Generic diagnosis

Medium sized, usually micropterous Phlaeothripinae. Head longer than wide, at least posterior half reticulate, postocular setae strongly capitate; maxillary stylets retracted to eyes, close together medially; mouth cone long and pointed, extending between fore coxae. Antennae 8-segmented, III with one sense cone, IV with 3+1 or 2+1; VIII not constricted at base. Pronotum almost as long as wide, with 5 pairs of capitate major setae; notopleural sutures complete. Prosternal basantra absent but chitinous islets large and robust; ferna relatively small; mesopresternum reduced to two lateral triangles; metathoracic sternopleural sutures long and narrow. Metanotum boldly reticulate. Fore tarsal tooth long; fore tibia often with a minute apical tubercle on inner margin, fore femora swollen. Pelta and tergite II reticulate; tergites II–VII each with two pairs of weak wing-retaining setae, lateral marginal setae long and strongly capitate; tergite IX setae S1 and S2 long and capitate; tube about as long as head width, anal setae long. Male with tergite IX setae S2 capitate but shorter that S1, sternite VIII with wide pore plate.

Nomenclatural data

Horistothrips Morgan, 1913: 36. Type species Horistothrips australiae Morgan, 1913, by monotypy.

There are five species listed in this genus (ThripsWiki, 2022).

Australian species
Horistothrips australiae Morgan, 1913: 36
Horistothrips platygaster (Karny, 1920: 39)

Relationship data

Despite being fungus-feeding, the species of this genus are probably not closely related to the Hoplothrips group. Moreover, the three non-Australian species listed in this genus are possibly not related to the two from Australia.

Distribution data

The two Australian species have been found in Eastern and Western Australia, but the other three species listed in this genus are from Fiji and from China.

Biological data

The described species are known from very few specimens, but there are many slides of unidentified specimens in the QDPI collection in Brisbane. These species are probably fungus-feeding on dead branches, but it is unusual to discover colonies on which to base studies of intra and inter species variation.

References

Mound LA (2008) Identification and host associations of some Thysanoptera Phlaeothripinae described from Australia pre-1930. Zootaxa 1714: 41–60.

ThripsWiki (2022) ThripsWiki - providing information on the World's thrips. Available from: http://thrips.info/wiki/ (Accessed 15.iii.2022)