Female macroptera. Body and antennae brown to dark brown, tarsi and apices of tibiae yellow; fore wings with base pale, brown medially, then pale brown distally. Antennae 8-segmented; segments III–IV with apex narrowed, bearing long forked sensorium. Head wider than long, with 2 pairs of ocellar setae; pair III about as long as side of ocellar triangle. Pronotum transversely reticulate, 2 pairs of posteroangular setae but external pair much shorter than inner pair; 2–3 pairs of posteromarginal setae. Metanotum with irregular transverse reticulation, median setae arising behind anterior margin; campaniform sensilla present. Prosternal ferna complete; meso and metafurcal spinula well developed. Fore wing first vein with 3–4 setae distally, second vein with at least 15 setae. Tergites I–VII with transverse reticulation across median area; VIII with regular comb of long microtrichia; X without longitudinal split. Sternite VII with 2 pairs of median setae arising well in front of posterior margin.
Female hemimacroptera. Forewing about 1.5 times width of pterothorax; metafurcal spinula weak; pronotal external posteroangular setae shorter than inner pair.
Female microptera. Forewing no longer than thorax width; tergal setae pairs S1 and S2 equally long.
Male microptera. Similar to female, uniformly dark brown; tergite IX without stout setae; sternites III–VII each with a pair of large pore plates.
Dichromothrips includes 18 species from orchids in the Old World tropics, and an identification key to 14 of these is given by Mound (1976). D. australis exhibits considerable variation in wing length, and some other structural details are also not constant, including the length and position of ocellar setae III and also the form of the metathoraci furcal spinula.
Known only from Australia.
New South Wales, Australian Capital Territory.
Feeding on leaves.
Pterostylis cycnocephala, P. nutans, P. pedunculata (Orchidaceae).
Dichromothrips australiae Mound
Mound LA. 1976. Thysanoptera of the genus Dichromothrips on Old World Orchidaceae. Biological Journal of the Linnean Society 8: 245-265.