A new study from Harvard's School of Public Health claims has revealed that pesticides are responsible for massive collapse of bee colonies. The research found that chemicals present in pesticides affect the immune system of the bees. Colony collapse disorder (CCD) is killing growing number of bees and demands to take curative measures to ensure enough number of bees for pollination, said researchers.

CCD is on rise since 2006 and beekeepers have now realized that it is leading to a situation where only few bees will be left. After suffering from the disorder, only few bees are left in a colony, as the bees disappear and die in abundance. The issue must not be trivialized, given the fact that one third of all food and beverages comes from crops pollinated by honey bees.

Researcher Chensheng and colleagues have found that a class of insecticides called neonicotinoids - banned by European Union for two years - has increasingly worsened the plight of bees. Use of neonicotinoids has increased in the US, which has led killings of more and more bees because of inflicting CCD. The researchers found that pesticides lead to impairment of honey bee neurological functions, specifically memory, cognition, or behavior.

The latest study has concurred with previous findings that found a link between chemicals used on crops with colony collapse disorder (CCD). However, researchers previously believed that disease, parasites, stress, and lack of access to food sources are the likely factors to kill the bees in the US.

The US Department of Agriculture made an announcement in February that it is granting $3 million for strategies to protect the honey bee population.

Experts have said that more researches are needed because exposure to small doses of neonicotinoids did not have any adverse effects on bees. Neonicotinoids seems to be causing some other kind of biological mechanism in bees that in turn leads to the CCD.