Generic diagnosis

Dark brown macropterous Phlaeothripinae, varying greatly in structure between sexes and body sizes. Head longer than wide, usually with stout setae on genae; mouth-cone pointed, maxillary stylets retracted to eyes, close together medially. Antennae 8-segmented; segment III usually with 10 or more stout sense cones, IV with 4 sense cones, VIII constricted at base. Pronotum with 5 pairs of major, capitate setae; notopleural sutures complete; major males with fore coxae greatly enlarged. Prosternal basantra absent, fema well-developed, mesopresternum sometimes complete in females, usually divided into three plates; metathoracic sternopleural sutures present but often not clear. Metanotum reticulate, reticles often with internal markings. Fore tarsal tooth present in both sexes. Fore tibiae sometimes with row of tubercles on inner margin. Fore femur with median tubercle, much larger in large males than in small males or females; inner apex of fore femur with tubercle in large male. Fore wings weakly constricted medially, with duplicated cilia. Pelta triangular, reticulate; tergites II‒VII each with two pairs of wing-retaining setae, also several accessory setae; tergite IX setae as long as tube; tube shorter than head, straight-sided. Male tergite IX setae S2 short and stout; sternite VIII without pore plate.

Nomenclatural data

Ecacanthothrips Bagnall, 1909: 348. Type species Acanthothrips sanguineus Bagnall, 1908 [= Idolothrips tibialis Ashmead], by monotypy.

There are eleven species listed in this genus, with the only species known from Australia described from different countries under 17 different names (ThripsWiki, 2022).

Australian species
Ecacanthothrips tibialis (Ashmead, 1905: 2)

Relationship data

This is one of several Phlaeothripinae genera related to the worldwide genus, Hoplandrothrips, but each of the known species of Ecacanthothrips has an unusually large number of sense cones on the third antennal segment.

Distribution data

The genus Ecacanthothrips is widespread in the tropics of Asia, but one species, tibialis, has become dispersed to many tropical countries. Specimens have been studied from India, Christmas Island, Thailand, Malaysia, Indonesia, Singapore, Sarawak, Timor Leste, and Hawaii, and a few individuals have been seen from northern Australia.

Biological data

Species of this genus are fungus-feeders on dead branches, sometimes forming large colonies. Judging from the variation in structure amongst the males it is likely that some form of male/male competition occurs in these colonies.

References

Okajima S (1983) Four new species of Ecacanthothrips from the Oriental region (Thysanoptera, Phlaeothripidae). Kontyu 51: 56–65.

Palmer JM & Mound LA (1978) Nine genera of fungus-feeding Phlaeothripidae (Thysanoptera) from the Oriental Region. Bulletin of the British Museum (Natural History). Entomology 37: 153–215.

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