there are many good points in this thread. being cautious is a good very good practice. I will be honest 99% of the diet i feed to my frogs are insects that i personally breed. And i do believe this is the safest method. I just don't have the time to prob around and find bugs. not to mention i live in southern California and i am not sure i would trust any insects in this area. But where i lived in idaho there are several thousand acers of land that are not being used by people or civilization of any sort those are the places i would find wild insects to feed to my frogs. And if you do decide to use wild caught insects as feeders i would recommend avoiding area's with lakes and streams. this will reduce the chances of encountering parasites, poisons of all sorts, and of course the very dangerous chytrid.

And DVirginia, I spoke the to largest cricket breeder in the area. this guy sells to all major pet stores in the area. I was asking tips on breeding them and he said he feeds them veggies that a local farmer gives him that aren't up to standards to sell for human consumption. Not saying all breeders do this just saying the largest one in my area does. I even asked him if he has had issues with pesticides and he said he has had problems in the past.
And Namio, You are for sure right about removing the outer layer of the veggies being fed. It is a good practice to do for yourself as well. I know that farmed mammals and birds are irrelevant to breeding insects i was just trying to explain two different points and kind of got side tracked. I was making no parallel between the two subjects. although it may have seemed like it. I was in fact trying to explain that an animals movement Habits have little effect on whether they are safe to eat or not but i neglected the fact that this can not be compared to wild insects.
good posts everyone.