Larnaca (Larnaca) nigricornis, 2018

Ingrisch, Sigfrid, 2018, New taxa and records of Gryllacrididae (Orthoptera, Stenopelmatoidea) from South East Asia and New Guinea with a key to the genera, Zootaxa 4510 (1), pp. 1-278 : 204-205

Larnaca (Larnaca) nigricornis sp. nov.

Figs. 71 A–C, 72A–D, 101E

Material examined. Holotype (male): Vietnam: Hoa Binh Prov., Cuc Phuong National Park , (20°19'N, 105°36'30''E), 19–23.vii.2011, leg. J. Constant & J. Bresseel (I.G. 31.933)—(Brussels RBINS)

Other specimens studied: Vietnam: same data as holotype, 1 male (paratype) (Brussels RBINS); Hoa Binh Prov., Ngo Luong Nat. Res., (20°26'16''N, 105°20'15''E), 25–30.vii.2016, leg. J. Constant & J. Bresseel (I.G.: 33.282 GTI project)— 2 males (paratypes) (Brussels RBINS) .

Diagnosis. The new species is similar to L. eugenii ( Griffini, 1914b) . It differs by the projections of the male ninth abdominal tergite, which are more strongly curved or twisted just behind base and then regularly curved ( Fig. 72 A– D), while in L. eugenii they are less strongly and regularly curved throughout. The male subgenital plate, which has a transverse fold in both species, has the apical margin between bases of styli somewhat more widely notched and in apical view markedly widened in L. nigricornis sp. nov. ( Fig. 72B, D ), while in L. eugenii the apical notch is relatively narrower and the apical margin not markedly widened. The tegmina are wider in L. nigricornis then in L. eugenii , especially in anterior half of tegmen. Coloration is similar between both taxa with following exceptions: the black spot between lateral and medial ocelli does not include the antennal scrobae, the scapus is not black except at both ends, the mandibles have the basal area light in L. nigricornis , while antennal scrobae, scapus and mandibles are fully black in L. eugenii . The pronotum has a black rim in both species but in L. nigricornis it does not include the anterior margin that is of light color instead there is a marked pair of black spots behind margin but not in midline while in L. eugenii there is a wider black spot behind fore margin including midline or in the male from Tay Yen Tu that has most of the black spots on disc reduced there is still a small black spot behind fore margin in midline.

Description. Rather short and stout, medium sized species. Head: Face ovoid, nearly smooth or matt; fastigium verticis wider than scapus, suture between fastigium verticis and fastigium frontis weak; ocelli distinct; subocular furrow strongly expressed. Abdominal tergites two and three without stridulatory pegs, rarely with few remnant pegs.

Wings just covering abdomen or little shorter, not reaching hind knees. Tegmen ovoid; apart from the two subcostal veins, with eight or nine full length veins in nearly equal distance from each other, plus a shorter vein before hind margin. In holotype on the left tegmen the second of the post-subcostal veins divides behind basal third into two branches, on the right tegmen the second and the third post-subcostal veins divide before apical third and in mid-length respectively; cubitus anterior with uni-branched base, this vein forked into two veins (media and cubitus anterior?) between end of basal third and middle of tegmen on both tegmina; cubitus posterior undivided, free throughout; with 6 anal veins, the first two branches fused or closely approached at base, the last branch weak. In a paratype with nine full length post-subcostal veins the second of the post-subcostal veins (RS?) appears behind basal third as a fusion of cross-veins from the first and third veins (R and MA?).

Legs: Fore coxa with a spine at fore margin; fore and mid femora unarmed; fore and mid tibiae with four pairs of large ventral spines and one pair of smaller ventral spurs; hind femur with 6–10 external and 9–15 internal spines on ventral margins; hind tibia with spaced spines on both dorsal margins, ventral margins with one preapical spine; with 3 apical spurs on both sides.

