Ironically an article published the same date contains information related to AG pesticide use as the factor in question, Multiple Routes of Pesticide Exposure for Honey Bees Living Near Agricultural Fields ... http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0029268

A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis ... http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0029639