Research demonstrates the moderate efficacy of Cannabis as a repellent crop or botanical pesticide. We are faced, however, with a paradox: some of the pests controlled by Cannabis are also known to attack hemp and marijuana crops. If Cannabis serves as an effective pesticide, then how can the pests infesting Cannabis survive?>>>
The bugs in question are pests found in Europe and Asia, marijuana's native habitat. It was brought to America by Europeans IIRC.
And...One of the most destructive pests of hemp is the corn stem borer moth (Ostrinia nubilalis Hb.), known in North America as the European corn borer.
It sure isn't killing the borer moth.>>>
Give it a few million more years to evolve.