Bioacoustics of Arnobia tinae

Description. Habitus as shown in Fig. 1 , typical of genus. Head small, with length circa 0.6 times of pronotum length (n = 3, dried specimens). Fastigium tongue-shaped, furrowed medially, narrower than antennal scapus; with apex roundly truncated. Eye prominent; median ocellus round and large. Frons smooth. Pronotum circa 1.3 times longer than wide (n = 3, dried specimens), smooth, with very short and fine hairs sparsely and randomly distributed; dorsal plate with anterior margin slightly concave in the middle with two small broadly rounded lobes; posterior margin with feeble median emargination; lateral keel present but not distinct; lateral lobe circa 1.3 times longer than tall (n = 3, dried specimens), ventral margin straight and posterior margin very broadly rounded. Prosternum unarmed. Meso- and meta-sterna rectangular with rounded edges; metasternum more elongated and less rounded than mesosternum. Tegmen and hind wing fully developed. Tegmen with anterior and posterior margins straight, apex rounded. Tegminal venation: Radius sector (Rs) originates around middle, forked before middle of Rs; veins and veinlets form small polygonal cells. Hind wing with apex distinctively projecting beyond tegmen; exposed apex with ventral margin slightly curved and dorsal margin straight. Legs generally with dense short setae. Anterior coxa with distinct spine. Anterior tibia with internal tympanum conchate and slightly swollen, with slit rather wide; external tympanum open and elongated oval. Male. Stridulatory vein of left tegmen thickened, straight in the middle and slightly curved at the ends, circa 1.9 mm (n = 3, dried specimens) in length; file with 92 (n = 1) teeth closely and evenly spaced. Venations on dorsum of tegmen variable among specimens ( Figs. 2 A–C). Abdominal apex as shown in Figs. 2 D, 2E. Tenth abdominal tergite simple, transverse with posterior margin feebly emarginated in the middle. Epiproct with basal half transverse, lateral margins parallel; apical half tapers strongly into a median lobe with apex obtuse or subacute, slightly setose ( Fig. 2 D). Cercus elongated, gently tapering from basal half to apex; apical half bent at nearly 90 ° from basal half (with long apical narrowing); apex obtuse, with a minute and blunt process ( Fig. 2 D). Subgenital plate elongated; basal part (about two-third of plate) wider and swollen, with basal margin deeply and roundly excised, lateral margins tapering into apical third; apical third with lateral margins parallel, apical margin straight without lateral (nearly indistinct) and median lobes ( Fig. 2 E). Genitalia membranous. Female. Abdominal apex as shown in Figs. 3 A, 3B. Epiproct triangular, slightly wider than long, apex obtuse. Cercus simple, swollen; tapers into a narrow apical third with subacute apex; setose ( Fig. 3 A). Subgenital plate triangular, slightly wider than long; basal margin slightly concave; apical third lobous, with apex rounded ( Fig. 3 B). Ovipositor longer than most species; dorsal valve longer than ventral valve; dorsal and ventral margins smooth; dorsal margin feebly curved basally, straight thereafter; ventral margin very feebly curved; apex subacute ( Fig. 3 A). Gonangulum of ovipositor piriform, ventrally swollen, dorsally acute ( Fig. 3 A). Colouration. In general whitish green when alive. Head whitish green, including the fastigium, frons, clypeus, gena and scapus. Pronotum with dorsal plate green with posterior margin brown; lateral lobe whitish green, unevenly distributed with a few small purple spots. Tegmen appears green, but is hyalinous with veins and veinlets green; posterior margin yellow. In some specimens, few distinct spots along tegmen between R and posterior margins present; some large while others small, but usually white or very pale yellow bordered with tint of black ( Fig. 1 B). In males, dorsum of tegmen basally with a brown spot, weakly defined; distally with smaller and very weakly defined black or dark brown spot. ( Figs. 2 A–C). In female, dorsum of tegmen basally with a large and rounded dark brown spot, well-defined; distally with a smaller and less defined dark brown spot ( Fig. 3 C). Hind wings hyalinous, with veins and veinlets green; exposed apex similar to tegmen, appears more green than covered parts (veinlets more dense than covered parts), but is hyalinous with veins and veinlets green. Abdominal tergite whitish green, with some brown spots; sternite mostly white. Anterior legs generally green. Anterior femur with dorso-basal part with three to four purple bands alternating with yellow/ brown bands; area around tympanum yellow and brown with tint of purple; tarsus white or very pale yellow. Middle and posterior femora basally white with a few sparse but larger purple spots, apical third green with more numerous but smaller purple spots. Middle and posterior tibiae whitish green with few small purple spots; tarsi white or very pale yellow. Measurements. See Table 1 .