I'm not sure about the bugs…I suspect about any good insect killer will work…I used JB products for my rot I found in my tool compartment on the opposite end of the trailer…I dried it out good ( 3 days ) with a fan and sprayed it with the first part of the JB kit,let it dry for a day, then I used part 2 which mixes easily in your hand (it also comes in two parts, epoxy based), and then you work it into areas you want to rebuild) ….It worked well for me….It can then be drilled etc….There are other products out there that may be better but I used JB products, because of my experience with them in the shop in other applications…Good Luck...
Dave….