Distinguishing features

Female fully winged. Body and antennae brown to dark brown, tarsi and apices of tibiae yellow; fore wings with base pale, brown medially, then pale brown distally but with extreme apex brown. Antennae 8-segmented; segments III & IV with elongate apical neck, each bearing long forked sense cone. 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 near anterior margin; campaniform sensilla present. Prosternal ferna complete; meso and metafurcal spinula well developed. Fore wing first vein with 4–5 setae distally, second vein with about 18 setae. Tergites I–VII with no sculpture lines between setal pair S1; 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.
Male micropterous, similar to female in structure, but bicoloured with pronotum yellow, also metathorax and abdominal segments I and IV–VII; tergites III–VII with craspedum of laterally directed slender teeth; IX without stout setae; sternites III–VII each with a pair of large pore plates.

Related species

Dichromothrips includes 18 species from orchids in the Old World tropics, and an identification key to 14 of these was given by Mound (1976). D. spiranthidis females are similar to macropterous females of D. australiae, but with less sculpture medially on the tergites, and with the apex of antennal segments III–IV more slender.

Biological data

Feeding and breeding on leaves, and sometimes on flowers, of various Orchidaceae (eg. Microtis unifolia, Prasophyllum wilkinsoniorum, Spiranthes sinensis, Thelymitra sp.).

Distribution data

Known only from southeastern Australia and New Zealand (AK/NN), where it has been collected in November, January, and February.

Family name

THRIPIDAE, THRIPINAE

Species name

Dichromothrips spiranthidis (Bagnall)

Original name and synonyms

Physothrips spiranthidis Bagnall, 1926: 104
Dichromothrips maori Mound, 1976: 256

References

Mound LA. 1976. Thysanoptera of the genus Dichromothrips on Old World Orchidaceae. Biological Journal of the Linnean Society 8: 245–265.

Mound LA & Walker AK (1982) Terebrantia (Insecta: Thysanoptera). Fauna of New Zealand 1: 1–113.