Allothrips megacephalus Hood, 1908: 373.

Original reference: Hood JD (1908) New genera and species of Illinois Thysanoptera. Bulletin of the Illinois State Laboratory of Natural History 8: 361–379.

Family
Phlaeothripidae, Idolothripinae

Nomenclatural information 
https://thrips.info/wiki/Allothrips_megacephalus 

Diagnosis
Female micropterous or apterous; body color dark brown, with tarsi, tube and antennomeres I and II lighter. Antennae 7-segmented, antennomeres VII and VIII fused; antennomere III with 2 and IV with 2 sense cones. Head slightly longer than wide, eyes reduced to few ommatidia; dorsal surface with four pairs of capitate setae: one pair between eyes, one median postocular pair, one lateral postocular pair and a pair in the middle of head; maxillary stylets parallel to each other, about 1/4 to 1/3 of head width apart. Pronotum with 6 pairs of well-developed and capitate setae, including the posteromarginal pair; prosternal basantra present. Metathoracic sternopleural sutures present. Pelta wide, sculpture weak or absent; abdominal tergites II–VII with 1 pair of wing-retaining setae. Tube cone-shaped and short, anal setae longer than the tube, lateral setae absent. All legs similar in appearance, fore tarsi without a tooth.

Male apterous; similar to female but paler, with enlarged fore legs and a thick tarsal tooth. Pore plates absent.

Intraspecific variation
Micropterous and apterous forms are known, with the latter being more common; apterous specimens have even smaller eyes (about 6 ommatidia), ocelli and wing-retaining setae are absent.

Genus and similar species information
Allothrips is currently composed of 24 species, but some authors consider most of them subspecies of A. megacephalus and A. pillichellus. Members of this genus are usually apterous, their eyes are reduced to few ommatidia, they have only two sense cones on antennomere IV, and antennomeres VII and VIII are completely fused. The two species recorded in Brazil, A. brasilianus and A. megacephalus, can be distinguished by their colouration ( mainly brown in A. megacephalus, brown with yellow head, legs and tube in A. brasilianus) and size and position of the median dorsal pair of setae on head (short and almost in a line with the postocular setae in A. brasilianus; long, capitate and distanced from the postoculars in A. megacephalus).

Distribution around the world
Described from the United States, and recorded from Brazil (Cavalleri & Gonçalves 2022).

Distribution in Brazil
http://fauna.jbrj.gov.br/fauna/faunadobrasil/221116 

Life history
Lives in dead twigs and leaf litter, where it feeds on fungal spores. 

Economic importance
Not recorded.

References suggested
Hood JD (1908) New genera and species of Illinois Thysanoptera. Bulletin of the Illinois State Laboratory of Natural History 8: 361–379.

Stannard LJ (1955) The species and subspecies of North American Allothrips (Thysanoptera: Phlaeothripidae). Annals of the Entomological Society of America 48: 151–157.

Mound LA (1972) Polytypic species of spore-feeding Thysanoptera in the genus Allothrips Hood (Phlaeothripidae). Journal of the Australian Entomological Society 11: 23-36. 

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. 

Cavalleri A & Gonçalves S (2022) Novos registros e checklist das espécies de Thysanoptera do Pampa Brasileiro. Entomological Communications 4: ec04014: 1–3.