Overwintering females emerge in late April and lay a cluster of bright, yellow eggs on recently emerged potato plants. Larvae mature in about 3 weeks and pupate in the soil. After another 10 days, adult beetles emerge, mate and lay more eggs.
Both larvae and adults of this insect feed on potato (as well as tomato, eggplant, and pepper), causing extensive loss of foliage and reducing yields. Control strategies are varied and include:
– Hand picking: Useful for small gardens where plants can be checked a couple of times a week. Dropping beetles and larvae in a container of soapy water will lead to their demise.
– Floating row cover: This material can be placed over the planting and act as a physical barrier to the insects. Be sure to seal the edges. It is sometimes suggested to leave the floating row cover in place during the growing season because potatoes do not need to be pollinated to produce tubers. Often, this is not practical because it interferes with weed control.
– Insecticides: A number of products are registered including spinosad (Fertilome Borer, Bagworm, Leafminer and Tent Caterpillar Spray and Bonide Colorado Potato Beetle Beater Concentrate), permethrin (numerous trade names) and lambda- or gamma-cyhalothrin (Bonide Beetle Killer, Spectracide Triazicide). (Ward Upham)
