In this issue:

Feature Article: Cabbage Looper Takes Off!

Minnesota Vegetable IPM Field Day

Plant Disease Clinic Update

Potato Leafhopper Infestations on the Rise!

Potato Leafhopper Infestations on the Rise!

Bill Hutchison, Dept. of Entomology, Unviersity of Minnesota, St. Paul, MN, 55108

PLH nymph-left, adult-right (Photo courtesy of Marlin Rice, Iowa State University)

Potato leafhopper (PLH) adult counts have increased this past week in SW, Central and SE Minnesota, in snap beans and alfalfa (other crops such as potato should also be checked). Vegetable growers should also be reminded that PLH will move out of alfalfa, when cut, into nearby vegetable crops! Van Larson, crop consultant in SE MN, indicated this week that adult counts have been as high as 2-5X the economic threshold in alfalfa in the Rochester area (approx. equal to 2-5/sweep or more). Primary crops to watch in the coming weeks include: all green and lima beans, potatoes, and dry edible beans.

Control: PLH is one of the easiest insects to control with most labeled insecticides. Unfortunately, there is not much practical biological control available. Thresholds for snap beans are shown below.

Insecticides labeled for PLH control in snap beans include: Capture, Asana, Di-Syston, Orthene, Sevin, Lannate, Methoxychlor, Thiodan, Metasystox, and Dimethoate. Most snap beans forming pods at this time (e.g., in MN or WI) will not likely receive much egg-lay from European corn borer or corn earworm, until late July. However, one spray for PLH may be needed. For more information, including rates, etc., refer to the Midwest Vegetable Production Guide for 2001, also available at the Purdue web site at: http://www.entm.purdue.edu/Entomology/ext/targets/ID/index2001.htm

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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, c-tong@tc.umn.edu
Production Editor: Suzanne Wold, Department of Entomology, 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 July 12, 2001
The University, including the Minnesota Extension Service, is an equal opportunity educator and employer.©2001 Minnesota Extension Service, University of Minnesota. All rights reserved. Contact copyright@extension.umn.edu for information on reproduction or use of this material.