tegminal field with 9–10 branches of Sc (seven costal of them starting from base of this field, slightly oblique and from almost straight to somewhat arcuate; others starting from distal half of Sc stem, mostly shorter and from slightly S-shaped to clearly arcuate) and with moderately numerous but poorly distinct crossveins; hind wings strongly shortened, much shorter than tegmina. Genitalia and spermatophore ( Figs 4–7 ) also clearly distinguished from those of other congeners: epiphallus ( Figs 4, 6 ) transverse, with very short and wide posteromedian lobe having a pair of small lobules directed backwards and slightly aside, with a pair of short but narrower posterolateral lobes, with a pair of longer and rath- er wide anterolateral lobes having narrowly angular anteromedial projections, and with very wide and moderately deep as well as more or less rounded anteromedian notch; ectoparamere ( Figs 5 , 18 ) rather narrow and long (longer than epiphallus), with partly semisclerotized widened posterior portion having almost angular apical part and connected with narrowly triangular mesal lobe by very thin and rather short sclerotized ribbon, with longer and sclerotized proximal portion, with mesal lobe having narrow and long ribbon running backwards and almost reaching apex of strong but not very long posterodorsal sclerite (process); endoparamere rather short, with large dorsal apodeme, without ventral apodeme, and with somewhat thinner (almost hooked) part connected endoparamere with ectoparamere ( Figs 4, 6 ); virga rather short, moderately wide in middle part and with narrower but strong distal portion having acute apical part ( Fig. 5 ); sacculus medium-sized, semicircular in profile, without sclerotized semitube along its anterior and dorsal edges ( Fig. 6 ); rami very long, strongly curved in anterior portions and almost fused with each other anteriorly ( Figs 4, 5 ); spermatophore as in Fig. 7 .

Variation. Inner tympanum of left fore leg almost 1.5 times as long and wide as that of right fore leg (i.e. one inner tympanum somewhat smaller than in holotype, but other one slightly larger than in holotype); tegmina with 5–6 oblique veins in dorsal field and with less curved dividing vein in mirror ( Fig. 3 ); hind tibia with four outer and five inner dorsal articulated spines; hind basitarsus with five inner and 3–4 outer dorsal denticles.

Female unknown.

Length (mm). Body 25–26; pronotum 5.6–5.8; tegmen 17–18; hind femur 17.5–18; hind tibia 11.4– 11.7; hind basitarsus 4.6–4.8.

Comparison. The new species is clearly distinguished from all other congeners by the more numerous and partly S-shaped oblique veins in the male dorsal tegminal field, by the more primitive structure of the male tegminal mirror, and by the characteristic both the epiphallic shape and the ectoparameral structure in the male genitalia.

Figures

Figs 1–7. Gymnogryllus egorovi sp. nov., male, holotype (1, 2, 4–7) and paratype (3): 1 – body from above; 2 – head in front; 3 – right tegmen; 4–6 – genitalia from above (4), from below (5) and from side (6); spermatophore from side (7).

Figs 18–33. Structures of male genitalia (schematically), left ectoparamere from below (18–27) and epiphallic apex from behind (28–33): 18 – Gymnogryllus egorovi sp. nov.; 19 – G. vietnamensis mada subsp. nov.; 20 – Phonarellus minor (Chop.); 21 – Tarbinskiellus portentosus (Drury); 22 – Macrogryllus ephippium ephippium (Sauss.); 23 – M. e. vespertinus Gor.; 24 – M. canorus sp. nov.; 25 – M. bicolor Chop.; 26 – Megalogryllus (Megalogryllus) excellens Gor.; 27 – M. (Gigantogryllus) neotropicus (Gor.); 28 – G. v. mada subsp. nov.; 29 – G. v. longidens Gor.; 30 – G. v. vietnamensis Gor.; 31 – G. sylvestris Gor.; 32 – G. obscurus Gor.; 33 – G. equinus Gor. [20, 21, 26, 27 – after Gorochov (2019); 29–33 – after Gorochov (2011).]