In this Issue:
VEGETABLE NEWS
Vegetable Insect Pest Update
NEWS YOU CAN USE
STRAWBERRY NEWS
APPLE NEWS
Apple Pest Focus: Dogwood Borer (Synanthedon scitula)
| Vol 4 No. 4 | June 1, 2007 |
Vegetable Insect Pest Update
Eric Burkness & Bill Hutchison, Dept. of Entomology, University of Minnesota, St. Paul
What a difference a week makes….pest pressure has remained relatively low but is increasing in cabbage in the Rosemount, MN (Dakota Co.) area. Transplanted cabbage (10-12 leaves/cupping) had a 10-20% infestation with diamond back moth larvae (DBM) and 20-30% of plants had a low level of shot holing. Late instar DBM larvae and DBM pupae were present indicating that there will soon be a new generation of adults laying eggs in the field. Imported cabbage worm and cabbage looper larvae have not been detected so far. However, cabbage looper adults are expected in late June to early July as they migrate from southern locations with the aid of southerly winds. Flea beetle damage was present but limited to the field edge on younger 6 leaf cabbage.
 PLH adult (courtesy of Ted Radcliffe, U of MN) |
Recent Low-pressure weather systems the past few days continue to aid the increasing potato leafhopper (PLH) populations. On 5/21, we detected our 1st PLH adult in alfalfa at Rosemount, and PLH was not present in early planted snap beans. However, on 5/30, PLH populations in alfalfa had climbed to 2 adults/sweep. Note: although this infestation has reached the traditional economic threshold for 12” alfalfa, most fields are now ready to cut (or were just recently cut). Fields in early bloom should be cut ready than treated with insecticide. After harvest, fields can then be checked again for PLH. In snap beans, PLH populations on 5/30 had increased to 0.5/sweep on 2nd trifoliate plants, which is at threshold. This demonstrates the value and need for regular scouting trips to the field and to space them not more than a week apart. This is especially true for insect pests that migrate into Minnesota, as populations can rapidly increase above threshold over a short time period; just as important, they can drop below threshold removing the need to apply an insecticide. Bean leaf beetle (BLB) populations have remained low this week in both alfalfa and snap beans. |
European corn borer (ECB) populations have finally been detected in our black light trap at Rosemount with 2 moths being captured/night since 5/25. Make sure to check the progress of the ECB flight across Minnesota on the VegEdge website at http://www.vegedge.umn.edu/2007/MNlist.htm. In addition to ECB, we also caught our first corn earworm (CEW) moths of 2007. As with PLH, CEW has also benefited from the recent weather events and strong southerly winds. Our first capture, in wire mesh pheromone traps, was on 5/25 and we caught 3 additional moths on 5/30. Although this trap catch is low, this information is useful for determining what type of weather events lead to significant CEW movement from the south and helps us determine when we are at major risk of CEW movement into Minnesota. The progress of CEW trap catch can also be viewed on the VegEdge website at http://www.vegedge.umn.edu/2007/CEW.htm.
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
The University, including the Minnesota Extension Service, is an equal
opportunity educator and employer. Privacy Policy
©1999-2007 Minnesota Extension Service,
University of Minnesota. All rights reserved. Contact
copyright@extension.umn.edu for information on reproduction or use of this material.