Forecasting insect pressures for this next growing season is as changeable as the weather. In fact, that's exactly what changes pest predictions the most — hot or cold temperatures and either plenty of moisture or lack of it.

“We get surprised every year by something,” says Mike Catangui, South Dakota State University extension entomologist. “So, there's no better defense than scouting.”

We asked leading entomologists across the Midwest what they expect will be the most feared pests this year. Here's what they claim will most likely be bugging you.

ILLINOIS

“I suspect the variant western corn rootworm (WCR) will be the primary insect challenge facing producers in central and northern Illinois. The variant WCR has adapted to crop rotation. Consequently, we've seen a significant increase in soil insecticide use on rotated corn since the mid-1990s.”
Mike Gray, University of Illinois

INDIANA

“I'd put my money on western corn rootworm. Year in, year out, it's our biggest yield robber in corn.”
John Obermeyer, Purdue University

IOWA

“In 2004, I'd cast my vote for the soybean aphid, especially if we have a drier than average July and August. If we have above average rainfall in July and August, then I'd predict no serious insect problems.

“From the perspective of dollars initially invested in crop production, the corn rootworm complex commands respect as a serious pest. Tens of millions of dollars are spent annually on insecticides to protect corn from injury by the larvae.”
Marlin E. Rice, Iowa State University

KANSAS

“Rootworm and corn borer, especially southwestern corn borer, are the two biggest pests we normally have.

“For soybeans, the top two pests would be soybean aphids and, in the central part of the state, soybean stem borer. If we happen to have a cool summer there's more chance we'll see heavier populations of soybean aphids.”
Phil Sloderbeck, Kansas State University

MICHIGAN

“We'll be watching soybean aphids in 2004.

“For rootworm, this is probably the first time we've encountered the soybean variant in any great number. (Soybean variant is the variant of corn rootworm that lays eggs in soybean fields rather than corn fields.) I think the variant rootworm may increase. Last year was a good rootworm year across the whole state, but we hadn't seen this much economic damage before in the southern part of the state with the variant. So even if we don't have a big problem yet, it's certainly changing insecticide use in that area.”
Chris DiFonzo, Michigan State University

MINNESOTA

“Soybean aphid was the big problem in Minnesota in 2003 and will continue to be a production threat this year. The cold winter may further reduce the threat of bean leaf beetles after the warm winters of 1998-2001.

“Corn rootworm will be a significant problem in the southwest third of Minnesota even though some mortality of eggs probably occurred over the winter.”
Ken Ostlie, University of Minnesota

MISSOURI

“Consistently, our biggest problem in corn is wireworm/white grub complex. I expect to see it again this coming year. We're now even seeing white grub problems on winter wheat. I expect flea beetle to be a major problem next spring, too, if we don't get more cold weather. The months of December and January were very warm here.

“In Missouri we always look for black cutworm and we could certainly have a black cutworm outbreak, but it's just really unpredictable until we get moth counts.”
Wayne Bailey, University of Missouri

NEBRASKA

“The soybean aphid is the main concern in Nebraska soybeans since it's a new problem. It's been expanding its range the last couple of years. We're not sure how far west it's going to go but aphids were pretty abundant in northeast Nebraska in 2003.

“For corn, rootworm is the No. 1 problem statewide. The other insect that is hard to predict but we're having problems with is grasshoppers in central and western Nebraska. In some parts of the state grasshoppers may be more destructive than soybean aphids or rootworm.”
Robert Wright, University of Nebraska

NORTH DAKOTA

“Our No. 1 insect pest on soybeans is the soybean aphid. It's slowly spreading into western North Dakota. Fortunately, populations have been below damaging levels in most of the state. We'll be watching soybean aphid movements carefully.

“On corn we still have some European corn borer and wireworm problems.”
Janet Knodel, North Dakota State University

OHIO

“We'll focus our attention on the soybean aphid and continue to monitor for first-year western corn rootworm (WCR) problems. Although not yet confirmed as a major problem in Ohio, there is significant grower concern with first-year WCR.”
Ron Hammond and Bruce Eisely, Ohio State University

SOUTH DAKOTA

“For soybeans, we're worried about the soybean aphid. I'm guessing since the third year was the worst in Minnesota (in 2003), our third year, which is 2004, will be our worst for aphids. Aphids colonized all our soybean growing counties last year, so this will be the first year we have aphids on a widespread scale.

“If you grow corn on corn on corn, you need to worry about rootworms. Corn borers are a threat every single year, too. And western bean cutworms have become a regular pest of both conventional and certain Bt corn hybrids since 2000.”
Mike Catangui, South Dakota State University

WISCONSIN

“We expect soybean aphids to be a factor in 2004, although it isn't known whether this pest will reach outbreak levels of 2003. With a cold winter we expect less of a bean leaf beetle problem. Warm winters tend to increase spring populations.

“It's not as much a case of how big a problem corn rootworm will be in 2004 as how we'll provide information on choosing from among several rootworm control tactics — some old and some new.
Eileen Cullen, University of Wisconsin