New research suggests that neonicotinoids, a leading culprit in the ongoing decimation of honeybee populations, may also be snuffing out the next generation of bees by cutting the quantity and viability of sperm in male bees by nearly 40 percent, writes The Guardian.
“Our results demonstrate for the first time that neonicotinoid insecticides can negatively affect male insect reproductive capacity, and provide a possible mechanistic explanation for managed honeybee queen failure and wild insect pollinator decline” says the study, led by Swiss scientist Lars Straub and published in the journal Proceedings of the Royal Society B.
Straub’s team fed pollen paste laced with two neonics—thiamethoxam and clothianidin—to some bees and fed straight pollen paste to a control group. They found that the bees that were not exposed to the pesticide lived a full week longer than the pesticide-exposed bees, who lived a maximum of 15 days (though on average drones reach sexual maturity at 14 days).
“This study is important, as failures in honeybee queen mating is reported to be a growing problem for beekeepers,” said Dr. Christopher Connolly, a pesticide toxicology specialist at the University of Dundee’s School of Medicine who was not involved in the study.
Although Connolly told The Guardian that the study supported a “precautionary” approach toward neonicotinoids, he said the scientists who conducted the study should have investigated the two types of pesticide separately because it is unclear whether both “are commonly consumed together at these levels.”
High rates of population loss in honeybee colonies has been a vexing problem for more than a decade. Beekeepers across the United States lost 44 percent of their honeybee colonies in the past year, nearly as bad as losses sustained in 2012-13.The leading causes are thought to be parasites such as the Varroa mite, disease, poor nutrition and pesticides. Researchers say the Varroa mite is a clear culprit. Environmentalists want to restrict use of neonicotinoids, a popular pesticide among farmers and gardeners.