Rentzgryllacris, Cadena-Castañeda, 2019

Cadena-Castañeda, Oscar J., 2019, A proposal towards classification of the Raspy Crickets (Orthoptera: Stenopelmatoidea: Gryllacrididae) with zoogeographical comments: An initial contribution to the higher classification of the Gryllacridines, Zootaxa 4605 (1), pp. 1-100 : 23-24

Rentzgryllacris n. gen.

Diagnosis: Medium size (20–30 mm) and body robust ( Fig. 62 ). Head with a medium size, ocelli little developed and ovoid, space between antennal cavities as wide as 1.5 times the wide of scape ( Fig. 63 ); fore coxa with a small and unarticulated spine, legs moderately long and robust, with five pairs of movable ventral spines on fore and middle tibiae; hind femora robust, with some ventral black spinules, hind tibia with six inners and seven outer. Tegmina well developed, ovoid and surpassing the abdomen tip; hind wings whit brown or black spots on intermediate veins. Last abdominal segment with small central cleavage dividing the hind margin in two lobules ventrally displaced, which in turn are armed with a hook near the tip; cylindrical cerci, three times as long as the subgenital plate ( Fig. 64 ). Subgenital plate with its styli located in the lateral margin near the tip; distal portion of the plate emarginate and with a central cleavage varyng in depth among the species ( Fig. 65 ). 9 th sternite of females with a membranous papilla varying in shape among the species. Female subgenital plate also rectangular, with a ventrally projected fold ( Fig. 66 ). Tip of the plate in females usually cleaved, thin and straight (very slightly curved upwards) ovipositor with rounded tip.

Included species: Type species: R. sechellensis ( Bolívar, 1895) n. comb. (Before in Prosopogryllacris ). R. fuliginata (Karny, 1928) n. status and R. silhouettensis Karny, 1937 n. status.

Etymology: Dedicated to David Rentz as a recognition to his great contributions to Australian Tettigonioidea and Stenopelmatoidea, plus typical termination— gryllacris common to genera of this family.

Comparison: This new genus differs from other African Gryllacridini by the following characters: Afronenias is a short-winged genus; From Stictogryllacris , Barombogryllacris and Griffinigryllacris n. gen., differs because these genera lack spots in the hind wings. This new genus is similar to Stictogryllacris in the emargination of the hind margin of the subgenital plate, but Rentzgryllacris n. gen., differs because the last tergite is ventrally projected with hooks located inside, unlike Stictogryllacris which does not have lobes on the 9th or 10th tergite and the hooks are close and curved upwards. The new genus also differs from Barombogryllacris because the wings surpass the abdomen tip and the ovipositor is not pointy nor does it have a strong upwards curvature. It is also different from Griffinigryllacris in not having an enlarged head and because of the characters of the male terminalia mentioned in the comparison with Stictogryllacris .

Rentzgryllacris n. gen., has hind wings with similar spots to some species of the Gryllacrae group, but it differs from the genera of that Group by its unique terminalia for males and females alike. Ovipositor is not curved nor with an obliquely truncated tip, which is a common feature of the genera included in the Group Gryllacrae. According to Karny (1937) (now valid) species included in Rentzgryllacris n. gen., were grouped in Prosopogryllacris , differing in the characters of the terminalia of the male mentioned above: male of Prosopogryllacris have two small protuberances (usually non-sclerotized), which are lacking in Rentzgryllacris n. gen.

Distribution: Seychelles Archipelago.

Comments: Subspecies included in Prosopogryllacris sechellensis ( Bolivar, 1895) , are here considered as valid, which differ among themselves by the structure of male terminalia and body color pattern.

Figures

FIGURES 62–66. Rentzgryllacris n. gen. Male habitus of R. fuliginata n. comb., frons, male terminalia in lateral view, male subgenital plate and basal section of female ovipositor (basal plate, subgenital plate and last sternite in lateral view). Figures 64 to 66 redraw from Karny, 1932.