Our county has a mosquito abatement service. Technicians come around during mosquito breeding season, sample skeeter habitat for larvae, and then add mosquito dunks, Bacillus thuringensis (sp?), cakes to the water.
Never have they found a single larva in in our fish pond. They do capture occasions wigglers in our sewage.lagoon.
I'd have to imagine that bt dunks could solve your larvae problems in your ponds without fishes.
