Commercially-bred bees -- which are used to pollinate plants in greenhouses -- may be the cause of the drop in wild bee population, according to a Reuters story published today.

Most of the parasites in the wild bumblebees were found to be at normal levels except for one intestinal parasite known as Crithidia bombi that is common in commercial bee colonies but typically absent in wild bumblebees.

The researchers found that up to half of wild bumblebees near the greenhouses were infected with this parasite.

http://www.reuters.com/article/scienceNews/idUSN2232266420080723?sp=true