In this issue:

Corn Earworm Migration Continues

CEW - Frequently Asked Questions

How to Monitor for CEW

Cabbage Looper Still Active

Pesticide Residues and IPM

Email Access and Pest Info

Corn Earworm Migration Continues

Corn earworm (CEW) moth catch in southern MN continues to remain high at some locations. (See CEW Figure).

As indicated previously, CEW is not believed to have the ability to overwinter in MN/WI latitudes. It may overwinter as far north as southern Illinois. Infestations in MN therefore originate primarily from long-distance migrations from the southern cotton-belt or gulf-coast states. For example much of our late-season CEW (late-August) are believed to come from senescing field corn in Texas and northeastern Mexico. In 1994, I collaborated on a "weather-balloon" CEW migration study with Texas A&M researchers. After releasing balloons, simultaneously with the onset of a major CEW adult emergence in Texas, the meteorologists tracked the moths and balloons northward, eventually going over MN and into southern Ontario. Arrival of the balloons coincided with CEW trap catch in MN.

Again, my rationale for the added CEW pressure this year, was the unusually high number of southern storms coming into MN in May-July. These jet streams brought above avg. # of CEW (and potato leafhopper) than we typically get. Thus, we had EARLY CEW this year (June-July), on top of the high CEW #s that come in this time of year. As expected, the typical late-Aug flight usually only hits the latest planted or latest maturing sweet corn.

Co-Editors: Bill Hutchison, Department of Entomology, University of Minnesota
Jeanne Ciborowski, IPM Program, Minnesota Department of Agriculture
Production Editor: Rebecca Hines, Research Associate, University of Minnesota

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 November 11, 1999.
The University, including the Minnesota Extension Service, is an equal opportunity educator and employer.©1999 Minnesota Extension Service, University of Minnesota. All rights reserved. Contact copyright@extension.umn.edu for information on reproduction or use of this material.