Revision Of Trichromothrips and related genera (Terebrantia: Thripidae)

Abstract

The genus Trichromothrips Priesner, 1930 is distributed worldwide, although species diversification has taken place predominantly in South Asia. Its taxonomy is discussed, and the genus is redescribed. 27 species, segregated into 10 sections, are included. It is closely related to Laplothrips Bhatti, 1972 and also has affinities with Neocorynothrips Ram. & Marg., 1939. A key to the species of these three genera is provided. Cricothrips Trybom, 1912 at first sight looks strikingly similar to species of Trichromothrips in the structure and chaetotaxy of body. But closer scrutiny reveals that it is separable by the presence of mesothoracic sternopleural sutures, longitudinally split tergum X of female, 2 pairs of campaniform sensilla on abdominal tergum DC, and with male having antennal segments IV to VI enlarged and with more numerous long setae, and lacking gland areas on abdominal sterna. The genus Diarthrothrips Williams, 1915 is also compared. The character of facetal pigmentation on the venter of eye, previously known in only 5 species of the genus, is now reported for the first time in 10 species of Trichromothrips and in 5 species belonging to the genera Laplothrips, Neocorynothrips, Cricothrips, and Diarthrothrips. Facetal pigmentation has now been found in 2 species of Trichromothrips, but is absent in 13 species; the condition in 12 species needs to be ascertained. The male genitalia in Trichromothrips are described for the first time, including the hypophallus and sketches of the membranous phallus in three species. The biology of the aquatic species Trichromothrips billeni (zur Strassen, 1995), living together with Pteridothrips pteridicola (Karny, 1914), is discussed. The two species breed underwater in leaf tubes produced by them on the water fern Microsorum pteropus in Java (Indonesia).