For the first time I have experienced an invasion of a small white fly. half the size of an aphid. They first appeared in my heated greenhouse on my Roma tomatoes. They didn't seem to bother the tomatoes but came up in clouds when the bush was moved. Next they appeared on my bush beans [close to the greenhouse] and then on everything in proximity. I have never seen them before. A woman 25 klm away to whom I gave some tomatoe plants experienced the same thing. The bush beans I noticed instead of turning yellow at the end the leaves turned blackish.