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Corn
Volume 58 Number 12 Date 07/24/2014 WESTERN BEAN CUTWORM - Most pheromone and black light traps produced few moths this week, with the exception of an anomalous and very high count of 275 moths near Sparta in Monroe County. All other counts were below 16 moths per tap. Peak flight, or 50% adult emergence, should occur over the southern half of the state in the next two weeks. Oviposition on corn and dry beans has been under way since early July and is increasing as the flight accelerates. Treatment may be required for field corn with infestations affecting 8% of the plants at 90-95% tassel emergence. For processing sweet corn, the economic threshold is 4% of plant infested. Cumulative pheromone trap counts as of July 23 are summarized in the map below. EUROPEAN CORN BORER - The second flight began during the July 17-23 monitoring period, with captures of 6-14 moths reported from the Coon Valley, Mazomanie and Ripon black light trap sites. The appearance of summer moths signals that eggs are being deposited on corn, peppers, potatoes, snap beans and other vegetable hosts. If seasonal temperatures continue, black light traps could register peak emergence during the second week of August in portions of the southern and central districts. The treatment window for second generation larvae extends from 1,550-2,100 degree days (modified base 50°F). CORN EARWORM - Pheromone traps in Dane, Dodge, Fond du Lac, Green Lake and Jefferson counties registered low counts of 2-15 moths again this week. Black light traps in Monroe and Vernon counties also captured a few migrants. The economic threshold for this pest is 5-10 moths in three consecutive nights for corn and seven moths per trap per week for tomatoes. Counts from July 17-23 were as follows: Coon Valley 0, Cottage Grove 2, Green Lake 8, Janesville 0, Marshfield 0, Mazomanie 0, Oak Grove 15, Ripon 10, Sun Prairie 0, Watertown 3, and Wausau 0. -- Krista Hamilton, DATCP Entomologist 
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