Squash Vine Borers are similar to the Snowberry and Hummingbird Clearwing moths in that they have clear wings and can hover over plants while seeking nectar. A shutter speed of 1/5000 sec was used to capture this image.

Squash Vine Borers lay a single egg near the base of a plant, usually in the squash family. The larva develop inside the stem and block the flow of water to the plant, causing the leaves to wilt and yellow. Needless to say, this guy is probably one you do not want around if you are growing squash, pumpkins, or zucchini. However, I gave up on growing squash because my healthy population of grey squirrels almost always get to the fruit before it is mature, so I am not too concerned for my gardens.

Adults feed off nectar. Based on the large number of google images that depict the Squash Vine Borer seeking nectar from milkweed, milkweed flowers appear to be a favored source.