Bioacoustics of Thyestetha nitida

Description. Lectotype , male. Length. Pronotum + elytra: 5.3 mm . Color. Antenna, tarsi and rostrum ferruginous; head, prothorax and legs ferruginous to black; elytra and remaining ventral surface dark red. Habitus elongate-subovate, in dorsal view slightly constricted between pronotum and elytra ( Fig. 6 ); profile dorsally constricted between pronotum and elytron ( Fig. 15 ). Rostrum 5.5 X as long as wide at base, with small scattered scales. Head. Vertex with small punctures, medially strongly punctate, few white scales near eye. Prothorax 1.2 X wider than long; postocular lobe weakly developed; disc densely punctate with small punctures (except basal row of coarse punctures), interstices larger in basal half, smooth, polished; sides densely punctate with small punctures, posterior margin with white scales; rostral canal and marginal carinae with overlapping cream-colored scales. Elytra 1.1 X longer than wide; sides rounded; apex distinctly extended, jointly rounded; punctures of striae 1–9 distinctly impressed from base to apex; interstices 1– 3 X wider than diameter of punctures, interstices between punctures of stria 9 ca. 0.5 X diameter of puncture. Metanepisternum 2.8 X wider than high. Thoracic venter. Meso- and metaventrite strongly squamose; metaventrite submedially behind mesocoxa with pair of conspicuous protrusions. Pro- and mesocoxa densely punctate, squamose; metacoxa subglabrous; trochanter with sparse, coarse punctures containing scales. Distance between mesocoxae subequal to width of mesocoxa. Legs. Profemur moderately punctate; meso- and metafemur laterally sparser, scales broader dorsally and ventrally; dorsal squamose line of metafemur dense, conspicuous; anteroventral ridges conspicuous. Metafemur in apical third with distinctly protruding posteroventral ridge. Abdomen. Ventrites 1 to 4 entirely squamose; ventrite 5 basally with scales, remainder setose. Terminalia. Aedeagus ( Figs. 47, 48 ). Apex moderately curved ventrad, sides sinuate, converging; lateral orificial sclerites elongate, inner portion 3 X longer than outer portion; anterior median orificial sclerite simple between 2nd and 3rd fold (as in Fig. 36 ). Dorsal and ventral contour of transfer apparatus straight; anterior and posterior ends weakly curved ventrad; in dorsal view fusiform. Sclerotized part of ventral membrane extending proximad 0.69 X length of aedeagal body from insertion of apodemes. Selected female specimen. Same as holotype except: Rostrum 6.50 X longer than wide. Prothorax 1.06 X longer than wide. Elytra as long as wide; apex less extended, slightly more slender. Metafemur without concavity basal to stridulatory patch, posteroventral ridges slightly protruding. Terminalia. Hemisternites of ovipositor 10.75 X longer than wide. Tergite VII ( Fig. 60 ) 2.23 X longer than wide. Tergite VIII ( Fig. 59 ) 1.93 X longer than wide. Bursal sclerite ( Fig.65 ) at insertion of spermathecal duct weakly sclerotized. Intraspecific variation. Length, males 3.2–5.4 mm (n=5, x = 4.8 mm ± 0,9 mm), females 3.6–5.2 mm (n=13, x = 4.5 mm ± 0.5 mm ) in females. Elytra dark or light ferruginous. Prothorax. Anterior 1/4 of disc punctate with small punctures, remainder with minute punctures (except for row of coarse punctures along base) in most specimen. Pronotum and elytra relatively weakly punctate in one small female from the Papuan Gulf. Elytral apex sometimes slightly emarginate.