Colorado potato beetle

Asked July 5, 2020, 6:58 AM EDT

Worst ever infestation. Liquid Sevin and Sevin dust just aren’t enough. They have migrated from potato’s to tomatoes and even young asparagus ferns. Any suggestions?

Kent County Delaware

1 Response

The Colorado potato beetle is an incredibly difficult pest to control because subsets of their populations are resistant to some insecticides. It is difficult to determine which pesticides a particular population is resistant too prior to management efforts. You potentially have a resistant population. Other products you could try are insecticides called pyrethroids (their active ingredient ends in "-thrin") and these are commonly available at garden centers and box stores throughout the area. Another product you could try is an insecticide that has an active ingredient called spinosad which is also commonly available. Shaking the beetles off into a bucket of soapy water or hand picking off the larvae or adults you encounter is another option (although more time consuming). Smashing eggs found is another strategy but takes time to locate the eggs.