Therefore, to test the effects of imidacloprid on sucrose responsiveness (SR), bees from three colonies were individually captured and fed with a sucrose solution containing a minute concentration of imidacloprid. After allowing the imidacloprid to be fully ingested in the gut, the bees were then harnessed and restrained in stainless steel tubes and presented with different sugar concentrations ranging from 0-50%. A response was recorded when the bee fully extended its mouthparts to accept and taste the solution.
To test the effects of imidacloprid of the foraging behavior of worker bees and their subsequent communication to nest mates, bees were first exposed to feeders of different sugar concentrations a short distance away from colony to represent a highly desirable food source no matter what the concentration. Specimens were individually captured and fed sucrose solutions of imidacloprid, marked and then re-released. Sucrose solutions with concentrations ranging from 0-50% were provided and the number of dances the forager bees performed after they visited these food sources was recorded.
Through extensive and careful experimentation, Dr. Nieh and his colleagues discovered that exposure to the chemical imidacloprid increased the sucrose concentration expected by honeybees from their food source. Because the honeybees expected high sucrose concentrations due to their exposure to imidacloprid, there was a decreased efficiency in foraging behavior causing the honeybees to accept fewer available food sources.
Flight and foraging activity of honeybees exposed to imidacloprid were unchanged, but the amount of waggle dances was notably decreased. Overall, honeybees that were exposed to imidacloprid became picky and uncommunicative to the detriment of the health of the colony.
Honeybees and the Future
Dr. Nieh’s work has shed light on the neural control of honeybee behavior and ecology and has huge ramifications for the future.
“The health of honeybees is important to our economy and agriculture. In California alone, a healthy almond crop brings in 2 billion dollars a year. The most valuable effect of beekeeping is pollination and the decline of communication due to the negative effects of pesticides has a multi-billion dollar impact on agricultural pollination,” said Dr. Nieh.
Dr. Nieh’s insightful research brings hope for the development of a chemical alternative that will help stave off honeybee death and encourage healthy colonies for the future of agriculture.
WRITTEN BY AREANA PARK. Areana Park is a Biochemistry and Cell Biology major from Eleanor Roosevelt College. She will graduate in 2015