As many regular readers know, our longtime IPM Specialist, John Obermeyer, retired last week after over 30 years of dedicated service.
As many regular readers know, our longtime IPM Specialist, John Obermeyer, retired last week after over 30 years of dedicated service.
This week, I was contacted about a 300+ acre, 5-6 leaf cornfield with multiple problems, described as plants dying and toppling over with feeding damage at the base of the roots.
Moth flights for both black cutworm and armyworm have been impressive this spring. Unworked/untreated fields are plentiful, and so is the plant life, meaning that there has been no shortage of egg-laying opportunities for these pests. Once soils dry, there will be no luxury of time to prevent a green-bridge, that is to starve the small larvae before they switch from feeding on the dying weeds/cover crops to the emerging crop. So, should one be tempted to be proactive and add some “cheap” insecticide in with the burn-down herbicides. A few factors to consider: First, seed-applied insecticides and many varieties of Bt-traited corn offer some suppression of black cutworm. The systemic activity of the seed-applied insecticide, and/or the protein production of the Bt-corn are optimal when the corn seedling is actively growing, not so much when corn is stressed. Their performance against larger larvae, >0.5”, is greatly reduced, meaning the[Read More…]
As folks get out to inspect corn ears, especially in northern counties where western bean cutworm is a greater concern, they will find “little black bugs,” especially where kernels are damaged. Their presence is in response to previous damage to kernels, which includes insect and/or bird feeding, hail, etc. In addition, hybrids with short ear husks seem to be more prone to exposing kernels, making easy access for rootworm and Japanese beetles to compromise ear tip kernels while feeding on silks. These small, opportunistic insects are feeding on decaying kernels and subsequent molds, NOT directly damaging the crop. They are simply fulfilling their niche in the cycle of life, “clean up in Aisle 3.”
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