Bioacoustics of Sinodecma acuta

Male. Body comparatively large for the tribe Meconematini . Fastigium verticis long, protruding forwards, exceeding edge of antennal sockets, stout, slightly compressed, apex acute, with indistinct longitudinal sulcus. Eyes globular, obviously protruding forwards. First segment of antennae stout. Apical segment of maxillary palpi as long as subapical one, apex slightly enlarged. Pronotum short, posterior transverse sulcus distinct, metazona slightly raised; anterior margin straight, posterior margin widely rounded; lateral lobe long as high, humeral sinus distinct. Procoxa with one spine, tibial tympana open on internal and external sides, long-oval, protibiae with 5 spines on internal and external sides of ventral margin. Mesotibiae with 5 spines on both sides of ventral margin. Posttibia with 20–21 spines on internal and external sides of dorsal margin, all femora without spines on ventral margins, genicular lobe blunt. Thoracic auditory comparatively large. Tegmina developed, surpassing apices of postfemora, stridulatory area distinct, terminalia roundedly angular. Hind wings as long as tegmina. Tenth abdominal tergite comparatively narrow, middle area of posterior margin convex, elongated afterwards, centre slightly protruding. Genitalia sclerotized, bearing a pair of lamella-like structure, finger-shaped in lateral view, with some small teeth on apical and subapical edge, titillators paired about half length of cerci, clubbed, bent upwards, apices bluntly rounded, with a triangular lobe on basal area. Cerci thin, long, apices enlarged, curved inwards, with a small dorsal lobe near middle area, and a short inner lobe on basal area. Subgenital plate with base broad, apical part narrowing, centre of posterior margin slightly concave. Styli short and small. Female. Similar to male except as follows: fastigium verticis compressed laterally, apex slightly blunt, longitudinal sulcus distinct. Lateral margins of tenth abdominal tergite protruding posteriorly. Cerci long conical, apical 1/ 3 thin, apices rounded. Ovipositor long, basal part stout, comparatively curved upward, dorsal and ventral margins smooth, apices acute. Subgenital plate short and broad, basal half soft, concave upward, posterior margin bluntly rounded. Colour. Body light yellow (probably yellowish green in life). Apical half of tegmina yellowish green, posterior margin yellowish brown. Dorsal margin of head with a longitudinal yellowish brown stripe, reaching apex of fastigium verticis. Pronotum also with a longitudinal light yellowish brown stripe, posterior area widened. In female, yellow longitudinal stripe on centre of back area of head and disc slightly narrower than that of male. Measurements (mm). Body: 313.5, Ƥ13.5; pronotum: 34.2, Ƥ3.9; tegmina: 322.0, Ƥ23.0; postfemora: 311.0, Ƥ11.5; ovipositor: 11.5.