Female macroptera. Body yellow with brown marking medially on tergites III–VII, sternites without brown markings but antecostal ridges on tergites and sternites dark brown; fore wings usually strongly shaded but paler toward apex; antennal segment I pale, II shaded, III–VIII dark. Head about twice as wide as long, postocular and ocellar region closely striate; ocellar setae pair III arise between posterior ocelli, well behind tangent between their anterior margins; compound eyes with no ommatidia strongly pigmented; two pairs of post-ocellar setae as long as ocellar setae pair III. Pronotum closely striate, posteromarginal setae S2 30–35 microns, clearly longer than S1. Metanotal sculpture variable, usually transversely arcuate anteriorly, with irregular longitudinal reticulations or striations posteriorly; median pair of setae far behind anterior margin. Fore wing scale with 4 marginal setae; second vein with 2 setae; posteromarginal fringe cilia all straight. Tergites III–V with bases of median setae usually closer together than length of these setae; tergal microtrichial fields with 3 discal setae; VIII with discal microtrichia present anteromedially, posteromarginal comb complete; tergite IX with discal microtrichia present posteromedially. Sternites with microtrichia extending across median area on posterior half.
Male macroptera. Similar to female in colour and sculpture, but smaller; aedeagus apparently with no armature.
The genus Scirtothrips comprises over 100 described species worldwide, with 21 species known from Australia most of which are endemics to this continent. These species all have the lateral thirds of the abdominal tergites covered in closely spaced rows of fine microtrichia, and in many species the sternites also bear similar microtrichia. The antennae are 8-segmented, except in S. casuarinae and S. solus, both forewing veins have an irregular and incomplete setal row, and a median spinula is present on both the meso and metafurca. S. dorsalis is similar to S. aurantii in having microtrichia extending fully across the sternites, unlike any other species of Scirtothrips in Australia. However, the males are readily distinguished by the hind femora lacking a setal comb in S. dorsalis, and whereas the forewing cilia are straight in this species they are wavy in S. aurantii. Molecular differences have been demonstrated between populations, suggesting that a group of sibling species is involved (Hoddle et al., 2008).
Widespread from Pakistan to Japan and Australia; introduced in Israel and Carribean area.
Widespread across northern Australia.
Feeding and breeding on young leaves and immature fruits.
Highly polyphagous, and locally a serious pest, but populations may show localised specificity.
Scirtothrips dorsalis Hood
Hoddle MS & Mound LA. 2003. The genus Scirtothrips in Australia (Insecta, Thysanoptera, Thripidae). Zootaxa 268: 1-40. http://www.mapress.com/zootaxa/2003f/zt00268.pdf
Hoddle MS, Heraty JM, Rugman-Jones PF, Mound LA & Stouthamer R. 2008. Relationships among species of Scirtothrips (Thysanoptera: Thripidae, Thripinae) using molecular and morphological data. Annals of the Entomological Society of America 101: 491-500.