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

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A common, widespread family of flies, many with characteristic yellow markings on the body. The adults are swift fliers, and many species habitually hover, apparently motionless, in the air; hence their vernacular name of 'hover fly'. Over 5,500 species have been described worldwide, and just over 150 species have been described from Australia.

In warm, sunny weather, syrphids are a common sight, either on the wing or visiting blossom, and they are important pollinators of plants. Certain larvae (Syrphinae) are also beneficial, being important predators of aphids, but a few species of Eumerus are injurious to plant bulbs. Most larvae are maggot-like in appearance, living in rotting vegetation or fruit, or in liquid media; among the last are the 'rat-tailed maggots' of Eristalis spp., which are common in drains. The extraordinary larvae of Microdon spp. are oval and convex dorsally, soft and flat ventrally, and were originally described as molluscs! They are found in ants' nests, where the larvae live as scavengers or predators. Adults are pollinators of major significance to agriculture.


Like other lower cyclorrhaphans, syrphids lack a ptilinal suture, and they also have a long cell cup, like pipunculids. Some are stoutly built, closely resembling bees or muscoid flies; others (e.g. Ceriana, Allobaccha ) are quite remarkable Batesian mimics of stinging Hymenoptera, with waisted abdomen and appropriate markings. Psilota rubra even flies in association with the bee that it mimics. The wing venation is characteristic: vein M1 is turned forward to meet R4+5, and they often have a vein-like thickening, or vena spuria, between Rs and M.


In Australia, the family seems to be rather poor in species, and may be a relatively recent element of the fauna. Quite a few of our species (some 25, in nine genera) also occur in other countries. Some are obviously recent immigrants (e.g. the cosmopolitan 'drone fly', Eristalis tenax ), but others belong to wide-ranging species, or perhaps species-complexes, principally Oriental in distribution. The dominant genera in Australia are Ceriana , Microdon , Melangyna , Simosyrphus , Eristalis and Psilota , the last being poorly represented in other countries but relatively abundant here.

  • Microdon sp.

  • Ischiodon scutellaris

  • Syrphidae

  • Syrphid (hover fly)

  • Syrphidae

  • Eristalis sp.

  • A wasp like Syrphidae

  • Syrphidae larvae

  • Syrphidae