Earlier quoted context omitted.
They release enzymes necessary for the spice/acid production. The acid counteracts those enzymes. If you cut open peppers, you can see the black veins which were bit by bugs, those are the ones containing the carbon acid. A better way to protect them against virusses but not against bugs that won't harm them is by combining the top of peppers with the root of potatoes, and by using moss to heal the cuts where you com…
The bites themselves don’t cause the plant to produce more capsaicin. It’s natural selection - plants in areas with lots of insects end up producing more capsaicin as a means of protecting themselves. They are hotter, and insects will not bite them as a result. Happy to be proven wrong if you have sources saying otherwise, but I’m quite certain this is the science behind it.
There is every reason to expect that a plant's defenses against predation will be more active the more predation it experiences.