There is an invasion of HOVERFLIES this season and although a bit annoying, they are harmless but beneficial.If you have these flying insects in your garden, I bet you wouldn’t have aphids this year. My roses are usually covered and they have none. It is actually the larve that hits the aphids as they are predatory. The adults feed on nectar and pollen. These guys won’t stick around forever and will probably be gone in a few weeks, but they ate fascinating to watch and my.roses and strawberries.are very happy they are here, even for a short while.