Diceratothrips bicornis Bagnall, 1908: 194.

Original reference: Bagnall RS (1908) On some new genera and species of Thysanoptera. Transactions of the Natural History Society of Northumberland 3: 183–217.

Family

Phlaeothripidae, Idolothripinae

Nomenclatural information 

https://thrips.info/wiki/Diceratothrips_bicornis 

Diagnosis

Female macropterous; body color mainly brown, tube almost black with yellowish apex, legs knees and all tarsi yellow; antennae brown, with antennomere II yellowish, base of III and all of VIII paler; wings pale brown, base brown, both venations shaded with brown. Antennae 8-segmented, antennomere III with 2 and IV with 4 sense cones. Head longer than wide, dorsal surface weakly sculptured, with well-developed pairs of preocellar, postocular and median setae; lateral margins parallel, continuous with eyes and with two or three pairs of stout setae; maxillary stylets V-shaped, about 1/3 of head width apart, extending to base of postocular setae. Pronotum with four pairs of well-developed setae, anteromarginal and anteroangular pairs short, epimeral and posteroangular pairs elongate, midlateral pair very reduced or absent. Metanotum weakly sculptured, with one pair of thick median setae. Metathoracic sternopleural sutures present. Pelta triangular, with posterior angles extended and turned anteriorly, with irregular reticulation anteriorly and striate posteriorly; abdomen weakly sculptured, tergites II–VII with 1 pair of wing-retaining setae. Tube cylinder-shaped and slightly constricted apically, about 3.4x as long as basal width, without lateral setae. Fore legs slightly enlarged, fore tarsi with a minute tooth. Fore wings with over 20 duplicated cilia.

Male macropterous. Minor specimens similar to females. Major males with a longer head with sinuous lateral margins; fore femora enlarged and with multiple tubercles on inner margin, and with a posterior projection that seems to interact with a series of ridges in the fore coxae; tarsal tooth straight and long. Pore plates absent.

Intraspecific variation

Variations in size are common within and between populations. Very small males may have the “stridulatory structure” on fore legs reduced or even fully absent. Differences in the development of fore femora setae and coloration of antennomere III are also observed (Mound & Marullo 1996).

Genus and similar species information

Diceratothrips is a genus with almost 20 species, occurring in the Neotropical region and south of the United States. It has similarities with species of Diplacothrips, but can be distinguished from them by the presence of metathoracic sternopleural sutures. Males of Anactinothrips and Diceratothrips have a unique adaptation to their fore legs, with a series of ridges on the coxae and a posterior projection on the femora, which seem to work as a stridulatory structure or as a locking mechanism for the fore legs. Despite this unique structure, these genera probably belong to different evolutionary lineages, and Diceratothrips can be distinguished from Anactinothrips for having metathoracic sternopleural sutures, a triangular pelta, and short setae on metanotum and laterals of abdominal segments. Diceratothrips bicornis, D. cornutus and D. robustus have several morphological similarities, with D. cornutus being differentiated from the others by the presence of tubercles at the base of preocellar setae. The other two species are not clearly distinguished, and may represent a single but highly variable and distributed taxon.

Distribution around the world

Described from Brazil, and widely distributed all the way through Mexico.

Distribution in Brazil

http://fauna.jbrj.gov.br/fauna/faunadobrasil/53516 

Life history

Lives in dead leaves and twigs, where it feeds on fungal spores.

Economic importance

Not recorded.

References suggested
Bagnall RS (1908) On some new genera and species of Thysanoptera. Transactions of the Natural History Society of Northumberland 3: 183–217.

Mound LA & Palmer JM (1983) The generic and tribal classification of spore-feeding Thysanoptera (Phlaeothripidae: Idolothripinae). Bulletin of the British Museum (Natural History). Entomology 46: 1–174.
Mound LA & Marullo R (1996) The Thrips of Central and South America: An Introduction. Memoirs on Entomology, International 6: 1–488.