 Bumblebees are in danger in many developed countries due to habitat destruction and collateral pesticide damage . The European Food Safety Authority ruled that three neonicotinoid pesticides ( clothianidin , imidacloprid , and thiamethoxam ) presented a high risk for bees . While most work on neonicotinoid toxicity has looked at honeybees , a study on B. terrestris showed that " field @-@ realistic " levels of imidacloprid significantly reduced growth rate and cut production of new queens by 85 % , implying a " considerable negative effect " on wild bumblebee populations throughout the developed world . Low levels of neonicotinoids can reduce the number of bumblebees in a colony by as much as 55 % , and cause dysfunction in the bumblebees ' brains . The Bumblebee Conservation Trust considers this evidence of reduced brain function " particularly alarming given that bumblebees rely upon their intelligence to go about their daily tasks . " A study on B. terrestris had results that suggests that use of neonicotinoid pesticides can affect how well bumblebees are able to forage and pollinate . Bee colonies that had been affected by the pesticide released more foragers and collected more pollen than bees who had not been dosed with neonicotinoid . Although the bees affected by the pesticide were able to collect more pollen , they took a longer amount of time doing so . 
