Palpada

Palpada is a genus of 85 neotropical and nearctic flower flies or hoverflies.
This genus is often colorful and bee-like. It is in the tribe Eristaliini containing dozens of genera. Common sister genera include Eristalis, Meromacrus, Eristalinus and Helophilus.
The genus Palpada is distinguished by:

Eyes with uniform pile.
Meron with fine pale hairs in front of or below spiracle.
Hind femur with basal patch of dense black setulae.
Cell r₂₊₃ closed before wing margin.
R₄₊₅ moderately to strongly dipped into cell r₄₊₅.

The larvae are aquatic and have a distinctive shape, usually being referred to as rat-tailed. The rat-tail is a breathng tube that allows the larvae to live in low oxygen water.