Will it be a 'good' year for black cutworms and a 'bad' year for farmers? What about European corn borers, or soybean aphids? And what did the winter do to help or hinder insects?
These are all questions you would like to have answered this time of year, especially as you're deciding to apply a soil insecticide or not. With so much triple-stack corn with protection to corn borer and rootworms out there in Indiana and Illinois, it may not be as burning a question for some as it used to be. However, it's still good to have some idea of what's coming.
Here's a brief look.
Soybean aphids- Christian Krupke and an Illinois researcher made an amazing discovery last fall. After a late-season blitz by soybean aphids that took them into southern counties very late in the season. Double-cropped soybeans attracted aphids in late September to some places they may have never visited at that time of year before.
Yet when the entomologists visited the haunts where this more northern pest overwinter, they found fewer than normal number of aphids, not higher. And there was a cause- apparently the perfect storm that caused aphids to swarm in mid-September and wind up farther south than usual also encourage their natural predators. There were many dead aphids, but nearly as many live ones as the pair expected.
"A fungal epizootic swept through this impressive aphid buildup on buckthorn (host plant) and decimated the population," says Mike Gray, an entomologist at the University of Illinois. "Consequently, I expect a very small spring flight from buckthorn to soybean fields."
Corn borer- European corn borer numbers have dropped so low that Purdue University entomologists no longer carry out their statewide estimates of the borer population at the end of the season. The population apparently reached all-time lows across Iowa and Illinois last year, states where it's usually more prevalent than it is in Indiana. Gray says spring flights of this insect could be barely noticeable.
Western corn rootworm- Here's one you can't ignore. It causes challenges somewhere every year, especially now that a variant form can lay eggs in soybean fields. However, Gray says densities of rootworm were low in 2009. Still, be ready for this pest in 2010.
Japanese beetles- Expecting low populations of all pests would be asking too much, and it is. Japanese beetles, emerging from white grubs, have vexed producers recently and will continue to do so, Gray says. Winter snow cover during cold periods probably buffered effects of cold temperatures and helped white grubs survive, he concludes.