2018 ASHS Annual Conference

Neonicotinoid residue in greenhouse plants may alter bee behavior. Imidacloprid residues in pollen of Ruellia at 5 wks (267 ppb) decreased 50% by 10 wks (125 ppb); Calibrochoa at 5 wks (492 ppb) decreased 80% by 10 wks (96 ppb); and dinotefuran residue at 5 wks (748 ppb) decreased 88% by 10 wks (96 ppb). These levels may alter survival or behavior in bees. Pymetrozine (Endeavor) residue at 5 wks (126 ppb; 1/9) decreased 100 % by 10 wks and its use use will reduce insecticide exposure to bees. These data support the FOE Gardeners Beware reports that showed 62% of purchased plants can contain neonicotinoid residue (2 to 879 ppb).