Amphibologryllacris Karny, 1937

Hugel, Sylvain, 2009, Gryllacrididae and Tettigoniidae (Insecta, Orthoptera, Ensifera) from Espiritu Santo, Vanuatu, Zoosystema 31 (3), pp. 525-576 : 533

Genus Amphibologryllacris Karny, 1937

Amphibologryllacris Karny, 1937: 134 .

TYPE SPECIES. — Gryllacris dubia Le Guillou, 1841 .

DISTRIBUTION. — see Karny (1930a).

DIAGNOSIS. — Nannogryllacris and Amphibologryllacris are distinguished from all other gryllacridid genera by the following characters: Head: not particularly wide; frons smooth or indistinctly punctuated; frons/genae limit not forming a sharp prominent carina. Pronotum: not with a deep furrow (unlike in Epacra ). Wings: FW and HW well developed; transverse veinlets neither darkened nor lined with dark. FW only one and half as long as TIII. FW M either free on FW base ( Fig. 1 ), or emerging from Rs; M simple or with one bifurcation; Cu usually furcating on 3 to 4 branches, in this case at least 5 A are following, the last two often with a common root. HW transparent or light smoked, without strikingly black transverse veinlets; Rs + M with simple common root emerging from R, or basally with a common root with Cu. Legs: TI and TII with 2 rows of 4 well-developed ventral subapical spurs (in addition to the 2 apical spurs); TII dorsally unarmed or with at most 1 dorsal posterior apical spur; FIII neither particularly long nor slender ( Fig. 2C, D ; elongated in Epacra ); TIII unmodified, not with 1 or 2 long spear-shaped spines (i.e. unmovable) on the inner margin. External genitalia: neither male anal segment nor subgenitalis stretched backwards into a hull shape; male cerci usually not much longer than styli; on T IX, neither blunt nor spiny protrusion; appendices cerciferae at least developed in some species; male subgenital plate without a small protrusion on the middle, between the styli; ovipositor well sclerotized, not rolled in dead specimens; females of most species with SGP preceding sternite usually modified (bulging and/or with protrusion(s), such modifications are lacking in Epacra ).

In addition to the above-mentioned character combination, Amphibologryllacris is characterized by the following. Size: body length: 15.5-31 mm; FIII: 10.2-16; FW: 16-25 mm. Colour: light brown, some species and/or specimens with black elements (face, occiput, pronotum, knees, legs, abdominal tergites/sternites); FW veins colour usually strikingly light compared to the darker FW cells. Prosternum unarmed; mesosternum lateral lobes forming distinct ventral spines pointing ventrally; metasternum lateral lobes with smaller spines pointing ventrally backwards ( Fig. 1 ). Cerci not reduced, longer than styli.

AMPHIBOLOGRYLLACRIS POSITION RELATIVELY

TO NANNOGRYLLACRIS AND EPACRA

Until now, only two gryllacridid genera were considered as bearing spiny lobes on mesosternum and metasternum: Epacra and Afroepacra Griffini, 1911 . On museum specimens, this obvious character is often hidden by the legs, and has therefore not been seen by previous authors (suggesting that other described genera might share this character too). Usually, most gryllacridid genera are badly defined by very few (often one) discrete characters supposedly derived, and this has not been cladistically tested. In spite of the character paucity, Amphibologryllacris , Nannogryllacris and Epacra appear as clearly distinct genera, but in the absence of a comprehensive cladistic analysis of the subfamily, stating affinities between genera would be too speculative.

Figures

FIG. 1. — Amphibologryllacris Karny, 1937, sternum: A, A. macrocera (Walker, 1869), left side view, note the pointing lateral lobes (arrows); B, C, A. butmasi n. sp., left side (B) and ventral (C) views. Abbreviations: see text. Scale bars: 1 mm.

FIG. 2. — Amphibologryllacris Karny, 1937 from Espiritu Santo: A, C, E, G, A. butmasi n. sp.; B, D, F, H, A. macrocera (Walker, 1869); A, B, ovipositor,right side view;C, D, left femur III side view;E, F, face;G, H, ventral views of male subgenital plate showing intraspecific variation (the four specimens on the right side are alcohol preserved). Scale bars: A-D, 10 mm; E-H, 1 mm.