Are Mild Winters Creating More Insect Problems?

In 2012, agronomist Ed Corrigan got an early start to scouting crops for insect damage.

"Because of the record warmth in March and April, that really drove the insects to emerge earlier than normal," Corrigan said. "And of course the crop was planted, and the heat really tends to really activate their systems."

The drought also weakened defensive traits and supercharged the insects' diets.

"The juice, inside the corn plants, soybean plants, alfalfa, all plants, has less water in it, and more nutrition," Corrigan said. "And that stimulates an additional amount of growth and activity of those insects."

Spider mites and leaf-eating beetles went after the soybeans and root worms went after corn roots before they started what is referred to as silk clipping.

"Root worms hatch into a beetle and that tends to cut the silks and doesn't allow the corn to pollinate," Corrigan said. "Of course in dry weather, pollination is very key and very short lived."

According to Illinois State Museum Zoology Chairman Dr. Tim Cashatt, those insects may have survived in greater numbers due to the mild winter, conditions which may be repeating right now.

"We've not hit zero yet, here," Cashatt said. "And just intermittent, cold freezes isn't going to help deter insect populations at this point."

But the harshness of the winter isn't the only thing affecting the survival of the insects.

"It also depends on parasite populations, diseases, and predators," Cashatt said. "And all of these are also dependent on climate as well. It's a balance between all these, and it's very difficult to pin this to one particular factor."

The fact that the bugs had such a good year in 2012 may give them an additional head start in 2013.

"Number one is that there's a lot of them," Corrigan said. "The second thing is that the egg lay is potentially deeper. And in dry soil conditions, we've got cracks in the soils. They will move down and lay deeper, and that protects them from the winter freezes and a lot of the mortality of that insect over the winters."
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Reporting in Sangamon County, Mike Brooks, ABC NewsChannel 20.Are Mild Winters Creating More Insect Problems?