MN Fruit & Vegetable IPM News - Vol. 1, No. 11

Potato Leafhopper (PLH): In snap beans, adult PLH/sweep increased dramatically this week with populations as high as 4/sweep, 4-8 times greater than the threshold, depending on snap bean growth stage. Nymphs are still present but populations have decreased somewhat due many nymphs maturing to adults. PLH populations and damage from PLH can vary from field to field and on leaves within a given plant. We have included a picture of light puckering/leaf curling that signifies the beginning of significant PLH damage on snap beans. As populations build or are not managed the damage continues to develop and the leaves begin to show moderate to severe puckering/curling, and eventually begin to turn yellow on the leaf margins as illustrated in the 2 nd picture. Populations of nymphs will continue to be present in snap bean fields until they develop in to adults. However, adult populations may still be variable based on weather events that move through an area.

In alfalfa, adult PLH counts have increased from 0.25/sweep to 1/sweep. This remains below threshold as most alfalfa is beginning to flower or has already been cut. But this provides further evidence of an area wide increase in PLH populations.

European corn borer (ECB): The univoltine ECB flight at Rosemount has remained low this week with a high of 2 moths per night caught in the BLT (see graph below for multiple locations).

Corn earworm (CEW): We continue to see very low CEW trap catches across the state. For additional information see the 2004 Moth Flight site for up-to-date information on moth flights (http://vegedge.umn.edu/2004/moth.htm ).

Western Bean Cutworm (WBC): This week WBC trap catches remain low with 2-3 moths being caught per night. Recommendations for WBC in Minnesota sweet corn would be a threshold of 2-3% of the plants with WBC egg masses, from tassel through silk.

Cabbage looper (CL): Trap catches and plant samples for CL remain low at Rosemount with only 1 CL moth captured this week and only 2 CL eggs found in 30 plant samples. In addition, we have not observed significant larval infestations of either imported cabbageworm or diamondback moth.

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ACKNOWLEDGEMENTS

Co-Editors: Bill Hutchison, Department of Entomology, University of Minnesota, hutch002@umn.edu
Jeanne Ciborowski, Minnesota Department of Agriculture, Ag. Resources Division,jeanne.ciborowski@state.mn.us
Suzanne Wold-Burkness, Department of Entomology, University of Minnesota, woldx018@umn.edu

The Newsletter is published weekly from May through August, cooperatively, by the Minnesota Department of Agriculture (MDA) and the University of Minnesota (U of MN). Reports are posted on the U of MN and MDA web sites on Fridays. If you have suggestions and/or comments, please send your contributions by 4 p.m., Tuesday to Jeanne Ciborowski, 651-297-3217, jeanne.ciborowski@state.mn.us , MDA, 90 W. Plato Blvd., St. Paul, MN 55107-2094. You can access the Newsletter at the U of MN web site in htm. format at: www.vegedge.umn.edu/MNFruit&VegNews/mnindex.htm and at the MDA web site in pdf. format at: www.mda.state.mn.us/biocon/fruitreports/default.htm

Partial funding for this publication is provided through partnership agreements with the Minnesota Fruit and Vegetable Growers Association and the United States Department of Agriculture – Risk Management Agency (RMA) and the RMA Community Outreach and Assistance Partnership Program. These institutions are equal opportunity providers.

DISCLAIMER

References 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 manufacturer directions.

Last Revised July 22, 2004.
The University, including the Minnesota Extension Service, is an equal opportunity educator and employer. ©1999-2004 Minnesota Extension Service, University of Minnesota. All rights reserved. Contact copyright@extension.umn.edu for information on reproduction or use of this material.