There are a couple of products designed to help control these bugs. One is "Bug Out" and the other "Bug Away." Ask a dealer.

These bugs actually use a primitive lung on their abdomen. They trap a bubble of air and use it to breath. The products reduce the surface tension of the water so that bubbles can't form and the critters drown. Generally what happens is that they will fly (yes, they fly) into the pool and try to trap a bubble. If they can't they will try to fly away. The ones in the pool will drown. Either way, the idea is to interrupt the breeding cycle and they will go away. You can scoop out the dead ones, let the skimmer get them or your auto cleaner.

The small ones are generaly just an unsightly nuisance, the big ones are the "mamma" and will bite. They can live in highly chlorinated water. I have found them inside floating chlorinators happily sitting on the tablets.