Both sexes fully winged. Body and legs yellow, major setae pale; antennal segments V–VI with apex brown, VII brown; fore wings pale. Head wider than long; two pairs of ocellar setae; pair III small, arising outside ocellar triangle; postocular setae pair I as long as ocellar setae III. Antennae 7-segmented; segments III–IV with short forked sensorium. Pronotum with many closely spaced transverse sculpture lines; 2 pairs of prominent, but not elongate, posteroangular setae; posterior margin with 3 pairs of setae. Metanotum with closely spaced straight lines converging to posterior margin, at anterior with irregularly transverse lines; median setae arising behind anterior margin; campaniform sensilla absent. Fore wing first vein with 3 setae on distal half; second vein with row of about 14 setae. Abdominal tergite II with three lateral marginal setae; tergites V–VIII with paired ctenidia laterally, on VIII posteromesad to spiracles; tergite VIII posteromarginal comb absent medially, with a few slender microtrichia laterally; pleurotergites without discal setae, with oblique rows of fine microtrichia. Sternite II with 2 pairs of marginal setae, III–VII with 3 pairs; sternites without discal setae.
Male smaller than female; tergite VIII with no marginal comb; sternites III–V with broad transverse pore plate.
Nakahara (1994) indicates that the body of this species is variable in color, from yellow to yellowish brown to brown; the above notes are based on yellow specimens identified by W. Ewart.
The genus Thrips is the second largest genus in the Thysanoptera, and currently includes, worldwide, about 285 species. T. brevipilosus is similar to pale individuals of T. tabaci in the presence of rows of microtrichia on the pleurotergites, but has red ocellar pigment and the metanotum is closely striate. All members of genus Thrips lack ocellar setae I on the head, and they all have ctenidia on tergite VIII posteromesad to the spiracles. Other characters, such as number of antennal segments, number of setae on the fore wing veins, and number of discal setae on the sternites are variable between species (Palmer, 1992; Nakahara, 1994; Mound & Masumoto, 2005).
Thrips brevipilosus Moulton
Presumably breeding in flowers
Collected from a wide range of plants in various families, with no apparent specificity.
California and several other western States of the USA (Nakahara, 1994).