Volume 64 Number 7 Date 06/13/2019
EUROPEAN CORN BORER - The spring flight of moths continued for the second week, with very low counts of 1-10 moths registered in black light traps near Arlington, East Troy, Janesville, Pardeeville, Ripon and Sparta. The European corn borer degree day model suggests that peak moth emergence is approaching near Beloit, Madison and La Crosse, and should occur by June 20.
BLACK CUTWORM - Conditions remain favorable for localized cutworm infestations. Crop advisors and growers should continue to inspect fields until corn plants have reached the five-leaf (V5) stage. Signs of cutworm activity have been encountered in a few fields surveyed this month, though economic infestations (>3% of plants damaged) have not been observed. The cumulative moth count for the period of April 4-June 1 was 1,258 moths in 44 traps, with a high of 80 moths near Dodgeville in Iowa County. Cooperators may remove their traps now that the DATCP BCW trapping program has ended 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 beginning at 1,400 degree days (sine base 41°F). Spot treatment may be in order for fields with infestations affecting 5% or more of plants.
-- Krista Hamilton, DATCP Entomologist