Xanthogryllacris ralum, 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 : 94

Xanthogryllacris ralum sp. nov.

Figs. 31 A–C

Xanthogryllacris punctipennis Karny 1929d partim

Material examined. Holotype (male). Papua New Guinea: Bismarck Archipelago, Gazelle Peninsula , Ralum [Kokopo], 1.i.1896 — 31.xii.1897, leg. Fr. Dahl (Berlin ZMB).

Other specimens: same data as holotype— 1 female, 1 male (paratypes) (Berlin ZMB).

Diagnosis. X. p. ralum sp. nov. is very similar to X. p. dempwolffi ( Griffini, 1909b) that is only known from females. It differs by the shape of the female seventh abdominal sternite that has a short, roughly triangular and apically bifid process from full width of apical margin of sternite instead of an elongate, tongue-shaped process from midst of basal area of sternite. Males are characterized by the pair of stout, curved projections from apical area of ninth abdominal tergite that terminate into an acute tip and do not meet each other in midline. That resembles the situation in X. timoriensis (Karny, 1931) , but in the new species these projections are strongly curved mediad and terminating into an acute tip. The female of X. ralum differs from that of X. timoriensis by the seventh abdominal sternite in having a rather short apical projection with bifid tip instead of a stout projecting beam and the subgenital plate has the pair of apical lobes with angular instead of rounded tip. The male of X. punctipennis reported and described by Karny (1930b) from New Guinea Albatros Bivak has the male ninth abdominal tergite with rather long and sinuate projections that overlap in middle. That male certainly represents a different species.

Description. Head, body and legs uniformly yellowish to reddish brown. Ocelli distinct but small. Wings in all three specimens studied folded over body. Tegmen with a single media vein that is fused at base with radius, deviates somewhat before mid-length. Cubitus anterior divides before mid-length into two branches; cubitus posterior single branched throughout; with four anal veins, the last incomplete. Hind wings yellow with black marks along cross-veins.

Male. Ninth abdominal tergite globular, in apical half furrowed and apical margin wide rectangularly excised in middle. In male holotype on both sides of excision with a stout and curved tooth with subacute tip; teeth not reaching midline of tergite ( Figs. 31 A–B). In the second male the hind area of the ninth tergite appears to be somewhat collapsed thus that the excision looks triangular and the projections appear straight and their tips overlapping in midline. The latter male was figured by Karny (1929d fig. 43b). Subgenital plate little wider than long, furrowed in midline and with shortly bilobate apical margin; styli inserted at apico-lateral angles ( Fig. 31B ).

Female. Seventh abdominal sternite transverse with a stout bump in about middle of hind margin and with a broad triangular expansion from apico-dorsal surface of sternite. The expansion with concave ventral surface, terminating into a bifid tip and covering about basal half of subgenital plate. Subgenital plate elongate with regularly approaching lateral margins and with a distinct medial furrow; apical margin bi-triangular ( Fig. 31C ). Ovipositor curved, with lateral furrow and with a slight widening before tip, similar to that of X. p. dempwolffi.

Measurements (1 male, 1 female).—body w/wings: male 37, female 35; body w/o wings: male 25, female 27; pronotum: male 7.3, female 7; tegmen: male 27.5, female 26; hind femur: male 17.5, female 17.5; ovipositor (distorted): female ca 13 mm.

Etymology. Named after the type locality, noun in apposition.

Figures

FIGURE 31. Genus Xanthogryllacris: A–C, X. p. ralum sp. nov. male holotype (A–B) and female paratype (C); D–F, X. p. dempwolffi (Griffini, 1909) female holotype (D), female from New Britain (E–F); G–H, X. p. keyica (Karny, 1925) male; I–J, X. p. subrecta sp. nov. female holotype.—Male abdominal apex in apical (A, G) and ventral view (B, H), female seventh abdominal sternite and subgenital plate (C–E, I), female ovipositor (F, J).