According to a latest study focused on male honeybees, two insecticides prohibited in a few European countries but in use in the United States can notably decrease the ability of the drones to reproduce.

Published in Proceedings of the Royal Society B, the main biological research journal of the Royal Society, the study has discovered that the two chemicals thiamethoxam and clothianidin, belonging to the insecticides’ neonicotinoid family decrease the living sperm in male honeybees, known as drones, by roughly 40%.

The study’s lead author Lars Straub, a doctoral student at the University of Bern in Switzerland, said that they have managed to demonstrate for the first time ever that neonicotinoid pesticides can have an effect on the male reproductive system.

The pesticides’ impact on honeybee populations is just one of the several factors resulting into periodic declines.

Other studies have shown that neonicotinoids isn’t safe for the health of individual bees and female insects’ reproductive ability. The latest study has shed more light on the dangers of the pesticides for males, detecting that the bees exposed to the two chemicals had 39% lesser living sperm on average in comparison to bees that hadn’t been subjected to them.

The two neonicotinoids used in the research were prohibited in 2013 in the European Union, but are in use on an industrial scale in the United States. According to the Environmental Protection Agency, it is looking forward to release risk assessments for both the chemicals, and another neonicotinoid, dinotefuran, in December.

Scientists are worried about the fall in the bees’ population over a large part of the past ten years.

A notable amount of the worldwide food supply relies on plants that need pollinators like bees for survival. Any prevalent danger also makes way for a greater ecological threat.