In this Issue:
VEGETABLE NEWS
Vegetable Insect Pest Update
STRAWBERRY NEWS
Renovation: An Important IPM Tool
APPLE NEWS
| Vol 3 No. 8 | July 14, 2006 |
Vegetable Insect Pest Update
Eric Burkness, Department of Entomology, University of Minnesota, St. Paul
Pest pressure in cabbage continues to remain low in the Rosemount area with light infestations of diamondback moth present in commercial fields. Despite this lack of pest pressure scouting activity should remain high as the cabbage looper should be laying eggs now.
Potato leafhopper (PLH) populations in alfalfa have dropped slightly from the last week of June to the first week of July, going from 0.8/sweep to 0.5/sweep. The presence of nymphs has finally been detected and this may explain some of the population decrease as adults of the 1st generation that migrated into Minnesota begin to die. However, populations of PLH have begun to move into snap bean fields as cutting of the 2nd crop of alfalfa is under way in most areas. Snap beans in the Rosemount area at the flower bud stage have populations of approximately 0.75/sweep, just under the threshold of 1 PLH adult/sweep. In addition, low levels of nymphs are present and indicate that the snap beans are at higher risk for damage because the nymphs will not leave the plants for the next several weeks.
Corn earworm (CEW) trap catch in most areas of the state has remained low. We would expect the main flight of CEW to occur later in August. European corn borer (ECB) trap catch has remained low in most areas with a small peak occurring in the last week. Currently, degree days for ECB are at 1218 through July 10th indicating that the 2nd generation of ECB has not started yet. The 2nd generation ECB should begin flying at approximately 1400 degree days, which should occur in the next week. The continued catch of ECB may be a reflection of the expanding range of the univoltine strain of ECB in the state (see graph). The univoltine flight typically peaks between the peak of the 1st and 2nd flight of the bivoltine strain of ECB (see the June 2nd article, http://www.vegedge.umn.edu/MNFruit&VegNews/Vol3/vol3n4.htm).
On July 10th, we captured our 1st western bean cutworm (WBC) in our blacklight trap in Rosemount, MN. While most damage and concern about WBC has been in southwestern Minnesota on field corn, the potential always exists for WBC outbreaks in sweet corn. We will provide updates as the season progresses.
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 Jean Ciborowski, 651-201-6217, jeanne.ciborowski@state.mn.us, MDA, 625 Robert St. North, St. Paul, MN 55155-2538. 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: http://www.mda.state.mn.us/ipm/ipmnews/
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.
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