Issue No. 14/June 25, 2004
Japanese Beetle Update
Japanese beetles have arrived in Illinois, with levels increasing. The insects usually clump, so be sure to scout throughout a field to accurately determine the level of pest pressure. Insecticides labeled for control of Japanese beetles in corn are listed.
Corn Rootworm Larval Injury Reports Continue
In addition to continuing reports of corn rootworm larval injury, the first report of western corn rootworm adults has been received, from experimental plots in Urbana.
Miscellaneous Insect News
Brief notes are offered on European corn borer, corn earworm, potato leafhopper, and armyworm.
Does Cooler Weather Now Help or Hurt?
Lower daytime temperatures can have both negative and positive effects on corn development, but on balance a modest positive effect is predicted given the crop's advanced growth. In soybean, tracking the fate of early flowers can give a general indicator of the state of the plant. Vegetative growth staging in soybean is addressed. Wheat yields in Urbana, though lower than last year, were better than expected given the suboptimal weather during grain fill. Recent weather has not favored field pea yields.
Reports are provided this issue for northern, southern, and west-central Illinois.