Unintended Consequences of Seed-Applied Insecticides

Benefits of neonicotinoidtreatedseed?• Labeled for a variety of early-season pests,mainly soil insects• Efficacy is highly variable, very fewindependent efficacy studies• Do we need seed treatment on all cornplanted in North America? What are the costsvs. benefits?• Remember IPM? Applications of seedtreatments are not based on any monitoring/thresholds etc.Where/when do bees and corn overlap?Mostmanagedpollinatorsin the USspend MaythroughOctober inMN, ND, SDSummary• Honey bees living near fields where treated seeds areplanted have multiple routes of exposure toneonicotinoid insecticides throughout spring andsummer• Exposure may be by contact (dust, soil), by ingestion(corn and other pollen), and is likely a combination• Talc from planter exhaust is highly toxic, mobile and anobvious target for mitigation• Sub-lethal effects, synergies with other pesticides maybe important in evaluating overall effectsNow:Next steps• Determine how to limit movement of dust off ofplanting equipment and away from planting area• Evaluate other non-target effectsLater:• Examine when/where seed treatments are necessaryin crop productionLimits non-target exposure, increases durability ofinsecticides (avoid resistance) and maximizesproducer return on investmentAcknowledgements:PeoplePlot prep/hive maintenance/pollen counts:• Krispn Given• Nick Seiter• Gladys Andino• Caitlin Race, Madeline Spigler, Nicole Parker• Larry Bledsoe• Pete IllingworthAcknowledgements:Funding NAPPC Grant to CK AFRI Managed Pollinator Grant to GHPhotos/videos• John Obermeyer6