Potential neonicotinoid impact on honey bees (Apis mellifera) in cantaloupe production
Potential neonicotinoid impact on honey bees (Apis mellifera) in cantaloupe production
Kira Nixon, Dr. Rick Foster
Purdue University
Honey bees (Apis mellifera) provide pollination services to many agricultural crops, including cucurbits. The presence of neonicotinoid residues in the pollen of flowers threatens honey bee health. Neonicotinoid insecticides are generally safer, more selective, and often more effective for managing pests than other classes of insecticides. Many neonicotinoids are, however, highly toxic to honey bees. Neonicotinoid use may be one contributing factor to the alarming decline of honey bee populations occurring in North America. The goals of this study were to first determine the potential neonicotinoid impact on honey bees in muskmelon production and to secondly determine the extent and duration of striped cucumber beetle control among treatments. Quantifying the potential neonicotinoid impact on honey bees was accomplished with two major objectives. First, I determined the residue concentrations of several recommended neonicotinoids applied at high and low label rates in muskmelon pollen. The delivery methods for the neonicotinoids included bedding tray applications, transplant soil drenches, foliar sprays, and seed treatments. Secondly, I coupled the field residue concentrations with known honey bee toxicological sensitivity to determine the health risk associated with such neonicotinoids and delivery methods. The neonicotinoids evaluated were imidacloprid, thiamethoxam, and acetamiprid and their corresponding metabolites imidacloprid olefin, 5-hydroxyimidacloprid, and clothianidin. The concentrations of thiamethoxam applied as a Platinum soil drench and Actara foliar spray as well as imidacloprid applied as an Admire Pro soil drench were present at levels that may cause adverse effects on honey bees. There are no known negative effects on honey bees at the concentration levels determined from the application of the thiamethoxam FarMore seed treatment and acetamiprid Assail foliar spray. The results have enabled us to modify our neonicotinoid product and application method recommendations to growers to maximize insecticide efficacy while minimizing honey bee health risks.
Keywords: honey bee, pollen, neonicotinoids, cantaloupe
