Bioacoustics of Gibbosella

Description : Apterous female: Colouration: Basic colouration dark brown with pale markings on legs and connexiva. Structure: Body small, slightly elongated. Entire body shining. Setae on body variously sized, pale. ( Figs 1 , 2 ). Head: Head slightly elongated, cylindrical, and as long or slightly longer than pronotum. Eyes small, located on dorsolateral part of the head, ocelli absent. Eyes almost reaching dorsal line of the head in lateral view. Antennifers distinctly visible, short, robust, and slightly arcuate in dorsal view. Full number of antennomeres is unknown—both specimens have incomplete antenna with only 4 antennomeres. Second antennal segment the longest. Mandibular plates, distinctly enlarged and convex (distinctly visible in lateral view). Second rostral segment 1.5 times wider than first segment in lateral view. Pronotum: Anterior pronotal lobe distinctly enlarged vertically and longer than posterior lobe. Apical margin of anterior pronotal lobe indented - indentation rounded. Lateral pronotal margins rounded. Lateral parts of apical margin of anterior pronotal lobe with distinct, rounded calli. Posterior pronotal lobe with sculpturation in lateral parts, less wide than anterior lobe. Anterior and posterior pronotal lobes with longitudinal sutures in the middle, on anterior lobe sutures distinctly depressed in basal part. Scutellum: Apices rounded, distinctly curved, and directed dorsally. Distinct longitudinal depression, divided in basal part, visible in all length of scutellum. Thorax: Lateral margins of prosternum and mesosternum distinctly unattached in the height of coxae. Stridulatory organ strongly elongated in ventral view with rounded apex and reaching over fore coxae. Prothorax with distinct, rounded process in lateral view at height of coxae. Mesosternum with distinct, longitudinal groove distinctly wider in basal part. Mesosternum slightly curved and its basal part directed ventrally (lowest part of the thorax). Metasternum triangular in shape with distinct longitudinal groove (wider in apical part). Legs: Legs thin, slender. All femora gradually thickened from basal to apical part with distinctly thinner apex. Tarsomere 1 shortest, tarsomere 3 longest – distinctly longer than tarsomere 1 and 2 together. Abdomen: Abdomen ovoid, slightly elongated. Margins of each terga and sterna with lace sculpturation. Connexiva large, dorsally elevated. Ventral part of abdomen slightly convex. Each sterna distinctly convex medially. Differential diagnosis : The genus Gibbosella n. gen. can be easily recognized from other genera of Ectrichodiinae distributed on Madagascar by its very small, robust, and shining body. Head cylindrical, slightly elongated with relatively small and upper-placed eyes. Head without ocelli. Second antennal segment the longest. Pronotum vertically enlarged, distinctly divided on anterior and posterior pronotal lobe by very wide transversal sutures. Posterior pronotal lobe small. All femora distinctly thinner on apex. Abdomen wide and rounded, slightly longitudinally elongated. This genus can be easily recognized by its distinctive, extremely gibbose pronotum ( Figs 3, 4 ).