Both sexes fully winged. Body brown with purple internal pigment; legs brown, mid and hind tarsi light brown, fore tarsi and apical third of fore tibiae bright yellow; antennal segments III – IV clear yellow, V – VI yellow with apices variable shaded; major setae brown; fore wings pale, scarcely shaded at base. Head distinctly longer than wide; maxillary stylets retracted to eyes, close together medially; eyes not prolonged ventrally; postocular setae pointed, shorter than eye length. Antennae 8-segmented; segment III with no sensoria, IV with four sensoria, VIII short and broad at base. Pronotum with 4 pairs of weakly capitate major setae, midlateral setae not developed; prosternal basantra and ferna well developed, mesopresternum reduced to paired lateral triangles. Fore tarsus with small pointed tooth. Metanotum closely striate medially. Fore wing constricted medially, without duplicated cilia. Tergite IX setae S1 finely acute, longer than tube.
Male similar to female, but fore tarsal tooth larger; tergite IX setae S2 short and stout; sternite VIII with no pore plate; pseudovirga of aedeagus slender.
The genus Leptothrips is related to Haplothrips, but the metanotal sculpture is closely striate not reticulate, and larvae and adults usually have extensive purple internal pigment. In total, 38 species are listed under Leptothrips, all from the Americas. Johansen (1987), in describing 22 of these as new species, recorded 11 Leptothrips from California, although only seven were listed by Hoddle et al. (2004). The validity of some of the species in the genus remains questionable, as discussed here under L. mali. The problem is that many of these species were differentiated on character states that are very difficult to observe on their type specimens because these are poor quality slide-mounts. Moreover, there is little recorded habitat segregation between several of the nominal species, given that they are all considered to be predators of other arthropods. L. purpuratus is distinguished from the other members of the genus by the lack of a sensorium on the third antennal segment.
Leptothrips pupuratus (Hood)
Presumably predatory on other arthropods on desert shrubs.
Adults taken from various plants, but particularly Atriplex (Chenopodiaceae).
Arizona, California, Nevada.