breviceps
breviceps antenna  
breviceps metathorax
breviceps prosternites

Generic diagnosis

Small, light brown, macropterous Phlaeothripinae, with head slightly wider than long, large eyes and long capitate postocular setae; maxillary stylets wide apart, not retracted to postocular setae. Antennae 8-segmented, but VII and VIII fused with suture between them visible ventrally; III and IV angulate medially with long stout sense cones, III with 2, IV with 3. Pronotum transverse, with 5 pairs of long capitate setae, anteroangular and midlateral pairs unusually close together; notopleural sutures incomplete. Prosternal basantra absent; ferna large; mesopresternum narrowed or absent medially, but fused to mesoeusternum laterally; metathoracic sternopleural sutures absent. Mesonotal lateral and metanotal median setae elongate and capitate; metanotum very weakly reticulate medially. Fore tarsal tooth absent. Fore wings not constricted medially, with duplicated cilia; sub-basal setae long and capitate. Pelta elongate triangular, recessed into anterior margin of tergite II; tergites II‒VII each with two pairs of sigmoid wing-retaining setae; tube shorter than head; tergite IX setae S1 and S2 weakly capitate, about as long as tube. Male sternite VIII without pore plate.

Nomenclatural data

Trichinothrips Bagnall, 1929: 604. Type species Trichinothrips branderi Bagnall, 1929, by original designation from two species.

There are seven species listed in this genus (Mound & Marullo 1996; ThripsWiki, 2021).  

Australian species
Trichinothrips breviceps (Bagnall), 1926: 550

Relationship data

This genus seems to have no obvious relatives among the Old World Phlaeothripinae. It is possibly of South American in origin and inadvertently introduced to Asia and Australia.

Distribution data

This genus was based originally on two species, each known only from a single specimen. One was from Sri Lanka and the other from Malaysia, but these were subsequently considered to represent a single species (Mound 1968). One further species is recorded from Java and five more from Central and South America, but again all are known only from single or from very few specimens, although colonies of T. breviceps are recorded from southern India (Seshadri, 1952). From Australia, two females identified as breviceps have been seen, one collected at Darwin and the other collected at Canberra (Mound & Tree 2022).

Biological data

Nothing is recorded of the biology of most species in this genus, although the first described specimen was stated to be "carnivorous on a psocid". Seshadri (1952) studied the biology of T. breviceps in southern India, demonstrating that larvae and adults all fed on the immatures and adults of Archipsocus that live under webbing on the bark of trees. The rarity with which the other species have been collected might suggest that they are all predatory on some small arthropods.

References

Mound LA (1968) A review of R.S. Bagnall's Thysanoptera collections. Bulletin of the British Museum (Natural History). Entomology Supplement 11: 1–181.