Female macroptera. Body pale yellow, antecostal ridges on tergites III–VIII weakly shaded across full width of segments, sternites III–VII with weak shading; fore wings uniformly weakly shaded; antennal segment I pale, II pale to weakly shaded, III mainly pale, V–VIII uniformly dark. Head with vertex closely striate, ocellar triangle with reticulate pattern; bases of ocellar setae pair III closer together than length of these setae, arising between midpoints of posterior ocelli; two pairs of post-ocellar setae each at least 0.75 as long as ocellar setae pair III. Pronotum with transverse striae irregular and widely separated; posteromarginal setae S2 sometimes longer than S1, S3 never longer than S1 and S2. Metanotum equiangular reticulate; median setae well behind margin. Fore wing clavus usually with 4 marginal setae; first vein setae 3–4+1–4+1+1+0–1+0–1+0–1; second vein 4 setae; posteromarginal fringe cilia wavy. Tergite I median setae usually extend beyond posterior margin of tergite, III–V with bases of median setae separated at least 2.25 times the length of these setae; tergal microtrichial fields with 3 discal setae; VIII with posteromarginal comb of microtrichia complete, no discal microtrichia medially; tergite IX without discal microtrichia. Sternites with lateral microtrichial fields extending mesad of marginal setae S2.
Male macroptera. Similar in colour and sculpture to female, but smaller; sternites commonly with one transverse row of microtrichia close to antecostal ridge; abdominal segment IX with a pair of dark drepanae ventrolaterally with pointed apices curving dorsally; aedeagus without either lateral arrays of spines or terminal spines.
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. The pronotal transverse striae of S. frondis are more widely separated than in any other Australian member of the genus.
Known only from Australia.
Australian Capital Territory, New South Wales.
Feeding and breeding on young fronds.
Dicksonia spp (Dicksoniaceae), Cyathea spp (Cyatheaceae).
Scirtothrips frondis Hoddle & Mound
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