Potato pest populations are high in the Northwoods
The Colorado Potato Beetle and Potato Leafhopper have arrived, and their populations are at season highs.
The Colorado Potato Beetle chews leaves to the vein on potato crops, and its numbers are currently high in Wisconsin. Each year, the beetle adults overwinter and lay eggs in May and June. Their young are beginning to mature, and will soon be causing damage to potato crops, especially those already weakened by high temperatures. It’s very important for potato growers to control this first generation early; the second generation later in the summer will be even more disastrous to potato plants if early sightings are left untreated.
The Colorado Potato Beetle can be controlled with abamectin (Agri-Mek, Abba, Reaper, Athena, etc.), chlorantraniliprole (Voliam Xpress), novaluron (Rimon), rynaxypyr (Coragen), spinosad (Blackhawk, Entrust, SpinTor), or spinetoram (Radiant). In the coming week, it is recommended that any of the former products be used as a series of two successive foliar applications, spaced seven to 10 days, but should not exceed the season total maximum active ingredient specified on the label.
The Potato Leafhopper sucks sap and nutritious juices from potato plant leaves; this pest does not overwinter in Wisconsin, but arrives each spring, blown in on winds. The strong winds preceding fronts that are continually pushing through the area bring high numbers of traveling leafhoppers, and they will continue to be a prevalent pest all summer. Populations continue to grow after they’ve arrived, and can cause severely stunted growth, leaf yellowing and browning, and even plant death if left uncontrolled. Dinotefuran (Scorpion), carbaryl (Sevin), acetamiprid (Assail), thiamethoxam (Actara, Cruiser), malathion, and imidacloprid (Provado) insecticides can be applied per label directions and UWEx recommendations (found at http://learningstore.uwex.edu/assets/pdfs/A3422.PDF) to control this pest.
For more information, call Horticulture Assistant Marissa Hatlen at the UW-Extension at (715) 365-2750, email [email protected] or visit the lower level of Rhinelander-Oneida County Airport.