Scirtothrips dorsalis Hood, 1919: 90

Ng, Y. F., Mound, L. A. & Azidah, A. A., 2014, The genus Scirtothrips (Thysanoptera: Thripidae) in Malaysia, with four new species and comments on Biltothrips, a related genus, Zootaxa 3856 (2), pp. 253-266 : 257-258

Scirtothrips dorsalis Hood, 1919: 90

( Figs 5–8 )

Female macroptera. Body pale yellow, femora, tibiae and tarsi pale; antennal segment I pale, segment II variable, segments III–VIII shaded to dark; ocellar area sometimes shaded, also frons between antennal sockets; fore wing base and clavus commonly shaded, wing pale at apex; abdominal tergites IV–VII with weak to strong brown area medially not extending laterally to setal pair S2, antecostal ridge dark and continuous medially; sternites without shaded area, antecostal ridge on IV–VII dark. Antennae 8-segmented, forked sensoria on III–IV short, not reaching more than one-third the length of succeeding segment; ocellar triangle with closely spaced transverse striae, ocellar setae III arising between hind ocelli, 2 pairs of po setae as long as ocellar setae III. Pronotum closely striate, with about 12–15 discal setae; 4 pairs of posteromarginal setae, pm 2 pair not elongate, usually less than 30 microns long and about twice as long as pm 1. Metanotum anterior third with arcuate transverse striae, irregular longitudinal reticulations posteriorly; median setae arise behind anterior margin. Fore wing second vein with 2 setae; clavus with 4 marginal setae, one discal seta. Abdominal tergites II–VI with S1 small, closer together than their length; VIII with microtrichia extending across anterior median area, IX–X with microtrichia present posteromedially; sternites III–VII with rows of microtrichia extending across segment on posterior half.

Male macroptera. Similar to female but smaller; abdominal tergite IX without drepanae.

Comments. Females collected from the leaves of tea in Pahang, Cameron Highlands, are darker than females of the typical form of this species that is common in Malaysia from lowland sites. The darker form has antennal segment II shaded and the tergal shaded area more extensive, also the ocellar area and frons between the antennal sockets dark. The significance of this colour form is not known, but it may be associated with lower temperatures during pupation. Scirtothrips dorsalis is widespread in Asia and northern Australia, and introduced to Israel and Florida. Although certainly polyphagous, there is little precise information on the range of plant species on which it can actually breed.

Figures

FIGURES 5–8. Scirtothrips dorsalis Hood. (5) Head and pronotum; (6) Antenna; (7) Metascutum; (8) Abdominal tergites IV–VIII.