The makers of pesticides have long since known that certain types of pesticides are more harmful to bees than others. Contact pesticides, which are directly sprayed onto the plants can kill bees when they land on them, and dust or wettable powders are even worse because these types of pesticide stick to the bee and it brings it back to the hive.
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However, now researchers have realized an alarming trend where our little honey producers are concerned. In the past year, over one third of the bee population has simply disappeared. It seems that neonicotinoid pesticides, which are similar in nature to nicotine, have long been suspected of being a cause of Honey Bee Colony Collapse disorder. The disorder causes honey bee colonies to abruptly disappear and has been happening for almost a decade in North America. Neonicotinoid use became popular due to a low toxicity for mammals, but many countries have banned them from use due to the alarming reduction of honey-producing bees in the past.
Now the United States may jump onto the “banned-wagon” as well. A recent hearing by the House Agriculture Committee’s horticulture subcommittee met with experts in the field due to the alarming drop in honey-bee population. They discussed what could be done before the lack of bees hurts the worldwide production of honey, and many other crops which are typically pollinated by the bees as well.
Pollination is necessary for at least a third of global food production, including most fruits and quite a few vegetables as well. Many of the plants cannot reproduce without the help of pollinators, and managed honey bees are one of the most important pollinators of those crops.
Bee decline has hit many species hard, most especially bumble bees, as evidenced by a petition to list bumble bees as an endangered species. Until now, however, the theory that pesticides might be to blame remained unproven.
Recently, Harvard School of Public Health decided to research the possibility. Teaming up with the Worcester County Beekeepers Association in Massachusetts, they exposed 12 colonies to neonicotinoids, imidacloprids or clothianidins at “sub-lethal” levels. They also observed 6 untreated colonies in the same locations. All hives functioned as usual through summer and fall, but by the end of winter six of the twelve exposed hives had been abandoned. By contrast, only one untreated hive was lost, but this was due to a fungal infestation.