Wild honeybees have a new enemy: nicotine-like pesticides. Neonicotinoid pesticides do not kill them off in an instant. Rather, exposure to nicotine-like pesticides leads wild bees to produce more female workers. With limited male bees, the consequences would affect the species' long-term survival.
In past studies wherein the honeybees were artificially exposed to nicotine-like pesticides, the chemicals were revealed to alter the bees' ability to find food. While this finding also puts their survival at risk, the new study found that in the wild, honeybee colonies may appear to be undisturbed by the chemical exposure. However, researchers found that the wild honeybees counteract the chemical by producing more female workers. While wild bee colonies may appear full and unthreatened, their demographics show otherwise. With more females than males, long term survival is also put at risk.
"The most exposed colonies modified the timing of their reproductive investment, delaying drone brood production in favour of increased worker brood production," said lead study scientist Dr. Mickael Henry from the French National Institute for Agricultural Research (INRA).
In 2013, the use of three neonicotinoids in flowering plants was banned for two years by the European Union. The UK government highly opposed the neonicotinoids ban; however, they were obliged to employ the new rules.
University of Dundee's Dr. Christopher Connolly commented that the change in demographics carries serious implications in the species' reproduction. Connolly added that it is vital to remember that not all insect species have the same counteract capacity and could be more at risk when exposed to neonicotinoid pesticides. There are already various reports of the neonicotinoid pesticides' effect on honeybees in lab settings. University of Birmingham's Dr. Scott Hayward said that the research clearly identifies the direct effects of neonicotinoid exposure in wild honeybee mortality in the field.
Earlier in 2015, researchers from the Newcastle University found that bees could also get 'addicted' to sugar solutions laced with two pesticides: thiamethoxam and imidacloprid. In another study, researchers from the Lund University found the bumblebee colonies in areas treated with neonicotinoids stopped growing. Moreover, these colonies produced less queen bees. Both studies showed the detrimental effects of pesticides among bee species.
The findings were published in the Proceedings of the Royal Society B journal.
Photo: Bob Peterson | Flickr
