Agronomic Crop Insects – June 22, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Soybeans
Early in the season there were a few reports of millipedes feeding on field corn and this week we have received reports of millipedes feeding on soybeans. In some cases, these same fields were also affected earlier by slugs. Similar to slugs, millipedes can feed on the cotyledons and stems prior to emergence resulting in death of seedlings. Unfortunately, there is little information available on the efficacy of chemical controls. Please refer to the following link for pictures and comments on what has been observed in other areas of the country. http://cropwatch.unl.edu/web/cropwatch/archive?articleID=4837611

With the recent hot weather, be sure to watch for an increase in both grasshopper and spider mite activity. Early control is needed with both of these pests. Some consultants are also seeing an increase in leafhopper populations in seedling stage soybeans. As a general guideline, a control may be needed for leafhoppers if you see plant damage and you find 4 leafhoppers per sweep in stressed fields and 8 per sweep in non-stressed fields.