On small clumps of mint, it is feasible to remove the beetles and their larvae by hand.
For more extensive infestations, it may be necessary to apply a pesticide. An organic insecticide, pyrethrum, (Py Spray Garden Insect Killer, Scotts Bug Clear Gun for Fruit & Veg, Doff All in One Bug Spray, or Growing Success Fruit & Veg Bug Killer) can be used on mint to control pests. This short persistence pesticide should deal with young larvae but may be less effective against the adult beetles. Other pesticides approved for use on outdoor edible herbs are lambda-cyhalothrin (Westland Plant Rescue Fruit & Vegetable Bug Killer) and deltamethrin (Bayer Ultimate Fruit & Vegetable Bug Killer). The minimum period that needs to be left between treatment and using the leaves is one day for pyrethrum and seven days for lambda-cyhalothrin and deltamethrin.