Ground Nesting Wasp Dust

Any kind of dust that control bees will work to kill ground nesting wasps and bees if inserted in and around the nesting hole. Apicide is a good choice as are others. Treatment of a ground nesting wasp hole is risky and should be handled by a professional.

NulliFly

Small flies are often drain or fruit flies. Here is one company that addresses these buggers with natural bacteria that eat away at the slime and grime that causes the breeding of these flies in the drains. They have a foam product that I think is one of the best ways to treat the drain as it expands and coats the drain walls where this slime builds up.