A new scientific study adds to the growing amount of evidence that shows pesticides are harming bees. The study published this month in Proceedings of the Royal Society B is the first to look at how neonicotinoid insecticides impact male honeybee fertility – and the findings aren’t good.
Led by Lars Straub of the University of Bern in Switzerland, the researchers took bees that had been exposed to two types of neonicotinoid insecticides, thiamethoxam and clothianidin, and then monitored them in the lab. They found the exposed bees had shorter lifespans and their “living sperm quantity” was reduced by 39 percent, compared with bees not exposed to the insecticides. They said their findings showed “for the first time” that neonicotinoid insecticides can indeed “negatively affect male insect reproductive capacity.”
Drones hit sexual maturity around 14 days, but the research revealed 32 percent of the exposed bees had already died by that time. Only 17 percent of unexposed bees died by that time. Further, exposed bees only live for about 15 days, as opposed to unexposed bees who live for 22 days. These numbers don’t bode well for bees, according to researchers. They said, “This could have severe consequences for colony fitness, as well as reduce genetic variation within honeybee populations.”
The Guardian spoke with Peter Campbell of Syngenta, makers of thiamethoxam, about the study. Here’s what he had to say: “Given the multiple mating of honeybee queens it is unclear what the consequences of a reduction in sperm quality would actually have on queen fecundity.”
Scientific research has shown neonicotinoids reduce queen bee production and colony growth, and that neonicotinoids compromise physiology and reproductive anatomy in queen bees. The European Union banned neonicotinoids in 2013, although in 2015 the UK briefly lifted the ban.
Via The Guardian