Issue No. 3, Article 4/April 22, 2011
Neglecting Wireworm Scouting Could Be a Mistake
Ron Hines, an independent crop consultant in southern Illinois, has reported large infestations of wireworms in two separate fields in Massac County. Both fields were devoted to no-till corn production in 2010. Ron placed wireworm bait stations in both fields; after digging up the baits, he found an average of 35 wireworms per trap! The established threshold for wireworms is generally considered to be one per bait station. If this threshold is exceeded, producers are encouraged to consider applying a soil insecticide at planting, preferably one labeled for in-furrow placement. Rescue treatments are not an option.
Wireworm bait station, Massac County, Illinois. (Photo courtesy Ron Hines.)
Wireworms collected from bait stations, Massac County, Illinois. (Photo courtesy Ron Hines.)
Significant stand reductions in heavily infested fields often necessitate replanting the areas most affected. Use of a soil insecticide is encouraged during replanting. Although insecticidal seed treatments confer some protection against wireworms, intense infestations may overwhelm seedlings' ability to withstand feeding injury. Prolonged wet soil conditions and cool temperatures tend to enhance the prospects for increased wireworm damage to cornfields. Wireworms will continue to feed in the seed zone as long as soil temperatures remain cool. Click the following link for more information about the life cycle, biology, and establishment of bait stations for wireworms.--Mike Gray