Stethorini Dobzhansky, 1924

Tribe Stethorini Dobzhansky, 1924 View in CoL

Diagnosis. Form very small ( 0.80–1.30 mm long), elongate to slightly broader oval, dorsum densely pubescent. Both sides black, except antennae, mouthparts, and legs piceous to yellowish brown. Antenna 11-segmented, rarely 10-segmented. Prosternal process without carinae, medially convex and produced forward in the form of a broad arch, partly covering mouthparts. Abdomen with six ventrites, abdominal postcoxal lines complete ( Stethorus ) or incomplete and apically recurved ( Parastethorus ).

Biology. All Stethorini are specialist predators of spider mites ( Tetranychidae ) and false spider mites or flat mites ( Tenuipalpidae ), and cosmopolitan in distribution ( Chazeau 1985; Biddinger et al. 2009). Only two genera, Stethorus and Parastethorus are recognized under Stethorini with about 100 species. Kapur (1948) revised 21 old world species of Stethorus including five commonly occurring Indian species. After this, only three species, S. indira Kapur (1950) , S. keralicus Kapur (1961) and S. forficatus Poorani (2017) have been added in the last seven decades, with scores of undescribed species.