Sensitivity to imidacloprid insecticide varies among some social and solitary bee species of agricultural value

by Blair Sampson, Ale š Gregorc, Mohamed Alburaki, Christopher Werle, Shahid Karim, John Adamczyk, Patricia Knight Pollinator health risks from long-lasting neonicotinoid insecticides like imidacloprid has primarily focused on commercially managed, cavity-nesting bees in the generaApis,Bombus, andOsmia. We expand these assessments to include 12 species of native and non-native crop pollinators of differing levels of body size, sociality, and floral specialization. Bees were collected throughout 2016 and 2017 from flowering blueberry, squash, pumpkin, sunflower and okra in south Mississippi, USA. Within 30 –60 minutes of capture, bees were installed in bioassay cages made from transparent plastic cups and dark amber jars. Bees were fed via dental wicks saturated with 27% (1.25 M) sugar syrup containing a realistic range of sublethal concentrations of imidacloprid (0, 5, 20, or 100 ppb) that are ofte n found in nectar. Bees displayed no visible tremors or convulsions except for a small sweat bee,Halictus ligatus, and only at 100ppb syrup. Imidacloprid shortened the captive longevities of the solitary bees. Tolerant bee species lived ~10 to 12 days in the bioassays and included two social and one solitary species:Halictus ligatus,Apis mellifera andPtilothrix bombiformis (rose mallow bees), respectively. No other bee species tolerated imidacloprid as well as honey bees did, which exhibited no appreciable mortality and only modest paralysis across concentration. In contrast, n...
Source: PLoS One - Category: Biomedical Science Authors: Source Type: research