Vikcreated a 3D-printed bug-repellent and uploaded the 3D file to Thingiverse:
Cabbage white butterflies are antisocial when they're laying their eggs. So if you stick up decoy butterflies, you can scare them off your crops. It's slightly oversize so it looks more intimidating to butterflies. Feel free to evolve the design.
Ignore butterflies attempting to mate with your decoy. They are stupid males and will not be laying eggs.