Stenchaetothrips Bagnall

Currently, 32 species are listed in this genus, all from the Oriental region apart from one described from Sudan and another from Brazil. These thrips all breed on the young leaves of grasses, and their feeding can cause visible damage. Three species are here recorded from Australia, all from the northern half of the continent. One of these is the oriental Rice Thrips, a second is another Asian species that is here interpreted as also having been introduced to the Neotropics, and the third is a new species described below. Bhatti (1982) provided a key to 15 species from India, and Wang (2000) provided a key to a further five species from Taiwan. However, there is possibly further synonymy to be recognised within the genus; for example, the holotype and one paratype female of S. spinalis from Philippines have been studied, and contrary to the original description the metanotum does not have campaniform sensilla; this species therefore cannot at present be distinguished from S. tenebricus from southern India as defined by Bhatti (1982).

Key to Stenchaetothrips species from Australia

1. Body and legs almost entirely yellow, tergite X variably shaded; fore wings pale; abdominal tergite VIII posterior margin with no microtrichial comb (Fig. 88); postocular setae pair II more than half as long as pairs I and III (Fig. 86)........... indicus

-. Body extensively brown, fore wings deeply shaded; tergite VIII with complete comb of equally long microtrichia (Figs 82, 85); postocular setae pair II much shorter than I or III (Figs 80, 83)............................................. 2

2. Metanotal campaniform sensilla present (Fig. 80); tergite VII posterior margin with small posteriorly directed triangular teeth (Fig. 85); fore wing slightly paler near base; antennal segment V largely yellow; male with pronotum and pterothorax yellow or at least paler than head and abdomen.................................................... bambusicola sp.n.

-. Metanotal campaniform sensilla absent; tergite VII posterior margin with laterally directed teeth present only toward lateral margins (Fig. 82); fore wing uniformly shaded, base not paler; antennal segment V brown (Fig. 81); male either uniformly brown, or head and pronotum paler than abdomen..................................................... biformis