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Insecticides are a major tool for controlling pest species. Their widespread use results in damage to non-targeted insects, with honey bees particularly at risk. During foraging, honey bees learn and remember floral charac teristics that are associated with food. As insect pollinators, honey bees inadvertently contact chemicals which can have multiple negative impacts. The toxicity of two insecticides from different classes, ethion (47.79 mg a.i. L − 1 ) and hexaflumuron (500 mg a.i.L − 1 ), on learning, memory, and sensory perception were evaluated. We found that oral exposure to ethion had adverse effects on learned proboscis extension toward reward-associated odors and colors. In addition, we showed reduced sucrose consumption and sucrose responsiveness after expo sure. Hexaflumuron also impaired olfactory learning and memory and decreased responsiveness to sucrose and water. Exposure to sub-lethal concentration of the cholinergic organophosphate insecticide, ethion (47.79 mg a.i. L − 1 ), and the field-recommended concentration of hexaflumuron (500 mg a.i.L − 1 ), significantly impaired behavior involved in foraging. Our results suggest that several behavioral characteristics of honey bees be evaluated when testing an insecticide rather than relying on just one behavioral measure.
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Honey bee (Apis mellifera ligustica) acetylcholinesterase enzyme activity and aversive conditioning following aluminum trichloride exposure
Abstract Background Aluminum is the third most prevalent element in the earth’s crust. In most conditions, it is tightly bound to form inaccessible compounds, however in low soil pH, the ionized form of aluminum can be taken up by plant roots and distributed throughout the plant tissue. Following this uptake, nectar and pollen concentrations in low soil pH regions can reach nearly 300 mg/kg. Inhibition of acetylcholinesterase (AChE) has been demonstrated following aluminum exposure in mammal and aquatic invertebrate species. In honey bees, behaviors consistent with AChE inhibition have been previously recorded; however, the physiological mechanism has not been tested, nor has aversive conditioning. Results This article presents results of ingested aqueous aluminum chloride exposure on AChE as well as acute exposure effects on aversive conditioning in an Apis mellifera ligustica hive. Contrary to previous findings, AChE activity significantly increased as compared to controls following exposure to 300 mg/L Al 3+ . In aversive conditioning studies, using an automated shuttlebox, there were time and dose-dependent effects on learning and reduced movement following 75 and 300 mg/L exposures. Conclusions These findings, in comparison to previous studies, suggest that aluminum toxicity in honey bees may depend on exposure period, subspecies, and study metrics. Further studies are encouraged at the moderate-high exposure concentrations as there may be multiple variables that affect toxicity which should be teased apart further.
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- PAR ID:
- 10340092
- Date Published:
- Journal Name:
- BMC Zoology
- Volume:
- 7
- Issue:
- 1
- ISSN:
- 2056-3132
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1186/s40850-021-00103-8
