Female macropterous. Body sharply bicoloured; abdominal segments IV–VI yellow, I–III light brown, VII–X and head dark brown, pronotum and metanotum yellowish; legs mainly light brown; antennal segment III yellow, IV yellow with apex variably shaded, V–IX brown; forewing (and clavus) brown at extreme base, with long median brown area and short dark area at apex, costal vein pale.
Head with postocular region longer than eye length; distal maxillary palp segment subdivided. Antennae 9-segmented, III–IV with weakly sinuous sensorium extending to basal half of segment, with internal markings. Mesonotum with 2 or 3 pairs of accessory setae medially. Median metanotal reticles slightly elongate, with internal dot-like markings. Abdominal tergite I with transverse lines laterally but not medially; trichobothria on X smaller than base of major setae on X. Sternites usually with 4 pairs of marginal setae, VI with 2 pairs of discal setae laterally, VII with 4 pairs laterally but none medially.
Male similar to female but smaller, antennal segments I–II and all legs yellow. Abdominal tergite I with two longitudinal ridges. Sternite VIII with 3 pairs of lateral discal setae, IX with about 10 discal setae arranged irregularly.
The genus Desmothrips is known only from Australia, with 18 described species (Pereyra & Mound, 2010). D. darwini is one of the distinctively bicoloured species in this genus, with abdominal segments IV–VI yellow in contrast to the remaining dark abdominal segments. This species is closely related to D. postlei from Western Australia.
Known only from Australia
Known only from around Darwin
Collected from short grass and sedges.
Despite living at ground level, there is no evidence that this species is predatory or an ant mimic, unlike Gelothrips cinctus with which it has been collected.