Bioacoustics of Mesagraecia

Diagnosis. Fastigium verticis conical, not reaching tip of scapus when directed anteriorly. Pronotal disc flattened and rounded into paranota; disc prolonged, covering stridulatory area in male; ventral margin concave, little descending posteriorly. Tegmen not fully reaching or surpassing hind knees, its apex roundly truncate. Prosternum unarmed. Mesosternal lobes conical or terminating into cones. Male tenth abdominal tergite prolonged behind and roundly excised in middle. Male cerci with apical modification and a subapical internal process; with or without a second, proximal internal process. Phallus with two large membranous lobes that are supported on internal side by long titillators. Female subgenital plate fully membranous or only lateral areas sclerotised. Ovipositor laterally compressed, widest (highest) in or little behind mid length. Hind wings of all species known dark (blackish) with transparent anterior margin. The genus is rather unique within the Indo-Malayan Agraeciini . It is probably remotely related to Jambiliara with which it shares the unarmed prosternum, a modification of the tip of cercus, and the long titillators although of different shape. The general outline of the pronotum with deep lateral lobes and apical prolongation in male, and the laterally compressed ovipositor are also similar between both genera. Mesagraecia differs in the pronotum being smooth instead of strongly granular and with secondary wrinkles, the male subgenital plate having the styli inserted at tip instead of ventral surface of apical lobes, and by the specific shapes of male cerci and titillators. A pair of projections at the end of the prolonged male tenth abdominal tergite are present in Jambiliara and the new Malayan species of Mesagraecia but absent in the two species from Thailand and Vietnam . The shape of the tegmen with truncate tip resembles the situation in Paragraecia . Mesagraecia differs by the shape, especially the deep lateral lobes of pronotum, the absence of prosternal spines, and different ground plans of the male cerci, titillators and female subgenital plate. The shape of the pronotum with the deep lateral lobes shows some superficial similarity with that of Axylus and related genera. Mesagraecia differs in the absense of prosternal spines, the mesosternal lobes not spiniform, the hind knee lobes being uni- instead of bi-spinose, and different ground plans of the male cerci, titillators and female subgenital plate. Species richness and distribution. So far, three species from various parts of Southeast Asia are known: Mesagraecia bicolor Ingrisch, 1998 and Mesagraecia gorochovi Ingrisch, 1998 from Thailand and Vietnam ; and Mesagraecia laticauda (Karny, 1926) from south-eastern Perak, Peninsular Malaysia ( Ingrisch, 1998 ; Kim & Pham, 2014 ). Below, Mesagraecia larutensis sp. n. is described from central Perak.