WHEN WISCONSIN CORN GROWERS switched to a safer insecticide recently, an unexpected problem descended out of the clear blue sky. Famished sandhill cranes, fresh from their spring migration, began arriving in farmers’ fields and gobbling up seed and young plants.
“They started having cranes come in and pull all the corn—maybe 30 percent of their stands. Some growers would have to replant an entire field,” says Eileen Cullen, a CALS associate professor of entomology.
Normally, cranes wouldn’t fall within the purview of an entomologist, but growers connected their woes to a change in their insect management practices. Previously, they had treated corn seed with lindane, a carcinogenic insecticide that cranes found unappetizing. When lindane was banned for corn use by the EPA in 2006, Cullen began receiving calls for help, and she decided to help “take corn off the menu”
At first, some growers asked Cullen to help bring back lindane, but Cullen, who specializes in integrated pest management to control insects, pursued another strategy. Working with the International Crane Foundation, the Wisconsin Corn Growers Association, a private company, and state and federal agencies, she led testing of several low-toxicity bird repellents derived from plants. After some lab work and field trials, she sought and gained approval for a biopesticide that can be safely applied to corn seeds.
Cullen says some farmers are hesitant about the added costs of the treatment and would prefer a crop-loss compensation program. But the seed coating provides at least one tool for farmers to keep their corn profits from going to the birds.