Female macropterous. Head, tibiae and tarsi dark brown, femora yellow, pronotum yellow with fore coxae light brown; pterothorax yellowish with light brown markings (darker when fully mature?); tergites VI–VIII brown, X yellow; antennal segment III clear yellow, IV–IX brown; forewing brown at base and apex, with long median brown area, costal vein pale around distal pale area.
Head relatively long, distal maxillary palp segment subdivided. Antennae 9-segmented, sensorium on segments III–IV slender with internal markings, extending to basal half of segment; V–VI sensorium with elongate base. Mesonotum with one pair of accessory setae medially. Metanotum with equiangular reticles medially, with internal dot-like markings. Forewings unusually slender. Abdominal tergites I–III apparently with no transverse lines medially; tergites IV–VIII transversely reticulate; trichobothria on X no larger than base of major setae on X. Sternites with 4 pairs of marginal setae, II–V apparently without discal setae, VI with one or two pairs placed anterolaterally, VII with 4 pairs of discal setae laterally.
Male similar to female but smaller, femora more extensively shaded brown, antennal segments I–III yellow; antennal sensoria distinctly longer. Abdominal tergite I with two longitudinal ridges. Sternites with numerous microtrichia, 4 pairs of marginal setae, II–VI with no discal setae, VII–VIII each with 2 pairs laterally; sternite IX with 2 discal setae.
The genus Desmothrips is known only from Australia, with 18 described species (Pereyra & Mound, 2010). D. postlei is closely related to D. darwini, despite having the mid and hind femora clear yellow in contrast to the dark tibiae.
Known only from Australia
Known only from two specimens taken at Kununurra in Western Australia.
Presumably living on at the base of grasses.
No information available.