MN Fruit & Vegetable IPM News - Vol. 1, No. 3

When temperatures rise above 65ºF, you should start watching for clipped buds. The traditional advice has been that weedy fields with a history of clipper damage should be treated when temperatures get into this range. The old threshold is 0.6 clipped buds per foot of row. However, this threshold may be too low, particularly in the light of recent research showing that many varieties are able to compensate for clipper damage. The current threshold suggested by Cornell researchers is an average of 5 clipped buds per foot of row. New fields should be scouted and treated if they exceed the threshold. Scout the field again seven to ten days after treatment. You can stop scouting after all the flower buds are open.

Tarnished Plant Bug (TPB)

Both adults and nymphs feed on developing flowers and fruits causing 'cat faced' or 'button berries'. Watch for TPB from early bloom until harvest. Tap flower clusters over a white surface and look for the green nymphs as they come tumbling out. The suggested action threshold is 0.25 nymph per blossom cluster, or 1 out of 4 blossom clusters infested with one or more nymphs.

Thrips

Thrips are small insects that feed on flower parts. They can cause bronzing of the fruit when present in high numbers. Thrip infested fruit are usually very small and hardy. Thrips have been suggested to be a possible cause of the "seedy berry" syndrome observed in the Midwest in past seasons. It is believed that thrips do not overwinter in the Midwest.

Mites

Mites are tiny soft-bodied insect-like creatures that feed on strawberry leaves. They suck juice from the plant resulting in bronzed or stippled appearance of the leaves. Yield reductions may result from high mite populations. The twospotted mite is a major problem mite species in Minnesota. Cyclamen mites have also been observed in the past. Some cultural practices and natural predators often provide adequate control of mite. Consult with your extension office for information thresholds and control options.

Spittlebugs

Spittlebugs are no more than an annoyance. Resist treating for this pest since it will not reduce your yield or your net income.

For more information consult the MDA’s: Field Guide for Identification of Pest Insects, Diseases, and Beneficial Organisms in Minnesota Strawberry Fields

Available at: www.mda.state.mn.us/ipm/strawberryfg

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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 May 21, 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.