By Matt Reese
Is spring here? Based on the vast number of bugs on this just cleaned bumper after a 15-
minute Central Ohio drive, the insect population seems to think so. The sunny skies are warming soils fast, though more rain in the forecast could slow the warming trend.
In general, Ohio can expect more of the same in the coming weeks, according to Jim Noel with the National Weather Service who contributes to the Ohio State University Extension CORN Newsletter.
“Nothing has changed since our last update,” Noel said. “The outlook for the rest of March is for an active pattern with above normal temperatures, above normal rainfall and some risk of severe weather. What will be quite different in 2012 versus 2011 is that the spring will not be as cool. It also will be wet, but not as wet as 2011 and the wetness will likely end earlier than 2011. The threat for severe storms, however, is elevated due to the warm temperatures and active pattern.
This spectacular March weather is following one of the warmest winters in recent years. One indication of that is the historically reliable “flea beetle index” used by OSU Extension entomologists to predict flea beetle populations and the resulting Stewart’s wilt potential. The index is based on the sum of the average temperatures (Fahrenheit) of December, January and February. Sums less than 90 indicate negligible disease threat. Sums from 90-95 indicate low to moderate levels, 95-100 indicate moderate to severe and values over 100 predict severe disease threat. In 2012, the entire state is over 100 with Wooster at 102.5, Ashtabula at 103.1, Hoytville at 100.2, South Charleston at 105.7, and Piketon at 103.1.
“We would recommend that growers scout for flea beetles, especially if they have planted a hybrid that is susceptible to Stewart’s disease. Normally we would recommend that growers wanting to take preventive action against flea beetles apply a commercially applied insecticide seed treatment labeled for flea beetles,” OSU entomologists wrote in a recent CORN Newsletter. “However, the realization is that most field corn planted these days, especially all transgenic hybrids, already comes with an insecticide seed treatment applied. Thus, it is mostly non-transgenic corn that might need to be treated specifically for this concern. Also, most field corn hybrids are more resistant to wilt than sweet corn. Dent corn hybrids vary greatly in their resistance to the leaf blight stage phase of the disease. All sweet corn varieties are susceptible to wilt in the first leaf stage.”
In addition, even with higher flea beetle populations, they may not necessarily be transmitting the disease. The bottom line, though, is that Ohio’s farmers better be ready for bugs in 2012. Bumpers don’t lie.