The adult is a fly that mimics the coloration of wasps; it often hovers during flight (A). The eggs are white with a stippled sculptured surface (B). The larva (C) is a maggot of variable color (gray, yellow, orange, green or a combination of these colors). It is found among aphid colonies, often co-existing with other predators such as the gall midge.
Note: Hover flies are sensitive to several broad-spectrum insecticides, especially the organophosphates.
Numerous species have been identified in apple orchards. The hover flies are both pollinators (adults) and predators (larvae). In particular, hover flies help to maintain aphid populations at a low level.
The hover flies can be confused with some wasps, but they have larger eyes and are without the narrow "waist," as well as having only one pair of wings. The wasps have two pairs of wings, are generally larger and may have a sting.
The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.