Tetraconcha bicolor Gorochov, 2023

Gorochov, A. V., 2023, New taxa of the subfamily Phaneropterinae (Orthoptera: Tettigoniidae) from Africa: the tribes Otiaphysini and Preussiini, Caucasian Entomological Bulletin (Caucas. entomol. bull.) 19 (1), pp. 23-30 : 26

Tetraconcha bicolor Gorochov , sp. n.

( Figs 15–21 )

Material. Holotype, ♂ ( ZIN): Uganda, southwestern region, Bushenyi Distr., environs of Kalinzu Nature Reserve , ~ 1000 m, primary forest, at light, 23– 28.02.2020 (A. V. Gorochov) . Paratypes: 2♂ ( ZIN), same data as for holotype .

Description. Male (holotype). Body distinctly smaller than in Drepanophyllum irisovi sp. n. Colouration yellowish with following pattern: epicranium rose with reddish brown spots on dorsum (a pair of spots near eyes and median spot on upper rostral tubercle and near it) and spot on each gena, yellowish ocelli and vertical stripe under each eye as well as small spot on ventromedial edge of each antennal cavity and triangular median spot near clypeus; antenna reddish brown to brown with yellowish base of scape and very small marks on middle and distal parts of flagellum; mouthparts with rose most part of palpi, tinge on mandibles, dorsal spot on clypeus and dorsal half of labrum; pronotum with numerous rose dots on disc and on lateral lobes; tegmina with brownish rose most part of lateral field between costal area and anal edge, brownish grey some cell membranes in basal part of yellowish costal area ( Fig. 17 ), greyish (semitransparent) areas between R and dorsal field near its stridulatory apparatus as well as in dorsal field behind mirror (part of latter area short in left tegmen but almost trice larger in right tegmen; Figs 15, 16 ), brown to dark brown large spot on stridulatory apparatus of left tegmen (this spot including most part of stridulatory vein and of nearest vein as well as part of mirror membrane; Fig. 15 ), reddish brown basal area in both tegmina and stridulatory vein in right tegmen, and almost transparent mirror and small area near plectrum in latter tegmen ( Fig. 16 ); hind wing transparent with brownish rose venation and thickened apical part ( Fig. 18 ); legs rose to light reddish brown with yellowish proximal half of hind femur and ventral parts of three proximal segments of all tarsi. Upper rostral tubercle strongly truncated distally (lateral ocelli located practically at apex of this tubercle), with not narrowed anterior part having distinct median groove, without groove on dorsum, but with dorsal edges of lateral ocelli slightly and roundly projected upwards. Pronotum with slight median groove and V-shaped groove on disc, with posterior edge of disc barely rounded, and with lateral lobes rounded ventrally and posteroventrally but having rather deep and moderately wide (roundly angular) humeral notches. Tegmina long, with rather narrow and rounded distal parts, with stridulatory apparatus as in Figs 15 and 16 , and with stridulatory vein of left tegmen regularly arcuate and having two lateral stridulatory teeth which larger and clearly sparser than others ( Fig. 21 ); hind wing distinctly protruding beyond tegminal apices, with costal part as in Fig. 18 . Last abdominal tergite with barely but widely concave posteromedian edge; epiproct rather wide and short, almost rectangular and with distal part more or less straight and slightly curved upwards ( Fig. 20 ); cercus rather long, moderately arcuate and with thin distal half having heavily sclerotized (darkened) small apical part which truncated at apex and with very small medial denticle ( Figs 19, 20 ); genital plate moderately elongate, with rather wide proximal two thirds and narrow distal third having rather deep posteromedian notch and a pair of finger-like lobules around it ( Fig. 20 ); genitalia membranous.

Variability. Paratypes with slightly lighter anterior part of head (this part almost completely or only clypeus and mandibles uniformly yellowish), sometimes without rose dots on pronotum and abdomen, and sometimes with completely darkened mirror of left tegmen and partly darkened mirror of right tegmen.

Female unknown.

Length (in mm). Body 15–17; body with wings 42–44; pronotum 4.8–5; tegmina 32.5–34; hind femora 22.5–23.5.

Comparison. ffle new species is most similar to T. banzyvilliana Griffini, 1909 ( Zaire) but distinguished by the costal tegminal area almost completely yellowish (vs this area is very dark in the proximal half and yellowish in the distal half), the rest of the lateral tegminal field lighter (vs it is dark brown to blackish), the presence of a rather large greyish (semitransparent) area in the latter field near its stridulatory apparatus (vs this tegminal region with dark membranes), and clearly longer both the widened part of the dorsal field of the left tegmen and its mirror (compare Fig. 15 and the photograph of T. banzyvilliana holotype in Cigliano et al. [2022]). From all other congeners incluging “smaragdina-group” [ Massa, 2017, 2021], T. bicolor sp. n. differs in the following combination of characters: tegminal colouration is bicolourous; left tegmen has a darker spot on its stridulatory apparatus and a normally developed (not almost indistinct or strongly modified) mirror; stridulatory vein of this tegmen is shorter or longer as well as regularly arcuate (not S-shaped or almost broken) and with only two lateral teeth which are distinctly larger and sparser than other teeth.

Etymology. fflis species name is the Latin word “bicolor” (two-colour, dichrome) due to the characteristic colouration of the tegmina.

Figures

Figs 15–28. Species of the genus Tetraconcha, males, details of structure. 15–21 – T. bicolor sp. n.; 22–28 – T. unicolor sp. n. 15, 25 – stridulatory apparatus of left tegmen; 16, 26 – stridulatory apparatus of right tegmen; 17, 22 – left tegmen; 18, 23 – costal part of left hind wing; 19, 24 – cercal apex from above; 20, 27 – abdominal apex from above and slightly behind; 21, 28 – stridulatory vein of left tegmen ventrally. Рис. 15–28. ВиΑы роΑа Tetraconcha, самцы, ΑетаΛи строения. 15–21 – T. bicolor sp. n.; 22–28 – T. unicolor sp. n. 15, 25 – стриΑуΛяционный аппарат Λевого наΑкрыΛья; 16, 26 – стриΑуΛяционный аппарат правого наΑкрыΛья; 17, 22 – Λевое наΑкрыΛье; 18, 23 – костаΛьная часть Λевого заΑнего крыΛа; 19, 24 – вершина церка сверху; 20, 27 – вершина брюшка сверху и сΛегка сзаΑи; 21, 28 – стриΑуΛяционная жиΛка Λевого наΑкрыΛья вентраΛьно.