Both sexes fully winged. Body size and color variable depending on temperature during development, from small and whitish yellow to large and brown; ocellar pigment usually grey, never red; fore wings pale. Head wider than long; with 2 pairs of ocellar setae; pair III small, arising on anterior margins or just within ocellar triangle; postocular setae pairs I–III about equal to ocellar setae III. Antennae 7-segmented; segments III–IV with short forked sensorium; VII short. Pronotum with 2 pairs of prominent posteroangular setae; posterior margin with 3 (sometimes 4) pairs of setae. Metanotum variable, usually irregularly reticulate medially with lines converging to midpoint at posterior margin; median setae short, arising behind anterior margin; campaniform sensilla absent. Fore wing first vein usually with 4 (varying 2–6) setae on distal half; second vein with about 15 setae. Abdominal tergite II with 3 lateral marginal setae; V–VIII with paired ctenidia, on VIII posteromesad to spiracles; tergite VIII posteromarginal comb complete, microtrichia long and slender; pleurotergites without discal setae, with closely spaced rows of fine ciliate microtrichia. Sternite II with 2 pairs of marginal setae, III–VII with 3 pairs; sternites without discal setae.
Males usually rare; body small and yellow; tergite VIII with marginal comb represented by few irregular microtrichia; sternites III–V with narrow transverse pore plate.
Adult females vary greatly in size and color, from small and yellow to large and dark brown, but consistently lack any red pigment beneath the three ocelli on the head.
The genus Thrips is the second largest genus in the Thysanoptera, and currently includes, worldwide, about 285 species. T. tabaci is unusual within the genus in lacking red pigment around the ocelli, and is usually easily recognized by the closely spaced rows of ciliate microtrichia on the pleurotergites. 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 tabaci Lindeman
Breeding on leaves and in flowers, also predatory as larvae and adults. Males are usually rare (Nault et al., 2006), but have been studied in good numbers from eastern Mediterranean countries and also from New Zealand.
Although particularly abundant on onions, this species is highly polyphagous, breeding on many hosts including monocotyledonous and dicotyledonous plants.
Particularly important on onions and garlic, but also on Brassica and tobacco crops in parts of Europe, and on various other crops including potatoes and greenhouse plants in different parts of the world.
Presumably eastern Mediterranean
Cosmopolitan except for wet tropics.