Japanese beetles are emerging in eastern Nebraska and will continue to emerge for the next couple of weeks. As numbers will be highest in field margins, growers are advised to scout across the whole field before determining the need for treatment.
By using a degree-day model, growers can account for the effect of temperature on insect development and approximate when certain insect stages will occur. See predicted cutworm flights and recommended scouting periods for 14 Nebraska locations.
The Handy Bt Trait Table, which lists the types of Bt hybrids present for all commercialized corn, has been updated for 2018. Now in its 15th year, the table has become the standard authoritative reference to Bt toxins in corn.
Spider mite populations are increasing in Nebraska. Fields should be scouted and the species correctly identified to provide proper management. Population levels should also be considered when treating fields with other insecticides that may knock out all natural predators, leading to population explosions of spider mites.
Western corn rootworm beetles began emerging in southeast and south central Nebraska this week. Before corn silks emerge, they're apt to feed by scraping the surface tissue, leaving a white parchment-like appearance.
University researchers are studying why suspected wheat stem sawflies are being found again this year in Nebraska corn, previously thought to be a non-host. Major yield loss is not expected in corn from this pest.