Volume 57 Number 11 Date 06/21/2012
SOYBEAN APHID - Populations are very low at most locations. Of the 39 fields examined in the southern, east-central and northwest areas from June 14-20, only 28% were found to have infestations. All had fewer than 2 aphids per plant based upon examination of 40 plants per field. Regular sampling should begin in the next two weeks as soybean fields enter the early reproductive stages of growth.
VARIEGATED CUTWORM - As previously noted, these caterpillars are particularly numerous this year and the larvae have caused extensive damage to a few soybean fields in the central and southern areas. Severe defoliation was documented on June 15 in a Fond du Lac County field after extraordinary numbers of larvae migrated from nearby alfalfa. Cutworms have also been reported or observed in soybeans in Columbia, Dodge, Green Lake and Manitowoc counties. The grower in Fond du Lac County is monitoring the field to determine if the plants will recover.
--Krista Hamilton, DATCP Entomologist