I happen to study/photograph insects as an amateur and can casually confirm the collateral damage pesticides have on insect life.

A common manifestation of it is to find lethargic insects. Bodily fully intact and seeming healthy, yet barely able to move. Insects normally skittish that you can simply pick up. I'm not talking about insects at the end of their life cycle or them being very cold. There's something very wrong with these individuals, I believe studies suggest their brains are messed up from the pesticides.