Eristalis

Eristalis is a large genus of hoverflies, family Syrphidae, in the order Diptera. One of the more common species in the genus, Eristalis tenax is also known as the dronefly, because it bears a superficial resemblance to honeybee drones. Droneflies and their relatives are fairly common generalist pollinators, the larvae of which are aquatic, and breathe through a long, snorkel-like appendage, hence the common name rat-tailed maggots.