Assessing sublethal stress in honeybees exposed to “bee-friendly” neonicotinoid and pyrethroid pesticides


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


P23-1  Sat Jan 2  Assessing sublethal stress in honeybees exposed to “bee-friendly” neonicotinoid and pyrethroid pesticides Nenstiel, R*; Donahoe, C; Hranitz, JM; Surmacz, C; Bloomsburg University; Bloomsburg University; Bloomsburg University; Bloomsburg University csurmacz@bloomu.edu

Honey bees (Apis mellifera) contribute to worldwide agricultural pollination. Since 2006, bee pollinators have experienced global declines, which may be linked to widespread agricultural use of neonicotinoid pesticides and a phenomenon known as colony collapse disorder (CCD). While CCD appears to be caused by many factors, neonicotinoid pesticides are indicated as a major factor in CCD. Neonicotinoids and pyrethroids differ in their chemical structure and strategies for application. We tested honey bees in acute exposure to two neonicotinoid (imidacloprid, acetamiprid) pesticides and one pyrethroid (deltamethrin) pesticide for sublethal motor coordination and stress responses. Motor and cellular stress responses (superoxide dismutase (SOD) activity) were measured after 4-h exposure to treatments. Control bees were fed 1.5 M sucrose and treatment groups were fed sublethal doses (1/5th LD50 to 1/500th LD50) of pesticides in 1.5 M sucrose. Doses were similar to those reported for the natural environment. After treatment, we evaluated the movement of the abdomen, legs, antennae, and proboscis extension reflex and calculated motor scores. Bees displayed impaired motor coordination at 1/5th-1/10th LD50 when fed imidacloprid and at 1/5th LD50 when fed with acetamiprid. Deltamethrin did not impact motor coordination at the doses used in our study. Bees displayed increased SOD activity at 1/5th-1/10th LD50 treatments of imidacloprid but no difference in SOD activity among acetamiprid or deltamethrin treatments. This suggests acetamiprid and deltamethrin are safer to honey bees than imidacloprid.

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