Northeast bee population declines confirmed

Northeastern bees have suffered population declines over the last century and a half, largely due to human encroachment, which has fragmented their environments. But none has faced a more devastating, rapid and recent collapse than the genus Bombus - the humble bumblebee - say entomologists in the Proceedings of the National Academy of Sciences online, March 5. Combing through the Cornell University Insect Collection - with some 7 million insect specimens representing more than 200,000 species - and other collections, such as the American Museum of Natural History in New York City, Rutgers University and the University of Connecticut, entomologists were able to track patterns of bee abundance in eastern North America over 140 years. "Our goal was to database all major bee collections from the northeastern United States - and to seek trends in relative abundance over time," said co-author Bryan Danforth, Cornell professor of entomology. "Indeed, there are declines among some bee species - host-plant specialists, in particular, are worse off than generalist bees, and several species in the genus Bombus appear to have declined rapidly in the most recent time periods. "This study shows how important natural history collections are for documenting and studying long-term trends in plants and animals over time," he said. Studying more than 30,000 museum specimens representing 438 bee species present in the Northeast from 1872 to 2011, the researchers found slight declines in the number of bee species over time.