What Bug Is That? The guide to Australian insect families.

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Adults are most often found feeding at flowers (e.g. Hibiscus, Santalum ). Larvae of Gymnochiromyia have been found in bat guano in caves. In other countries chyromyid larvae live in rotting wood and other decaying plant material and also in dung piles below bird roosts.


These very small or minute and mostly yellow flies typically have the following features:

Three or more orbital bristles, all reclinate or the anterior one sloping inwards; postocellar bristles convergent; vibrissa distinct or not well differentiated from peristomial setulae; anepisternum bristled; wing with cells bm and cup completely enclosed or almost completely enclosed; veins A1 and CuA2 sclerotised, but not reaching wing margin; tibiae without differentiated preapical dorsal bristles.


Chyromyids are found nearly worldwide. Four species in the genera Aphaniosoma , Gymnochiromyia and Chyromya occur in Australia. The subfamily Nannodastiinae, which includes some of the smallest acalyptrates, lives on Christmas Island, in Papua New Guinea and on other tropical coasts, perhaps including northern Australia. They are sometimes treated as a separate family, differing from typical chyromyids in having long bristles on the anterior margin of the first flagellomere, in the dorsally displaced posterior notopleural bristle and in the absence of the postocellar bristle, alula, cell cup and vein A1+CuA2.

  • Gymnochiromyia sp.