These flies are not from the government, but they are here to help you. Or they were, if their short lives haven’t already expired. I heard a quick mention of friendly flies on the radio the other day and had to look up more information. Turns out their numbers are tied to the population of tent caterpillars Ã¢â‚¬â€ the caterpillars that spin gauzy cocoons in your trees and then eat all the leaves.
Anyway, a rumor seems to persist that the government releases friendly flies to control tent caterpillar populations. To dispel that bit of misinformation, the state Department of Environmental Conservation puts this on their Web page about the flies: The DEC did NOT release these flies.
The flies attack the cocoons. More cocoons means more flies, which, probably, results in fewer adult caterpillars the next year.
Here’s a newspaper story about the whole thing.