Male apterous; body bicoloured, with head dark brown and yellow at base, and thorax, legs and pelta yellow to light brown; abdominal segments II–X mostly dark brown, but segment V usually with two light spots laterally; antennomeres I–II and IV light brown, III yellow, V–VIII dark brown. Antennae 8-segmented, antennomere IV with 2 sense cones; V and VI with a small apical tubercle. Head longer than wide, slightly constricted at base, dorsal surface reticulated in front of eyes and basally; eyes elongated ventrally, ocelli absent; maxillary stylets more than half of head width apart, extending to middle of head. Pronotum with 4 pairs of well-developed but short setae, prosternal basantra present. Meso- and metathorax laterally constricted. Metanotum longitudinally reticulated, almost striate medially, with a pair of short median setae. Metathoracic sternopleural sutures present and elongate. Pelta almost trapezoidal, with irregular reticulation posteriorly. Abdominal sternites without a pore plate. Tube with straight margins, about 1.5x as long as basal width, without lateral setae. Fore legs slightly enlarged, fore tarsi with a tooth.
Female not studied.
Intraspecific variation
The color and size of antennal segment IV seems to be variable between specimens (Mound & Marullo 1996).
Genus and similar species information
Compsothrips is a genus composed of 26 species, widely distributed in the tropics. The members of this genus are ant mimics, with a medially constricted body and lacking wings. Besides that, their head is usually elongated, the antennae are 8-segmented, basantra and metathoracic sternopleural sutures are present, and the abdomen is robust with a short tube. Antennomere IV has only two sense cones, contrasting the 4 sense cones more commonly seen in Idolothripinae. Compsothrips graminis is distinguished from C. bicolor and C. hoodi for having pale spots laterally on abdominal segment V; and from C. brasiliensis for having a bicolored body.
Distribution around the world
Described from Trinidad and Tobago and recorded from Argentina, Brazil, Panama and Paraguay.
