Neem oil is effective against the young Colorado potato beetle larvae, but it is less effective against large larvae and adult beetles. Neem breaks down rapidly and must be reapplied frequently. To help manage Colorado potato beetle while using environmentally friendly neem, plant resistant varieties, rotate crops and manually remove larvae and adults from leaves.
About this Author
Elizabeth McNelis has been writing gardening, cooking, parenting, and homeschooling articles from her St. Petersburg urban homestead since 2006. Her work has appeared in “The Perspective,” a homeschooling newsletter distributed in Pinellas County, Fla., and on her blog entitled “Whatever!” McNelis holds a bachelor's degree in professional and technical writing from the University of South Florida.