By TIM ALEXANDER
URBANA, Ill. — The development and emergence of corn rootworm is following the same course as crop development in 2013 – late, thanks to above-average precipitation throughout much of Illinois in the spring.
This is according to Mike Gray, a professor and assistant dean for University of Illinois Department of Crop Sciences. He leads an annual survey tracking western corn rootworm emergence in research plots across Illinois.
“As we compare this year with last year, it’s been a cooler, wetter summer. It’s an environmental effect of things being a little bit slower this year in crop development,” Gray said last week, of the delay in corn rootworm emergence many farmers are reporting.
“It’s fair to say the overall (rootworm) feeding, emergence pattern and injury to roots is much later this year. It’s not uncommon as you get into August to have some residual root feeding, to still have some lingering adult emergence.”
Though Gray wasn’t ready to talk rootworm population density numbers yet, he hopes to begin releasing more definitive information from the survey on the U of I bulletin website at www.bulletin.
ipm.illinois.edu as early as this week.
“We just finished our digs, washings and root rating process. We haven’t really had a chance to look at the numbers, but my hope is that we will be able to get a preliminary release of some of the information for the four main rootworm studies on the website soon,” he said.
Gray said through his personal observations it appears there has been a quick return to near-normalcy in both crop development and the development of the pests that plague them this year, following the weather anomalies of 2012 and this spring.
“I would say that this year is probably a little more typical or behind compared to some other years. But when you compare this year and last, you are looking at bookends, at extremes,” he said.
A short video detailing how the U of I’s annual western corn rootworm evaluation surveys are conducted was posted by Gray to the bulletin website late last week, in advance of the release of the final survey results.