Adult hoverflies can look superficially like wasps but have only 1 pair of wings and very short antennae. The adults feed on nectar and pollen, and so are often seen on flowers (or hovering over them prior to landing). The females lay their eggs close to aphid colonies, on which the larvae feed. The pupal stage is immobile, somewhat pear-shaped, and normally found on the same plant on which the larva developed.
Beneficial of the Month material courtesy of NMSU ACES:
Pocket Guide to the Beneficial Insects of New Mexico