Bee flies require a second look
A lot of honey bees have been working the oregano in the last few weeks, but one day I noticed a bee that didn’t look quite right. It was slightly bigger than the rest and held its wings at a funny angle. Curious, I looked more carefully and realized it wasn’t a bee at all, but a fly.
In the past I would have assumed this was just a weird honey bee and not bothered to look further. But as I’ve studied pollinators more and more, I’ve come to realize the natural world is brimming with look-alikes—insects that mimic the appearance of other insects, especially bees.
The insect I saw is known as a “bee fly.” It is in the very large Bombyliidae family in the order Diptera. The adults feed on nectar and pollen, which makes them pollinators. The female lays her eggs in the nests of other insects, such as beetles, wasps, and solitary bees. When the eggs hatch, the newborn larvae eat the developing pupae of the host insect. How friendly.
There are about 5,000 known species of bee flies, and scientists suspect there are many more that haven’t yet been described. For the most part, the species in this family are poorly understood—mostly because they live singly and never appear in large groups or clusters.
Two things to look at when trying to distinguish between a fly and a bee are the wings and the antennae.
- Bees have two pairs of wings and flies have one pair. This can be tricky, however, because a bee’s wings hook together so they move as a unit. Often the two pairs look like one pair.
- A bee antenna is elbowed or bent. Fly antennae are often short, stubby, or extremely thin and hair-like.