Distinguishing features

Both sexes fully winged. Body brown, legs brown with tarsi yellow; antennal segment III light brown, remaining segments dark brown; fore wings brown with base sharply paler. Antennae 7- or 8-segmented; segments III & IV distinctly constricted at apex, each with forked sense cone; VII short. Head wider than long; 2 pairs of ocellar setae, pair III as long as lateral margin of ocellar triangle, arising just outside triangle; postocular setae pairs I, III and V about as long as ocellar setae III. Pronotum with 2 pairs of long posteroangular setae; posterior margin with 3 pairs of setae. Metanotum with closely spaced, anastomosing, longitudinal striae on posterior half; median setae arise behind anterior margin; campaniform sensilla present. Fore wing first and second veins with complete rows of setae. Abdominal tergite II with 3 lateral marginal setae; tergites V–VIII with ctenidia present laterally, on VIII posteromesad to spiracles; tergite VIII posteromarginal comb complete, microtrichia widely-spaced, slender, sometimes irregular; pleurotergites with 2 or 3 discal setae. Sternites II–VII with 3 pairs of marginal setae; II without discal setae, III–VII with 6–14 discal setae.
Male smaller than female, light brown; tergite VIII marginal comb weakly developed; tergite IX setae S1 much longer and stouter than S2 and arising anterior to these setae; sternites III–VII each with transversely oval pore plate, discal setae arising laterally.

Related species

This polyphagous New Zealand species is not known from California, but is included here because it has the potential to be introduced. T. obscuratus is unusual within the genus Thrips for having three instead of two marginal setae on the second abdominal sternite, a character state that is shared with four species from New Zealand and three from New Caledonia (Mound & Masumoto, 2005). Thrips genus is the second largest genus in the Thysanoptera, and currently includes, worldwide, about 295 species. All members of Thrips genus 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; Mound & Masumoto, 2005).

Biological data

Highly polyphagous, and breeding in flowers. Larvae have been recorded from 51 plant species in New Zealand, including 36 plant species that are not native to to that country (Teulon & Penman, 1990). This thrips sometimes causes damage to crops of stone fruits in New Zealand.

Distribution data

Known only from New Zealand, but a potential immigrant to California.

Family name

THRIPIDAE - THRIPINAE

Species name

Thrips obscuratus (Crawford JC)

Original name and synonyms

Isoneurothrips obscuratus Crawford JC, 1941: 63

References

Mound LA & Masumoto M (2005) The genus Thrips (Thysanoptera, Thripidae) in Australia, New Caledonia and New Zealand. Zootaxa 1020: 1–64.

Palmer JM (1992) Thrips (Thysanoptera) from Pakistan to the Pacific: a review. Bulletin of the British Museum (Natural History) Entomology Series 61 (1): 1–76.

Teulon DAJ & Penman DR (1990) Host records for the New Zealand flower thrips (Thrips obscuratus (Crawford) Thysanoptera: Thripidae). New Zealand Entomologist 13: 46–51.

Thysanoptera Californica