Recognition data

Distinguishing features

Female macroptera. Body brown to dark brown, tarsi and fore tibiae paler; antennal segments III and apex of II yellow, IV light brown, V–VII brown; fore wings light brown, clavus darker. Antennae 7-segmented, III–IV with short forked sensorium. Head about as long as wide or slightly longer, without sculpture between ocelli; 2 pairs of ocellar setae, pair III shorter than pair II, arising just anterior to hind ocelli; postocular setae variable, pair II as long as distance between hind ocelli. Pronotum with 2 pairs of long posteroangular setae; posterior margin with 2–3 pairs of setae. Metanotum longitudinally striate, striae converging posteromedially; campaniform sensilla absent, median setae arise behind anterior margin. Mesofurca without spinula. Fore wing first vein with 2–4 setae on distal half; second vein with complete row of about 12 setae. Tergites II–VIII with no sculpture medially, median setae small, wide apart; V–VIII with paired ctenidia laterally, on VIII posteromesad to spiracle; posteromarginal comb complete with irregular slender microtrichia. Sternites without discal setae, posterior margins with irregular, small dentate microtrichia; sternites IV–VI sometimes with small and poorly developed pore plate medially; setae S1 on sternite VII arising just in front of margin.

Male macroptera. Similar to female but smaller; tergites II–VII posterior margin with small, laterally pointing teeth, VIII with similar teeth arranged irregularly; sternites frequently bearing many discal microtrichia, posterior margins with irregular dentate microtrichia, III–VII with transverse pore plate.

Related and similar species

The genus Stenchaetothrips currently includes 32 species, all associated with Poaceae and all originally from the Old World tropics. S. minutus is particularly similar to the rice thrips, S. biformis, but has the basal half of antennal segment VI yellow, whereas this segment is almost uniformly brown in S. biformis. A suggestion that specimens from Europe can be distinguished from specimens on rice in the Oriental and Neotropical regions (Vierbergen, 2004) requires further confirmation.

Distribution data

General distribution

Widespread from Pakistan to Philippines and Australia; also Europe, Guyana, Colombia, Surinam.

Australian distribution

New South Wales, Queensland.

Biological data

Life history

Feeding and breeding on young leaves, particularly seedling rice plants, but probably also on young plants of other Poaceae.

Host plants

Oryza, Phragmites, Saccharum (Poaceae). The Oriental Rice Thrips is a serious pest of seedling rice in much of Asia, but is not recorded from this crop in Australia. In June 2012 this species was found breeding on eedling sugar cane in Queensland

Taxonomic data

Current valid name

Stenchaetothrips biformis (Bagnall)

Original name and synonyms

• Bagnallia adusta Bagnall, 1913: 238
• Bagnallia biformis Bagnall, 1913: 237
• Bagnallia melanurus Bagnall, 1913: 238
• Thrips (Bagnallia) oryzae Williams, 1916: 353
• Thrips holorphnus Karny, 1925: 15
• Plesiothrips o Girault, 1929: 1
• Thrips dobrogensis Knechtel, 1964: 479
• Chloethrips blandus zur Strassen, 1975: 78

References

Vierbergen G. 2004. Eight species of thrips new for the Netherlands and some taxonomical changes in Stenchaetothrips, Thrips and Hoplothrips. Acta Phytopathologica et Entomologica Hungarica 39: 199-209.

Mound LA. 2011. Grass-dependent Thysanoptera of the family Thripidae from Australia. Zootaxa 3064: 1–40. http://www.mapress.com/zootaxa/2011/f/zt03064p040.pdf