Issue No. 10/May 28, 2004
ALERT:Field Observations on Soybean Aphids in Northern Illinois
On May 6 and 7, David Voegtlin, an entomologist with the Center for Ecological Entomology, Illinois Natural History Survey, and Bob O’Neil, an entomologist with the Department of Entomology, scoured the countryside in northeastern Indiana in search of soybean aphids on Rhamnus cathartica (common buckthorn) and Rhamnus alnifolia (native alderleaf buckthorn).
Armyworms Are Making Their Presence Known in Some Areas
Reports of armyworm feeding in Bond, Clinton, and Montgomery counties may indicate only a localized problem, but everyone should be on the alert. Economic thresholds in wheat and corn are discussed, and suggested insecticides and rates are listed.
Grape Colaspis Larvae May Be Causing Some Injury to Corn
We've heard of a few incidents of grape colaspis larvae (which may be mistaken for small white grub larvae) causing injury in cornfields. Identification and injury symptoms are described. There is no rescue treatment; with extensive enough damage, replanting may be a consideration.
Will European Corn Borer Reemerge as a Prominent Insect Pest in 2004?
Though European corn borer infestations have been anemic for 1999-2003, this year's early corn planting means that producers should scout fields for first-generation injury.
Monitoring for European Corn Borer
Anyone monitoring European corn borer or corn earworm traps is urged to submit reports of activity.
Slugs in No-Till, Part II
An earlier article on this topic (issue no. 8) was truncated by mistake. Conditions that favor pest development, injury symptoms, and control options are outlined.
Pokeweed Biology and Control in Corn and Soybean
The perennial common pokeweed has become more prevalent across Illinois. Identifying characteristics, management options, and postemergence herbicides for treatment are detailed.
Crop Growth Charges Ahead
Corn and soybean are both growing fast. In most years, early development of corn is an unqualified advantage. Where hail has hit corn, be sure to assess the growth stage right away. Where it has hit soybean, check to see what part of the plants was injured. Wheat appears considerably ahead of normal development.
Predicting and Measuring Nitrogen Loss
Techniques are detailed for assessing nitrogen potentially lost because of excess water, along with guidelines for deciding whether to apply additional nitrogen and how to do so.
Reports are provided this issue for northern, southern, and west-central Illinois.