Coloration. General color medium to dark brown with black marks; vertex dark reddish brown; pronotum yellow brown with black ornaments and black hind and lateral margins; anterior margin of general color ( Fig. 71A ). Legs brown with black strokes and spots; especially tibiae on external side with a longitudinal black band, on hind tibia that band sends lateral branches to the dorsal spines. Face dark reddish brown, anterior area of fastigium verticis, fastigium frontis, antennal scrobae, antennae, apical halves of mandibles and labrum black; ocelli whitish yellow; clypeus bordered with black but very lateral margins white, in middle yellow and red; maxillary palpi light yellow. Tegmen orange brown, at tip semi-transparent white, very base black, veins dark reddish brown to black; hind wing semi-transparent white, main veins black, cross-veins brown.

Male. Eighth abdominal tergite prolonged and slightly globular. Ninth abdominal tergite globular with a distinct furrow and then divided in midline; in apical area swollen on both sides of midline, at ventro-internal angle prolonged into a long spiniform process, in apical area compressed and with finely granular surface, tip subacute ( Fig. 72 A–D). Tenth abdominal tergite largely reduced. Epiproct triangular with wide medial furrow; paraproctes form extended plates from base of cerci. Subgenital plate at base flat, then bent ventrad and afterwards bent dorsad; posterior area in apical view flat; apical margin in middle with two short conical projections, in between roundly excised; styli curved and distinctly conical, inserted in posterior area of lateral margins ( Fig. 72B, D ).

Female (only known from photographs, Fig. 101E ). General habitus and coloration as in male. Ovipositor curved with simple, subobtuse tip.

Variation. The specimens at hand come from nearby localities. Those from Ngo Luong agree with those from Cuc Phuong in size; wings and color pattern are nearly identical, but in specimens from Ngo Luong of slightly darker basic color. Regarding the male abdominal appendages, the specimens from Ngo Luong have the projection of the ninth abdominal tergite rather narrow, in apical view straight but little curved towards the body, not stout and somewhat down-curved as in the specimens from Cuc Phuong. The apical area of the subgenital plate is straight, pointing behind, not up-bent as in the latter. Those differences are regarded as individual variation and may partly also result from deformation during conservation.

Measurements (4 males).—body w/wings: 32–36; body w/o wings: 28–36; pronotum: 7.0–7.5; tegmen: 20.5– 23.0; tegmen width: 8.5–9.5; hind femur: 15.5–18.0; antenna: 100 mm.

Figures

FIGURE 71. Genus Larnaca: A–C, L. nigricornis sp. nov. male holotype (A–B) and paratype (C); D–G, L. eugenii (Griffini, 1914) male holotype (D–E) and male from Tay Yen Tu (F–G); H–I, L. tenuis sp. nov. female holotype; J–K, L. samkos sp. nov. female holotype; L–N, L. subaptera sp. nov. male holotype; O–P, L. squamiptera sp. nov. female holotype; Q, L. larnacoides (Karny, 1937) female in Karny collection (not a type).—Habitus dorsal view (A, D, F, H, K, L, O), do. lateral view (M, Q), face (B–C, E, G, I–J, N, P).—Scales 10 mm (habitus), 5 mm (face), not all images to scale.

FIGURE 72. Genus Larnaca: A–D, L. nigricornis sp. nov. male holotype (A–B) and paratype (C–D); E–H, L. eugenii (Griffini, 1914) holotype (E) and male from Tay Yen Tu (F–H); I–L, L. subaptera sp. nov. holotype.—Male abdominal apex in dorso-apical and apical view (A–G, I), ventral view (H, K) and oblique lateral view (J), stridulatory pegs on second and third abdominal tergites, front is right (L).

FIGURE 101. A, Capnogryllacris (C.) sakaerat toxica ssp. nov. female paratype; B, Furcilarnaca salit sp. nov. male holotype; C, Ultragryllacris triangula sp. nov. male; D, Ultragryllacris pulchra nan ssp. nov. male holotype; E, Larnaca (L.) nigricornis sp. nov. female; F, Ocellarnaca angulata Gorochov, 2004 female; G, Larnaca (Larnaca) squamiptera sp. nov. female holotype; H, Siamgryllacris rufa sp. nov. female. Photos E–F by Jérome Constant.