Bioacoustics of Trichophallus gracilis

Diagnosis. ( female ): Apical projections of the female subgenital plate narrow, not widening posteriorly, just reaching but not surpassing the subbasal, ventral projections of the dorsal ovipositor valves; basal-lateral extensions of subgenital plate wider than length of central basal area of subgenital plate. Description of female holotype according to Karny (1907) translated from Latin: Fastigium verticis conical, straight, not surpassing the first antennal segment, dorsal margin not sulcate. Pronotum with a fine doublet dorsal band in mid-line, otherwise unicoloured. Lateral lobes unicoloured. Tegmina long, fuscous punctate. Anterior femur with 3–5 very small spines at posterior margin and 4 spines at anterior margin; mid femur with 5 anterior and 2 very tiny posterior spines; hind femur with many spines at anterior and 3–4 spines at posterior margin. Hind knee lobes bi-spinose. Ovipositor short, narrow, curved with acute end, in mid-length widened. It differs from T. concolor by its gracile figure, the pale color, the less numerous spines on the femora, and the shorter ovipositor. Measurements of holotype : body 22, pronotum 5, tegmen 31, hind femur 17, ovipositor 8.5 mm . Description of female characters based on this study. The female subgenital plate has a short but broad transverse basal sclerite that is in the type somewhat retracted and thus hidden below the preceding sternite, has the surface concavely vaulted and is on both sides prolonged into a down-curved, flattened plate. From hind margin of the more central area arises a pair of narrow, rounded, and curved sclerites that reach about to behind beginning or mid-length of the oval, basal projections of the ventral ovipositor valves without touching them ( Fig. 2 ). Two other females (from Astrolabe Bay and from Wanuma) show identical structures of the subgenital plate although they are less shrunk. Also the shape of the ovipositor of these three females agrees with the type of T. gracilis . The corresponding male of these females is thus chosen as typical for T. gracilis . Diagnosis (male). Males can be recognised by the shape of the elongate and little curved cerci that carry in subbasal area a hump with a short, acute spine at tip. Diagnostic are also the male titillators that have the sclerotised area truncate in about mid-length and continue as membranous tubes toward conical end. Male. Stridulatory file with about 133 teeth. Tenth abdominal tergite at apex with a convex excision, at both sides of excision with an obtuse lobe pointing mediad. Epiproct with lateral margins convergent in basal area only, otherwise parallel or slightly diverging posteriorly; dorsal surface with a deep pit, followed by a faint or distinct medial furrow; apex in dorsal view bilobate, slightly excised in middle; apex in apical view with a pair of acute ventral projections. Paraprocts with a roughly triangular, obtuse swelling at internal margin. Cerci long, in dorsal view moderately curved throughout, slightly compressed in apical half, in lateral view slightly sinuate, mainly curved in basal area; internal margin with a compressed triangular internal tooth in basal quarter that has a spine at tip; apex of cercus obtuse. Subgenital plate roundly excised at apex; narrow styli of about same length with excised area or shorter. Titillators band-shaped with only the basal areas sclerotised, in about mid-length truncate, with subtruncate, obtuse end, while the basal areas are curved laterally. The subtruncate apical area continued as narrow and elongate, hyaline bursae. This membranous part of the titillators is laterally accompanied by additional hyaline bursae of which the proximal one is provided with long hairs along margin. Measurements: body: male 19–21, female 19.5–22.5; pronotum: male 4.8–5.2, female 4.8–5.5; tegmen: male 29–33, female 30–34; hind femur: male 14.5–16, female 15–16.5; ovipositor: 10–11.5 mm .