Your thoughts on Bt...is it safe?
A friend of mine is having a major battle with white butterflies. She was about to haul out the Derris Dust when I went on the "rotenone...bad...off approved organic lists..." spiel and recommended she try Bt instead.
She was very curious about its environmental safety and potential for harming beneficial and indigenous Lepidoptera. I had to admit I had no idea and hoary old truisms like "no free lunch" started playing in my head. I've avoided using it, as I'd rather squash things and not kill off all the parasitic wasp dinner, but I hadn't considered any possible wider implications
She's got a Masters in some sort of biology, so I have to take her concerns seriously.
There's a fair amount of "Bt's bad" stuff online, but I'd be very interested to read your thoughts.