what would this bug wiki provide that isn't already provided by troutnut.com?
The basic is that it'd be more PA centric. For instance, if you say Drunella Lata, troutnut will have great pictures and a good entemological rundown of the bug.
On this list, I'd imagine the pictures, either user supplied or just a link to troutnut's page on the bug. But it'd also include a list of streams where and when it occurs. For instance, I'd say I know it occurs on Penns Creek in June, morning hatch and dusk spinner fall. Someone else adds Oil Creek, someone adds BFC, and so on. In time you have a list of everywhere you can find the bug and when. You can go further and add local names, historical names, etc. For instance, someone adds that in SC PA they still call them Cornuta, in NC and NW PA they just call them BWO's (due to lacking other types of BWO's), but in central PA they differentiate them from the Baetis varieties by calling them large olives, late olives, or blackish olives, etc.
If you really want to get technical with the links and searches, you could have various lists cross reference each other. For instance, while on troutnut (and presumably our site as well), you can search by scientific or common name. But on ours, you could also search by stream, and get a list of all the bugs on that stream.
In essence, it's troutnut focused on PA, combined and cross referenced with good local, user generated hatch charts. With enough work, wiki participation and editing, it could be an amazing site!