Generic diagnosis

Medium to large, brown to bicoloured, macropterous Phlaeothripinae. Head longer than wide, slightly produced in front of eyes; cheeks sometimes with a small tooth behind eyes; genae usually with 2 pairs of setae; postocular setae arising well behind eyes; mouth cone short, stylets not extending to postocular setae. Antennae 8-segmented, segment III with 3 sense cones (rarely 4 or 2). IV with 4 sense cones, Vlll not constricted at base. Pronotum elongate in females, transverse in males; anteromarginal setae very small. Prosternal basantra absent; ferna large; mesopresternum of 2 triangles; metathoracic sternopleural sutures long and slender. Mesonotal midlateral setae acute, stouter than median metanotal setae. Fore tarsal tooth large in both sexes; fore tibia apex sometimes drawn out close to tarsal tooth; fore coxae large; fore femora usually expanded. Fore wing slightly narrowed medially. with 15–30 duplicated cilia. Pelta variable, usually as wide as long: tergites II–VII with two pairs of sigmoid wing-retaining setae; tergite IX setae less than half as long as tube, setae S2 usually short and stout in female as well as in male; tube with longitudinal ridges in basal third, apex weakly constricted, anal setae less than half as long as tube. Sternites with about 30 discal setae arranged irregularly or in two transverse rows; specialised areas of reticulation not developed. Males smaller than females, without pore plate on sternite VIII.

Nomenclatural data

Sacothrips Moulton, 1968: 112. Type species Sacothrips bicolor Moulton, 1968, by monotypy.

There are seven species recognised in this genus.

Australian species
Sacothrips bicolor Moulton, 1968: 113
Sacothrips catheter Mound, 1971: 94
Sacothrips corycidis Mound, 1971: 94
Sacothrips galbus Mound, 1971: 95
Sacothrips ingens Mound, 1971: 96
Sacothrips mantoideus (Girault, 1927: 1)
Sacothrips milvus Mound, 1971: 96

Relationship data

This is one of three genera that are found only on the leaves of Geijera, and that possibly represent a single evolutionary lineage. Males of the species of Sacothrips lack a pore plate on sternite VIII, and in both sexes the posterior margin of the head is not prolonged medially.

Distribution data

An Australian endemic that is known only from the western slopes of the Great Dividing Range in eastern Australia.

Biological data

All species in this genus breed only in rolled-leaf galls on Geijera parviflora [Rutaceae], and some of these species are certainly inducers of such galls.

References

Mound LA (1971) The complex of Thysanoptera in rolled leaf galls on Geijera. Journal of the Australian Entomological Society 10: 83–97.