The researchers who conducted the study found that other species of bees, like honeybees – which are known to pollinate important crops, like almond crops – were not very affected by the pesticides, compared to bumblebees which die in large numbers.
However, the strange thing that has the researchers puzzled is that some bees are actually attracted by the crops that have been sprayed with pesticides, even though it can be fatal for them.
According to recent reports, over the past years the population of bees that are crucial for pollinating the crops are in a continuous decline.
The reports suggest that one of the main causes that kills the bees is the pesticide used on crops. Another factor is colony collapse disorder, but that has been narrowing in the last couple of years, experts say.
The bees that are exposed to a type of insecticide called neonicotinoid are experiencing ill effects, including the massive reduction of wild bees population.
Another effect that pesticides have on wild bees is that it affects their reproduction process. Also, the researchers found that entire colonies of bees that come in contact with the insecticide stopped growing, compared to the colonies that have not been exposed to it.
A team of scientists from Sweden has conducted the study on bees to see how they react to the substances.
The researchers used 16 patches of landscape to conduct their study. On eight of these patches the researchers sprayed the canola seeds with pesticides, while the other eight were left unsprayed. Then the researchers compared the results.
Maj Rundlof, a researcher at Lund University and the study’s main author, explained that he was very surprised by the results and did not expect them to be so dramatic.
The study showed that the areas where pesticide had been sprayed, there were half as many wild bees per square meter, compared to the areas that had not been treated.
According to Rundlof, the bees that pollinated the crops with pesticides gained no extra weight, as opposed to the bee colonies from the areas with no pesticides. These bees gained approximately 1 pound, Rundlof said.
European Union banned the use of neonocotinoids in 2013
The use of neonocotinoids has been banned by the European Union and many environmentalists are trying to achieve the same thing in the United States.
The neonicotinoids belong to a class of pesticides that are known for its chronic and acute effects on different living creatures like bees, butterflies, birds and other species of pollinators.
This type of insecticide damages entire plants, making the pollen and the fruit toxic to the species of insects and animals that pollinate them.
The pesticide cannot be broken down easily and can build up in the surrounding environment.
More than 1,000 separate studies on the effects of neonicotinoids have linked these pesticides to the decline of populations of bees, butterflies, earthworms, birds and other wildlife.
The study conducted by Rundlof and his team just before the European Union banned the pesticide use in 2013.
Dennis van Englesdor, an expert in entomology from University of Maryland, who was not involved in the studies, said that the new research is extremely valuable because it showed the damaging effects of the neonics pesticides on the pollinating insects. According to Englesdor, the study done by Rundlof’s team is the most definitive of its kind.
However, the new study conducted by Rundlof and his colleagues could not measure the impact pesticides have on honey bees, only on wild ones.
The researchers believe it could have an effect, but it would be no more than 20%.
According to the experts, every species of bees is different and responds in different ways to the insecticides. Until now, the researchers have used domesticated species of bees as representatives for all species of bees.
Environmentalists are trying to ban the use of neonocotinoids in the United States
The entomologists believe that honeybees, which have colonies of tens of thousands of bees, can actually absorb more losses, as compared to the less sociable wild bees, which have reduced colonies and find it more difficult to get new queens.
Because honeybees are more sociable insects, they are more adapted and are not easily affected by these factors.
According to a study conducted in 2013, wild bees and other wild insects are actually more efficient for pollination, compared to the common honeybees. The majority of wildflowers from around the world are actually pollinated by wild species of bees.
Environmentalists are using the results of the study as proof to convince the United States to ban the use of this class of pesticide in order to save the wild bees population.
Also, more than 4 million people from the United States have signed a petition in which they urge the Obama administration to get involved in this and ban the use of pesticides as quickly as possible.
Scientists published their findings in the journal Nature.
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