Haplothrips bituberculatus (Girault)

Mound, Laurence A. & Minaei, Kambiz, 2007, Australian thrips of the Haplothrips lineage (Insecta: Thysanoptera), Journal of Natural History 41 (45 - 48), pp. 2919-2978 : 2948-2950

Haplothrips bituberculatus (Girault)

Podothrips bituberculatus Girault 1927, p 2 .

This species is widespread but never abundant across the whole continent of Australia. Judging from collecting records it is probably predatory on other small arthropods, because only a few specimens are ever taken at one time, and these are found on dead twigs, in galls, and on leaves. In structure it is variable both within and between sites. The number of sensoria on the fourth antennal segment is either three or four, even on the same individual, although most specimens studied from southern Australia have four, and most specimens studied from northern Australia have three. In males, the pronotal anteromarginal setae are often shorter, and the fourth antennal segment longer, than in females. The fore wings are distinctly shaded medially, although specimens from Kununurra in the north of Western Australia have the wings paler.

Recognition

Body and femora dark brown, tarsi yellow, hind tibiae yellow at base and apex but variably brown medially; antennal segment III brownish yellow, remaining segments brown; pronotal major setae light brown; fore wings shaded medially. Head slightly longer than wide; maxillary stylets almost V-shaped, maxillary bridge about one-third of head width; antennal segment III with two sensoria, IV with three or four. Pronotum with five pairs of capitate setae, am setae slender; mesopresternum transverse. Fore tarsal tooth in female small but variably large in male. Metanotum very weakly reticulate medially, median setal pair arising on anterior half; fore wing sub-basal setae capitate; five to seven duplicated cilia present. Tergite IX setae S1 and S2 pointed but not acute.

Large males with two small, seta-bearing tubercles on inner margin of fore tibiae, and fore femora and fore tarsal tooth enlarged; small males with slender fore legs and no tibial tubercles; pronotal anteromarginal setae sometimes small, even no larger than discal setae.

Measurements of one female (in M m) (Western Australia, Yanchep, September 1967). Body length 1640. Head, length 170; median width 168; postocular setae 40. Pronotum, length 130; width 270; major setae am 22, aa 28, ml 36, epim 50, pa 36. Fore wing length 625; sub-basal setae 36, 40, 74. Tergite IX setae S1 80, S2 110, S3 105. Tube length 125; basal width 60; anal setae 160. Antennal segments III–VIII length 44, 46, 46, 42, 40, 28.

Haplothrips collyerae (Mound and Walker) comb. n.

Apterygothrips collyerae Mound and Walker 1986, p 40 .

This species was described as widespread in the North and South Islands of New Zealand, where it was recognised as a predator on the eggs of the mite species, Panonychus ulmi . The original description also referred to two specimens collected near Hobart, Tasmania, and recent observations by John Ireson (Tasmanian Institute of Agricultural Research) indicate that the larvae of this thrips are predatory on the larvae of a thrips species ( Sericothrips staphylinus ) that is useful in the biological control of gorse ( Ulex europea ). A single specimen has also been studied from north-western Tasmania, near Trowutta.

As discussed above, the genus Apterygothrips is a poorly defined assemblage of species that lack wings, or have the tergal wing-retaining setae reduced or absent, and there is no clear evidence that it is anything other than polyphyletic. Considering the variation in wing form and development, also the number of antennal sensoria, among the Australian species of the genus Haplothrips it seems most appropriate to place collyerae in this genus.

Recognition

Macropterous or micropterous. Body colour brown, mid and hind tibiae yellow at base but shaded brown distally and along external margin; all tarsi yellow; antennal segment III yellow, remaining segments brown (Figure 20); major setae pale, fore wing shaded except in basal quarter. Head longer than wide, maxillary stylets about one-third of head width apart, retracted to postocular setae, maxillary bridge complete (Figure 34); postocular setae blunt. Antennal segments III–IV with sensoria slender two on III and two +1 on IV. Pronotal am setae no larger than discal setae, aa and ml setae also short. Mesonotum and metanotum without sculpture medially. Mesopresternum transverse (Figure 35). Fore tarsal tooth small, acute, arising at inner apex of tarsus. Fore wing without duplicated cilia, sub-basal setae blunt; fore wing of micropterae shorter than width of thorax. Tergite II with wing-retaining setae minute (Figure 36), III–VII each with two pairs; tergites II–VII posteromarginal setae S1 weakly capitate to blunt; tergite IX setae acute.

Measurements of macropterous female (in M m) (Tasmania, Hobart, May 2005). Body length 1635. Head, length 175; median width 135; postocular setae 32. Pronotum, length 120; width 235; major setae am 3, aa 20, ml 5, epim 38, pa 38. Fore wing length 600; sub-basal setae 18, 12, 26. Tergite IX setae S1 75, S2 90, S3 100. Tube length 115; basal width 55; anal setae 120. Antennal segments III–VIII length 34, 40, 40, 38, 38, 28.