Looks a bit like a sweat bee, but I have both and this isn't a sweat bee. They are smaller than sweat bees and are more metallic, fly all over the plants, but show no evidence of munching. Seem to be harmless, but I would be interested in knowing more of their feeding/pollinating behavior.
Looks like a member of a group of flies commonly called long legged flies (Family Dolichopodidae). It seems most are shades of green or gold/copper color and are beneficial.
"Dolichopodids occur in diverse habitats; larvae are commonly found in moist soil and under tree bark and adults are often abundant near streams, and are found on foliage, tree bark, and flowers of various plants. Both larvae and adults are predaceous on many other insects and small arthropods, including mites, thrips, psocids, aphids, and other insects larvae. The maggot like larvae of the long-legged fly are found in such habitats as soil, rotted vegetation, mud, and under bark. Most are predators or scavengers."1
at first, this growing season, i would have severe aphid breakouts. i treated them with the basic soap/water mixture, and never had more trouble that 2 or 3 lost leaves from the buggers. but, i haven't had to spray in a good while, and the most aphids i've seen are 1 here, 2 there...
but, i have had a ton of these. and a good bit of ladybugs. and a huge garden spider. and they are all staying stuffed and happy.
That is the name of the game IMO. A person should not want an absence of pests, but rather a balance between beneficials and pests. That way the pests don't eat too much of your favorite plants, and at the same time, beneficials have enough to eat thereby staying and multiplying in the yard and garden areas.