In this issue:

Sweet Corn

Snap Bean

Strawberries…brief alert for spider mites

Sweet Corn Insect Update

Bill Hutchison, Eric Burkness, Robert Koch & Patrick O’Rourke, Dept. of Entomology, University of Minnesota

The 2nd generation flight of the European corn borer (ECB) is now underway at Rosemount (22 moths/night since July 27th), indicating the flight should also be underway throughout much of southern Minnesota. Fresh ECB egg masses are now common at Rosemount (Dakota Co.) on sweet and field corn; in one fresh-silking sweet corn, 5% of the plants had egg masses. Corn earworm (CEW) flights appear to have tapered off during the past week at most MN locations (see graphs). However, trap catches in Rosemount (Dakota Co.) and Owatonna (Steele Co.) locations are increasing. Western bean cutworm flights continue to be low in MN, compared with NW Iowa, where several traps have now exceeded 1,500 - 2000 moths/night. In Minnesota, maximum WBC moth catch reached 45 at LeSueur and 385 at Lamberton. All sweet corn now in the late tassel (spike or open tassel) to early silk stages will be attractive for egg-lay and should be protected (treated with insecticide). See earlier issues of the MN Vegetable IPM Newsletter for more information on treatment recommendations, including tips for organic growers. Again, Bt sweet corn will not need to be treated for ECB; if CEW is present (e.g., >10 moths/night for 2 or more nights in a pheromone trap), at least one spray will be needed (early silk) to ensure maximum ear protection from this pest.

Co-Editors: Bill Hutchison, Department of Entomology, University of Minnesota, hutch002@tc.umn.edu
Jeanne Ciborowski, IPM Program, Minnesota Department of Agriculture, jeanne.ciborowski@state.mn.us
Cindy Tong, Department of Horticulture, University of Minnesota, ctong@extension.umn.edu
Production Editor: Suzanne Wold, Research Assistant, University of Minnesota, woldx018@tc.umn.edu

Disclaimer
Reference to products in this publication is not intended to be an endorsement to the exclusion of others which may have similar uses. Any person using products listed in this publication assumes full responsibility for their use in accordance with current directions of the manufacturer

Last Revised August 2, 2002.
The University, including the Minnesota Extension Service, is an equal opportunity educator and employer.©2002 Minnesota Extension Service, University of Minnesota. All rights reserved. Contact copyright@extension.umn.edu for information on reproduction or use of this material.