The fighting wasn’t even two bugs but I will ignore this fact. The answer is that it should be legal and is. However, there are probably all sorts of regulations about what animals you are allowed to keep in your home, etc. This is where we need some work to reduce and eliminate these regulations.
From everything that I was able to find, it appears as though it is legal, along with cock fights and dog fights. In the case of bug fights specifically, it appears as though one can actually buy bugs from vending machines, as well. It’s pretty disgusting, but then most people are pieces of shit. ^