Thrips australis (Bagnall)

Mound, Laurence A., 2010, Species of the Genus Thrips (Thysanoptera, Thripidae) from the Afro-tropical Region, Zootaxa 2423, pp. 1-24 : 6

Thrips australis (Bagnall)

Isoneurothrips australis Bagnall, 1915: 592

This species breeds particularly in the white flowers of Eucalyptus species, but also in similar flowers of a few other Myrtaceae . Although native to Australia, it has been introduced around the world almost wherever Eucalyptus trees are grown. It can produce very large populations, and adults will then disperse and be found in the flowers of many different plants. It is variable in colour and size, and as a result has been described under four other names ( Mound, 2010). In Africa it is known to be established in both Kenya and South Africa, where there are large plantations of Eucalyptus , but it probably also occurs elsewhere on these trees. T. australis is often placed in a monobasic genus Isoneurothrips , because the forewing clavus bears six (instead of the normal five) marginal setae, and the pronotum has a strong sub-marginal ridge at the posterior. Such generic placement is unjustified. The number of claval marginal setae varies from five to eight in T. acaciae and from seven to nine in T. hoodi , and a pronotal posteromarginal ridge is developed in several of the larger species of this genus.

Diagnosis. Colour variable from yellow to extensively brown; body and legs usually yellow, tergites with brown area medially, X largely brown; antennal segments I and III yellow, remaining segments largely brown; forewings pale with dark setae, hind margin often shaded. Antennae 7-segmented, VII short, VI bullet-shaped. Ocellar setae III just within anterior margins of triangle, close to fore ocellus. Pronotum with 2 pairs of short stout posteroangular setae. Metanotum reticulate, median setae arising well behind anterior margin, campaniform sensilla present. Forewing first and second veins with almost complete row of closely set setae; clavus with 6 marginal setae. Tergite VIII with comb incomplete medially, about 8 teeth laterally; pleurotergites commonly with several discal setae; sternites with up to 30 discal setae.