Bolacothrips striatopennatus (Schmutz)

Mound, Laurence A., 2011, Grass-dependent Thysanoptera of the family Thripidae from Australia, Zootaxa 3064 (1), pp. 1-40 : 15

Bolacothrips striatopennatus (Schmutz)

( Figs 26–30 )

Thrips striatopennata Schmutz, 1913: 1002

This species was described from Sri Lanka, and is known from India and Indonesia to Japan, Taiwan and Guam; the specimens available from Australia are listed below. The chaetotaxy of abdominal tergites I–II is considered important in distinguishing species in this genus ( Bhatti, 1983; Masumoto & Okajima, 2002). In striatopennatus the median setae on tergite I are stated to be more than 26 microns in length, and on tergite II the lateral margin setal row is considered to comprise three setae, with a fourth seta placed mesad of this row ( Fig. 29 ). Moreover, antennal segment II of striatopennatus lacks microtrichia, abdominal tergites II–IV are commonly slightly shaded anterolaterally, and both sexes can be micropterous. In contrast, B. yasuakii from Japan, has at least one clear row of microtrichia on antennal segment II, the median setae on tergite I are 9–14 microns long, the four lateral setae on tergite II are arranged in a straight row, the abdomen has no dark shadings, and both sexes are macropterous.

The available specimens from Australia appear to be intermediate between these two species. Antennal segment II of some specimens bears a few very weak microtrichia, but these are considerably weaker than those on the type specimens of yasuakii . The median setae on tergite I vary in length 15–20 microns ( Figs 26–27 ), although one micropterous female has them 25 microns long ( Fig. 28 ). Moreover, the length of these setae is sometimes bilaterally asymmetrical. The setal row laterally on tergite II in the Australian specimens usually has one seta placed slightly mesad of the row ( Figs 26–28 ), but again this is not always bilaterally symmetrical. None of the specimens has any shading laterally on the tergites. The initial assumption was that the Australian populations represent a new species, but consideration of the variation amongst the available specimens led to the conclusion that, at present, they are better regarded as extreme variants of a widespread Asian species.

Material studied. Queensland; Brisbane, Mt Coot-tha, 8 females, 2 males (all macropterae), 20.v.2004; same locality, 1 female microptera, 20.x.1985; same locality, 1 female, 1 male from Themeda australis , 22.iii.1968; Brisbane Forest Park, 1 female macroptera, 21.viii.2004, 1 female microptera, 16.i.2006; Cairns, 1 male microptera, 7.xi.2008. New South Wales, 30km west of Batemans Bay, 2 females, 3 males (all micropterae), 13.i.1999, 1 female macroptera, 9.xi.2002; Ettalong, 2 females from grasses, 28.vi.1968; Windsor, 1 female from grass, 19.vi.1968. Victoria, Mt Napier, 1 female microptera, 25.iii.2005.

Figures

FIGURES 23 – 30. Grass living Thripinae. Arorathrips mexicanus 23 – 24: (23) head & thorax; (24) meso & metasterna. (25) Chirothrips manicatus, meso & metasterna. Bolacothrips striatopennatus 26 – 30: (26 – 28) tergites I – II, females from Mt Coottha, Brisbane; (29) tergites I – II, female from Thailand; (30) tergites VII – VIII, female from Thailand.