Food with bugs in it was cooked uncovered in my oven. Do I need to kasher my oven? What about utensils used to serve the food? What about the plates? Is the cooking also a sin, or just the eating?
Bugs will not make your utensils trief because they give off a negative taste. Although we may not eat them, in retrospect if they got on to utensils they will not prohibit them.
Shuchan Aruch 103-1