Evaluation of registered pesticides as repellents for reducing blackbird (Icteridae) damage to sunflower

Chemical feeding repellents applied to ripening sunflower might help reduce blackbird (Icteridae) damage, which is a chronic agricultural problem from seed formation to harvest. However, costs are high to develop and register new repellents for agricultural use. In 2003 and 2004, we evaluated feeding repellency of 8 pesticides registered by the Environmental Protection Agency for use in sunflower. Caged red-winged blackbirds (Agelaius phoeniceus) were fed unshelled sunflower seeds treated with the following pesticides: 5 pyrethroid insecticides, an organochlorine, an organophosphorus, and a fungicide. Compared to untreated reference groups, feeding rates were reduced for 4 of the 5 pyrethroid insecticides. Only the organophosphorus (chlorpyrifos), however, significantly decreased feeding rates. More research on repellency effects of this product in field efficacy trials is probably warranted based on the results of our cage experiments. Depending on timing of application, registered insecticides with blackbird feeding repellency could provide supplemental economic benefits to sunflower producers through dual purpose use.