Sorry, I forgot you guys don't know.... we moved this year. Had whiteflies on the tomatoes every time I got some or planted seeds. Tomatoes only. No matter the season or weather. It's very humid down there.
Moved up here (2 zones north) & low humidity here.
Got some tomato seeds, planted them, & yep, you guessed it --- whiteflies.
Nature's cycles --- must be the years of whiteflies on tomatoes in the deep south of the U.S. This too shall pass.
Oh, I know what hoverflies are now. I had not heard them called that. A generic term for all those who do that. I thought you guys were talking about something specific. Like black flies. I have heard of them but have never encountered them. I understand they have a nasty bite which draws blood & can be a real pain in the *&%#.