I've had good luck with Castrol SuperClean removing bugs, and lots of other stuff for that matter..."Purple Power" is pretty much the same stuff... But beware, this stuff is super-strong, it's basically oven cleaner in a gallon jug. It's a stupendous de-greaser. So good in fact that if you use it full strength with no gloves it'll suck all the natural oils out of your hands. It'll make white fiberglass yellow (it does go back to white)...
Anyway, the stuff seems to dissolve bugs too. Give it a try. With caution!