Hover Flies

(Syrphidae), a family of dipterous flies of the suborder Brachycera. The flies are usually of average size (5–15 mm); less frequently they are large (up to 25 mm). There are about 4,000 species. They are found mainly in the tropics. In the USSR there are about 600 species. They fly well and often hover in the air. They are important in the pollination of plants, especially cultivated crops. Representatives of the various Syrphidae genera develop differently. Larvae of the genus Syrphus and other predatory members of Syrphidae live openly on plants, feeding mainly on aphids, thus benefiting the plant. Larvae of other genera (for example, Eristalis) live in water, feeding on decomposing matter and silt. The larvae of many genera are herbivorous; they live in the stems or bulbs of some herbaceous plants. The latter group includes small narcissus flies (Eumerus strigatus and E. tuberculatus), which are very harmful to onion bulbs. The larvae of some Syrphidae live in the nests of “social” Hymenoptera (bumblebees, wasps, and ants).