Q.Pepper plant problem
I live in Prescott,AZ. I have noticed what looks like little white strings on the underside of the foilage on my pepper plants. I can’t see any visual pests. What do you think this might be?
It sounds like some kind of insect, although what you mean by "little white strings" might be different from what I think you mean. Spider mites leave webbing that is almost invisible; mealy bugs might look like little white strings to some; white fly larvae might look like very short white strings; leaf miner trails might be described as strings. One way to be sure would be to take some leaves to the Extension Service, where they could identify for you. This link will help you find one:
https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm