Bioacoustics of Phasmagryllus

Description. Very small and delicate species ( Figs 8 A, 11A, B), resembling the unrelated Guianese genus Philippopsis Desutter-Grandcolas, 1992 in appearance and contrasted coloration, but still thinner. Very setose. Head very long and large, rounded. Vertex with many strong, widely separate setae. Fastigium very wide, not separate from the vertex ( Fig. 8 B, C), but slanting. Ocelli small, widely apart ( Fig. 8 C); distance between the median and one lateral ocellus smaller than the distance between the lateral ocelli; median ocellus in apical position. Eyes small, not protruding, well apart from each other ( Fig. 8 B). Maxillary palpi very elongate for the subfamily ( Figs 8 C, 9A); joint 3 well shorter than joint 4, which is smaller than joint 5; joint 5 concave dorsally, slightly widened toward apex, truncate obliquely over nearly half its length. Scapes slightly longer than wide ( Fig. 8 B). Pronotum ( Fig. 8 B) transverse, rounded; DD anterior margin slightly concave, posterior margin more concave: lateral lobes squared. Legs very thin but not very elongate ( Figs 8 A, 11A, B). TI with a inner tympanum, small, oval, obliterate; outer tympanum lacking; two ventral apical spurs. TII with two ventral apical spurs. TIII ( Fig. 8 D) with three inner and three outer apical spurs, the ventral the smallest and the dorsal the longest on both sides; inner dorsal spur the longest, about as long as half basitarsomere III. TIII with four pairs of subapical spurs, alternate, but almost aligned on one row; subapical spurs all small, growing longer toward TIII apex, except for the first subapical spur, the smallest; serrulation very sparse, almost lacking between subapical spurs. Tarsomeres long, the basitarsomere III very elongate. Abdomen as collapsed distally, short with narrow tergites. Cerci not particularly long. Coloration. Species dark brown with contrasted coloration ( Figs 8 B, 11A) on head, DD and antennae. Male. Metanotum with a pair of high median buds, flattened apically ( Fig. 8 F). Tergites two to five clearly convex along their distal margin, with concave areas near their anterior margins. FWs covering about half abdomen only ( Fig. 8 A), somewhat thickened; cell limits on FW surface very strongly marked ( Fig. 8 E); FW lateral margins almost parallel, the FWs not widened at the mirror level ( Fig. 8 E). Stridulatory apparatus complete, with functional file ( Fig. 9 B): harp wider than long, crossed by few parallel, oblique veins; mirror crossed by one transverse vein; chords occupying a large part of the FWs, the chord 1 widely apart from chords 2 and 3; one transverse cell under the mirror; apical field almost lacking. Lateral field well developed, but shorter than the dorsal field ( Fig. 8 H); few parallel, longitudinal veins ( Fig. 9 C). HWs bud like. Supra anal plate without strong bristles ( Fig. 8 I). Subgenital plate short, wide, truncate ( Fig. 8 G, H). Male genitalia. Fig. 9 . Small, asymmetrical. Pseudepiphallic sclerite transverse, H-shaped, prolonged lateroventrally by a sclerotization facing the rami ( Fig. 9 , v.ps.); connected to the rami by a thin, lateral sclerite; rami small and dejected ventrally. A pair of median rounded lobes, located distally to the pseudepiphallic sclerite; brisling with small spikes on inner face. A pair of disto-lateral huge pseudepiphallic structures, with a rounded and hollowed anterior part, and a bifid distal part; this bifid part with a short inner lobe and a spine-like outer lobe; left and right inner lobes facing each other; right spine-like lobe short, left one extremely elongate, prolonged far beyond subgenital distal margin ( Figs 9 D, F, 10). Pseudepiphallic parameres located in central position between these pseudepiphallic structures, plicated, with a ribbon-like sclerotization. Ectophallic fold very short, triangular and membranous. Ectophallic apodemes quite long; arc complete. No developped ectophallic dorsal valves. Ventral valves extremely reduced. Endophallic sclerite 3-pronged distally. Endophallic apodemes with a pair of short lamellae. A pair of half-circled transverse sclerites between the endophallic sclerite and the tip of ectophallic fold. Female. FWs very short and hardly overlapping ( Fig. 11 C); venation made of convex longitudinal veins only ( Fig. 9 G); lateral field very narrow ( Fig. 9 H). Subgenital plate transverse, distal margin bisinuate ( Fig. 9 I). Ovipositor flattened laterally; apex not widened and not ornemented ( Fig. 11 B, D). Female genitalia. In Phasmagryllus elegans Desutter-Grandcolas , n. sp. , copulatory papilla having the shape of a circular sclerite, which membranous center is prolonged by a short and wide, plicated duct ( Fig. 9 J). Phylogenetic relationships. By its morphology, and more specifically by its head shape (fastigium, ocelli), TIII shape, subapical spurs and serrulation, and male genitalia, Phasmagryllus Desutter-Grandcolas , n. gen. is close to other African Phaloriinae , even though its body shape and way of life resemble other non phaloriine Phalangopsidae such as Philippopsis or Phalangopsis Serville, 1831 in the Neotropical Region, or the African Phaeophilacris Walker, 1871 . These latter genera are straminicolous and cavicolous, foraging at night in the leaf litter, and hiding during the day in cavities at ground level such as burrows or hollow trees ( Desutter-Grandcolas 1992 , 1995 , pers. obs.). Convergence in body shape due to common habitat might have occurred between Phasmagryllus Desutter-Grandcolas , n. gen. on one hand, and other "truly" long-legged crickets such as Philippopsis , Phalangopsis , Phaeophilacris and the like.