Commercial Honey bees used to pollenate crops are exhibit to a wide multifariousness of agrarian chemical , including vulgar fungicides , which deflower the bee ’ power to oppose off potentially lethal parasites , grant to a new field of study by researchers at the University of Maryland and the USDA .
The study , published July 24 , 2013 , in the online journalPLOS ONE , is the first analysis of literal - world conditions encountered by Honey bees as their urticaria pollinate a chain of harvest , from apples to watermelons .
The researcher compile pollen from Honey - bee hives in plain from Delaware to Maine and analyzed the sample to find out which flowering plant were the bee ’ main pollen sources and what farming chemicals were commingled with the pollen . The researchers fed the pesticide - laden pollen samples to healthy bee , which were then test for their power to refuse infection from Nosema ceranae , a parasite of adult Honey bees that has been linked to the deadly phenomenon known as colony collapse disorderliness , in which intact Honey bee colonies suddenly die .
On mediocre , the pollen sample turn back nine different agricultural chemicals , including antifungal , insecticides , herbicides and miticides . Sublethal levels of multiple agricultural chemicals were present in every sample distribution , with one sample containing 21 different pesticides . Pesticides found most oft in the bees ’ pollen were the fungicide chlorothalonil , used on apple and other craw , and the insecticide fluvalinate , used by apiarist to ensure Varroa mites , common Honey bee pests .
In the field of study ’s most surprising find , bees that were fed the collected pollen sample containing chlorothonatil were nearly three fourth dimension more probable to be infected by Nosema than bees that were not exposed to these chemical , says Jeff Pettis , inquiry leader of the USDA ’s Bee Research Laboratory and the study ’s tether author . The miticides used to command Varroa speck also harmed the bees ’ ability to withstand parasitic transmission .
Beekeepers cognise they ’re making a swop - off when they habituate miticides , says University of Maryland researcher Dennis vanEngelsdorp , the discipline ’s senior author . The chemical compromise bees ’ immune system , but the legal injury is less than it would be if mites were left unchecked . But the bailiwick ’s finding that common fungicides can be harmful at real earthly concern dosages is new and points to a gap in existing regulations , he says .
“ We do n’t remember of antimycotic agent as having a disconfirming burden on bee because they ’re not designed to drink down insects , ” vanEngelsdorp say . Union regulations curtail the use of insecticides while pollinating insects are foraging , he says , but there are no such restriction on fungicides . “ You ’ll often see fungicide lotion going on while bees are forage on the crop . This determination paint a picture that we have to reconsider that policy . ”
In an unexpected finding , most of the crop the bees were pollinate appeared to cater their beehive with little nourishment . Honey bees get together pollen to take to their beehive and feed their new , but when the researchers gather pollen from bees foraging on aboriginal North American crops , such as blueberry bush and Citrullus vulgaris , they found the pollen came from other efflorescence plants in the area — not from the crop . This is probably because Honey bees , which evolved in the Old World , are not effective at collect pollen from New World crops , even though they have the ability to do so .
The study ’s findings are not directly colligate to CCD ; however , the research worker say the results shed light on the many factors that are interact to strain honey bee population .
