MN Fruit & Vegetable IPM News - Vol. 4, No. 2

Insect activity has been relatively low thus far in 2007. We still have not detected any major insect pest species in cabbage, sweet corn, alfalfa, or snap beans in Rosemount, MN (Dakota Co.). Most crops are either just emerging, being planted or blowing in the wind. As in previous years, we are seeing early springtail activity at Rosemount. However, this year we are seeing the highest numbers in alfalfa. If you’ve had problems in the past with springtails, you may want to watch your emerging cabbage and cucurbit seedlings this spring (see pictures). For more information you can refer to last spring’s insect pest update, and the VegEdge factsheet on springtails. Besides the presence of springtails in alfalfa, we have also detected low populations of tarnished plant bug and aster leafhopper adults.

Bean leaf beetle (BLB) activity has remained low this week at Rosemount and we are still collating information for a followup on last week’s article regarding the possible use of an overwintering model to predict spring BLB populations. So look for information on this topic in next week’s newsletter.

The European corn borer (ECB) flight should be starting this week. Degree-days for ECB are at 380 as of Wednesday (5/16/07; base temperature 50°F). First moth catch should occur at approximately 375 degree days. However, with the rapidly changing temperatures we have been experiencing, keep in mind that ECB moths fly at night and the night-time temperature needs to be at least 55°F or higher for moths to fly. Therefore, even though the degree day requirements have been met for moth emergence, trap catches will not occur until we have warmer night time temperatures. In addition, if the cooler temperatures last for an extended period of time, the ECB moths will not be able to locate each other for mating, may have limited access to food, resulting in delays in egg-lay, all of which are detrimental to ECB populations. We will have much more information on ECB as the season progresses.

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ACKNOWLEDGEMENTS

Co-Editors: Bill Hutchison (hutch002@umn.edu), Department of Entomology, University of Minnesota, Jeanne Ciborowski, Minnesota Department of Agriculture, Ag. Resources Management and Development Division, and Suzanne Wold-Burkness (woldx018@umn.edu), Department of Entomology, University of Minnesota

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., Wednesday to Jeanne Ciborowski, 651-201-6217, jeanne.ciborowski@state.mn.us , MDA, 625 Robert St. North, St. Paul, MN 55155. 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/plants/pestmanagement/ipm/ipmnews.htm

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

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 manufacturer directions.

Last Revised May, 2007 by woldx018@umn.edu
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