Eristalinae (or Milesiinae) are one of the four subfamilies of the fly family Syrphidae, or hoverflies. A well-known species included in this subfamily is the dronefly, Eristalis tenax.
Species in this subfamily are often misclassified as bees instead of flies due to their exceptional Mimicry, especially to resemble Honeybees (family Apidae). The best strategy for proper identification is to look at their eyes and wings and compare with fly morphology, to determine membership of family Syrphidae and/or of order Hymenoptera.
This subfamily has the widest range of larvae habitat of any in Syrphidae. Larvae live in sap trails, under bark, in rot-holes in trees, in decaying organic material such as dung and compost, and in shallow aquatic environments. Most larvae feed on decaying organic debris. They are filter feeders in many kinds of aquatic media. They purify water by filtering microorganisms and other products. Some feed on bulbs and are considered garden pests.
Certain species in Eristalinae live as scavengers and take shelter in the remains of other insects, while others, like Volucella, are Parasitoids and live in wasp or bee nests. Some other species are found to be leaf miners and tunnel inside the stems and roots of plants. Additionally, males of this subfamily typically employ dual mate-seeking strategies to find females, most commonly patrolling blossoms and waiting near potential sites where females could lay eggs.
