Volume 63 Number 6 Date 06/07/2018
EUROPEAN CORN BORER - The spring flight of moths continued for the second week, with very low counts of 1-5 moths registered in the black light traps near Beaver Dam, East Troy, Pardeeville and Sparta. The European corn borer degree day model suggests that peak moth emergence has occurred near Beloit, Madison and La Crosse, and should occur by June 10 near Stevens Point. Most corn is too short for larval development at this time, so egg deposition is likely occurring on peppers, potatoes, snap beans and various weed hosts.
BLACK CUTWORM - Conditions remain favorable for localized cutworm infestations. Crop advisors and growers should continue to inspect fields for another two weeks or until corn plants have reached the five-leaf (V5) stage. Signs of cutworm activity have been encountered in surprisingly few fields surveyed this spring, despite planting delays and large moth flights throughout May. The cumulative count for the period of April 12-June 6 was 2,171 moths in 47 traps, with a high of257 moths near Waupun in Dodge County. Cooperators may remove their traps now that the DATCP BCW trapping program has concluded for the season.
STALK BORER - Migration of larvae from grassy areas into corn has started and is expected to increase in the week ahead. Spot checking the 4-6 border rows for plants with holes in the leaves, wilted whorls and other early signs of damage is recommended starting at 1,400 degree days (sine base 41°F). Control measures may be in order for fields with infestations affecting 5% or more of plants.
-- Krista Hamilton, DATCP Entomologist