What bugs will bug you this year?
Though it's not easy to estimate this early in the year which insect pests will pressure crops the most this year, a few signs and trends point to which pests could cause farmers the most trouble later on in the growing season.
Field and weather conditions over the last few months make it likely that some common pests of recent years in the Corn Belt -- namely soybean aphids and corn rootworms -- aren't expected to cause as much trouble for the 2010 crop. For others, it's still too early to tell, says University of Illinois (UIUC) Extension Integrated Pest Management specialist Mike Gray.
"Accurately predicting what insects may do before corn and soybeans have been planted is always tough," Gray says. "For many insects that migrate into Illinois (e.g., black cutworms, corn leaf aphids, potato leafhoppers, fall armyworms, corn earworms), it's too early to assess the potential impact on production this season."
For other common pests, however, Mother Nature's already foreshadowing how much pressure they could exert this year.
- Soybean aphids
"Many of us remember the swarms of soybean aphids across central and southern Illinois late in the growing season last year," Gray says. "They were abandoning soybean fields and seeking out their overwintering host-buckthorn plants."
It was these huge migrating numbers that ended up being what could be the bug's undoing for this year's crop, he adds. "Perhaps not surprisingly, a fungal epizootic swept through this impressive aphid buildup on buckthorn and decimated the population," Gray adds. "Consequently, I anticipate a very small spring flight from buckthorn to soybean fields."
- European corn borer
"Last year, we reached all-time population lows for the European corn borer across Illinois," Gray says. "Densities were slightly larger in some areas of western Illinois. With such low overwintering numbers, the spring flight of European corn borers should be hardly noticeable in 2010 throughout Illinois.
- Western corn rootworms
Numbers were low for this pest in 2009. Gray says it could be attributed to 1 of 2 factors: The "large-scale increase in Bt usage" could be trimming populations, or last year's overall wet growing season could have played a larger role.
"Because Bt hybrids targeted at corn rootworms are considered low-to-moderate dose in their effects on corn rootworms, I suspect that environmental conditions last season contributed to the collapse of the corn rootworm population. Specifically, the very wet soil conditions throughout the spring resulted in high mortality of larvae soon after hatch occurred," Gray says. "Consequently, I believe many Illinois producers in 2010 should experience very light to moderate infestations of western corn rootworms."
- Japanese beetles
On the other hand, this bug could thrive in greater numbers this year, mainly because of the weather this winter, Gray says. "In spite of the very cold winter, the snow cover across many areas of Illinois should serve as a buffer and enhance the survival of overwintering grubs," he says.