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

Seedcorn Maggot: Despite the cool, wet weather we have been experiencing, degree-days for SCM continue to accumulate (currently at 841.9 degree-days, base 39° F ). We have seen a marked increase in our SCM trap catch (160/sticky card) at Rosemount, which coincides with the approaching peak of the 2 nd generation. Our first assessment of seed damage in snap beans indicated 35% of the seed/plants had been fed on by SCM. SCM ranged in size from very small (early instar) to large (late instar) larvae, suggesting that both 1 st and 2 nd generations are present.

Weekly average of SCM on sticky traps with or without lures, Rosemount, MN, 2005.
	Avg. number of SCM/trap
Date	Traps with lures	Traps without lures
5/2/05	4.2	1.0
5/9/05	53.4	6.2
5/16/05	47.4	9.4
5/23/05	160.2	45.8

Potato leafhopper (PLH): PLH is beginning to show up in our alfalfa sweeps. On May 24 we had 0.1 PLH/sweep. In contrast, on May 19 Bruce Potter in Lamberton, MN reported PLH as high as 0.9/sweep. This difference in densities demonstrates how quickly high populations can move into a region, and how variable populations can be from one location to another across the state. This emphasizes the importance of sampling on a regular basis, and how important that sampling information can be to making proper pest management decisions.

Bean leaf beetle (BLB): On May 24 we observed BLB (0.02/sweep) in sweeps taken in alfalfa at Rosemount. A nearby field of snap beans that was at the unifoliate stage had a light infestation of 0.07 BLB/plant. As the temperatures increase and snap bean plantings begin to emerge, we should expect higher infestation levels of BLB to develop.

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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, 651-297-3217, jeanne.ciborowski@state.mn.us , MDA, 90 W. Plato Blvd., St. Paul, MN 55107-2094. 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/biocon/fruitreports/

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