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

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Chloropids ( Synonyms: Oscinidae; Siphonellopsidae) are common, ubiquitous, small acalyptrate flies (length 1.5-5.0mm). Their biology is varied, and includes saprophages, gall inducers, egg predators, and a few parasites. Almost 270 Australian species have been described in 45 genera. The largest genera here are Apotropina, Cadrema, Gaurax and Chlorops .

The adults are of almost ubiquitous occurrence, and larvae, though still little known, appear to inhabit a wide range of habitats. Larvae of numerous species live within the young shoots and stems of grasses and other plants; these may be largely bacterial feeders.
In the Northern Territory, larvae of Anatrichus are associated with rice, but it is uncertain if they are the primary cause of damage. Larvae of Batrachomyia live beneath skin of frogs, feeding on blood. Gaurax flavoapicalis has been reared from both new and rotting swedes. Larvae of Gaurax spp. (with adults very like the last) live in spiders' egg-cocoons, while Gaurax tonnoiri has been reared from cocoon masses of sawflies and oothecae of mantids. Larvae of Gaurax luteohirtus are recorded as eating the eggs of Eurymela fenestrata (Hemiptera), and some species of Apotropina are parasites or hyperparasites within the burrows of fossorial Hymenoptera. Cadrema nigricornis flavus has been reared from stranded marine molluscs.


Characteristically, chloropids have a large triangular plate on the frons that is commonly polished. Postocellar bristles usually convergent (subparallel in some Chloropinae); fronto-orbital bristles usually weak, never with distinct proclinate and reclinate elements; prosternum with well-developed precoxal ridges; mesopleural bristle absent. Most members of the family have a characteristic curve in vein CuA.


Found commonly in all states, and in a variety of habitats, including rainforest and open forests.

  • Chloropidae, grass fly

  • Chloropidae

  • Chloropidae

  • Apotropina sp.