Female macropterous; body colour brown, legs yellowish, antennal segment III yellow; fore wing brown with base paler. Antennae 7-segmented (rarely with 8 segments), III & IV slightly constricted at apex with short forked sensorium; segment VII short. Head wider than long, with 2 pairs of ocellar setae; pair III stout and arising just outside anterior margins of ocellar triangle; postocular setae pairs I & III shorter than ocellar setae pair III, pair II very small. Pronotum with 2 pairs of long posteroangular setae, posterior margin with 3 pairs of setae. Mesonotum with no lines of sculpture around anterior campaniform sensilla. Metanotum with lines of sculpture longitudinal medially, but transverse at anterior; median setae arising at anterior margin, campaniform sensilla present. Fore wing first vein with 3 setae on distal half, second vein with about 14 closely set setae; clavus with 5 marginal setae, the subapical seta longer than the apical seta. Tergite II with 4 lateral marginal setae; tergites V–VIII with ctenidia present laterally, on VIII posteromesad to spiracles; posterior margin of VIII with comb complete medially but microtrichia small and irregular and sometimes arising in groups; pleurotergites without discal setae. Sternite II with 2 pairs of marginal setae, III–VII with 3 pairs, median pair on VII arising in front of margin; sternite II with 1 to 4 discal setae, III–VII with discal setae varying in number from 6 to 14 in a regular transverse row.
Male similar to female in structure, but smaller and paler; tergite VIII with no marginal comb; tergite IX with median S1 setae longer than S2 and arising closer to S2 than to each other; sternites III–VII with transverse pore plate anterior to row of about 8 discal setae.
Although very similar, this species can usually be distinguished from T. hawaiiensis using the character states given by Bhatti (1999). Generally, T. florum adults have the subapical veinal seta on the fore wing clavus longer than the apical seta, and the mesonotum has no lines of sculpture around the anterior pair of campaniform sensilla. However, individuals are sometimes found that are not easily assigned to either species. The genus Thrips is the second largest genus in the Thysanoptera, and currently includes, worldwide, about 285 species. 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 florum Schmutz
Oriental flower thrips
Breeding in flowers.
Apparently highly polyphagous, adults having been taken in the flowers of many plants.
Not recorded as a serious pest.
Widespread across Asia from India to the Pacific, Fiji, Tahiti, eastern Australia, also Florida, the West Indies, Costa Rica and Guatemala. This species is likely to be introduced to California through the horticultural trade.