Study: insecticide appears to reduce live bee sperm by 40 percent

August 1, 2016

Swiss researchers from the University of Bern revealed a new fact: the common insecticides are dangerous for the sperm of bees, the are reducing it by 40 percent. The study is available from July 27 in the journal Proceedings of the Royal Society B.

One of the reasons of decreasing the population of male drones are insecticides, concludes the Swiss researchers. According to a controlled experiment, the insecticides from neonicotinoid-class just poisoning a pollen, which reducing the producing of live sperm by the drones 39 percent less. Insecticide doesn’t kill the drones literally but it’s dangerous to the species.

Drones’ job is to mate with the queen and die aftermath, reminds Lars Straub, the doctoral student at the University of Bern. Drones don’t gather nectar or pollen and are not able to sting; they die after mating.

But insecticide-treated pollen is a food for drones, that is a very dangerous factor. Poisoned drone isn’t able to produce needed amount of living sperm. According to data, the no-pesticide bee produced on average 1.98 million living sperm, the one with neonicotinoids in its food about 1.2 million.

A microscopic image of sperm of a honey bee drone. The blue sperm is alive. Insecticide neonicotinoid reduces the amount of live sperm in drone honey bees by 39 percent. Honey bee drones’ main job is to inseminate the queen and then they die.
A microscopic image of sperm of a honey bee drone. The blue sperm is alive, red is dead because of using the insecticide neonicotinoid.

Researchers from University of Bern could have “profound consequences for the health of the queen, as well as the entire colony.”