|
|
|
Corn
Volume 59 Number 4 Date 05/22/2014 EUROPEAN CORN BORER - Emergence of the first spring moths may start next week in advanced southern locations. Most overwintered larvae are in the pupal stage, which requires 10 days to complete at average daily temperatures of 65°F. Degree day accumulations near Beloit and Platteville, currently the warmest locations in the state, are expected to surpass the 374 units (modified base 50°F) required for moth emergence by May 25. Forecasted nightly temperatures above 60°F for much of southern and central WI early next week should be appropriate for moth activity. BLACK CUTWORM - Significant flights were again registered at monitoring sites in the southwestern counties. Another 162 migrants arrived from May 15-21, for a cumulative total of 813 moths in 34 traps since mid-April. The comparatively large number of moths collected during the migration suggests that certain fields are at high risk of black cutworm damage this season. Included in this category are poorly drained and low-lying fields, those next to areas of natural vegetation, and fields that are weedy or with reduced tillage. The start of the primary damage period has been predicted for May 29 in Rock and Grant counties, May 31 in Dane County and June 2 in Portage County, and June 6 in Brown County. Crop consultants and growers are advised to begin inspecting corn (including Bt hybrids) for evidence of this pest next week. Pinholes in the leaves are an early indicator of potential cutting. -- Krista Hamilton, DATCP Entomologist 
|
|