OzThrips

Thysanoptera in Australia

Biology

The species in this family apparently all breed in flowers, and they probably have a high degree of host specificity. All four species of Holarthrothrips (=Adiheterothrips ) breed in the male flowers of date palms and it relatives.

Recognition

Stenurothripidae (=Adiheterothripidae) all have nine antennal segments, of which the distal segments are fully distinct from each other, segments II – IX bear transverse rows of prominent microtrichia, and the sensoria on segments III and IV have a characteristic, broadly conical, shape.

Other characters of the body vary considerably between the three genera. Heratythrips differs from the other two in that the tentorium is not apparent within the head, and there are no long setae on the head or pronotum. However, Heratythrips resembles Oligothrips in having the metanotum reticulate, antennal segment IX about twice as long as wide, and abdominal tergite VIII without a posteromarginal fringe of microtrichia. In contrast, the species of Holarthrothrips have the metanotum with concentric rings of sculpture bearing microtrichia, antennal segment IX is about five times longer than wide, and tergite VIII bears a prominent posteromarginal comb.

Genus and species diversity

Only three genera are recognised in the family Stenurothripidae (= Adiheterothripidae). Adiheterothrips is recognised as a junior synonym of Holarthrothrips (Mound et al., 1980), and this genus includes four species (Bhatti, 1986). Oligothrips and Heratythrips both include a single species (Mound & Marullo, 1999; Hoddle et al., 2008). Nomenclatural details of these taxa are available on Mound’s Thysanoptera pages.

Geographic distribution

The members of Holarthrothrips are found between India and the Mediterranean area including the Canary Islands. In contrast, Oligothrips andHeratythrips are both known only from western North America.

Systematics and classification

The Stenurothripidae (= Adiheterothripidae) is one of eight families recognised in the Thysanoptera suborder Terebrantia.

There is no clear morphological evidence that the three genera placed in the Stenurothripidae form a single clade. Moreover, the only available analysis of the morphological data indicated that the genus Holarthrothrips might be sister-genus to the Heterothripidae (Mound & Marullo, 1999). Molecular data derived from the gene 18S rDNA also suggested a close relationship between these taxa (Mound & Morris, 2007).

The family Stenurothripidae was discussed by Bhatti (2006). The nominate genus Stenurothrips Bagnall is based on a fossil specimen on which many structural details cannot be studied (Mound & Morris 2007).

Oz thrips taxa