BT is Bacillis Thurengiensis and is supposed to be effective only on "worms" such as tomato horn worms, cabbage loopers and corn ear worms. It is a biological insecticide, found in the soil. One well known name is Dipel. It does really work on cabbage worms.
Squash bugs and squash vine borers are two different demons. The borers actually bore into the vine and kill off the whole thing very quickly; it just wilts like it was broken off at the base. They spend part of their life in the soil, and bore into the plant unnoticed by most gardeners. They are very difficult to eradicate.
The squash bugs eat the leaves and can kill the plant that way. Squash bugs hide in the leaf litter under the plant at night, and come out during the day. So you could maybe use an insecticide on the ground--shouldn't hurt the bees that way.
You might try putting DE (diatomaceous earth) on the ground, or on plants that are not blooming. It is a dessicant, and will dry out the insect and clog its breathing apparatus, I have been told. I use it in the chicken house and run to keep flies down and prevent mite infestations. It is finely ground diatom fossils, as natural and organic as you can get.
