One might have thought that any self-respecting insect would have closed down shop for the year, but this is not the case. Yesterday as I wandered around my yard, I saw a dragonfly (a darner), a bumble bee (Bombus vagans), many wasps (aerial yellowjackets) and at least four species of hover flies.
The hover flies are also known as flower flies in that (as adults) they feed on the nectar and pollin of flowers. Many of them also look somewhat like wasps or bees—a defence against the birds that would eat them. But, they are flies that neither sting nor bite.
Below are three different hover flies seen yesterday.
Hover fly on hawkweed. Things to notice: the widely separated eyes show this to be a female; unlike many insects, flies have only two wings; the vestigial second set of wings has been reduced to the halters—the knobbed filaments just behind the wings that are used as a vibrating gyroscope to provide balancing information.
Hover fly on cinquefoil. Again, the eye separation shows this to be a female.
Hover fly on aster. The large closely spaced eyes show this to be a male. The males use their large eyes to help them find the females.
Thanks Alistair, informative as well as great pictures.