Female macropterous. Body and legs brown, fore tibiae and tarsi paler; antennal segment III yellow, IV yellowish with distal third darker, V–IX increasingly dark; forewing and clavus uniformly fuscous, veins dark.
Head with postocular region shorter than eye length, median pairs of postocular setae stout; distal maxillary palp segment subdivided. Antennae 9-segmented, sensorium on III straight and not extending to mid-point, on IV short but curved around apex, without internal markings. Mesonotum with 2 to 4 pairs of accessory setae medially. Metanotal reticles equiangular, without internal markings. Abdominal tergite I apparently without sculpture medially; trichobothria on X at least twice as wide as base of major setae on X. Sternites with 4 pairs of marginal setae and 2 to 5 pairs of discal setae laterally but none medially.
Male similar to female but smaller. Abdominal tergite I with two longitudinal ridges. Sternites with 4 pairs of marginal setae, VIII–IX with about 8–10 discal setae.
The genus Desmothrips is known only from Australia, with 18 described species (Pereyra & Mound, 2010). D. stepheni is probably part of the D. crespii complex, although it has one or more pairs of setae on the head and pronotum unusually stout.
Known only from Australia
Known only from one site in the arid zone of north western Queensland