SEATTLE — Honey bees (apis mellifera) pollinate an estimated $30 billion worth of U.S. crops. So their mysterious demise is a real concern to both farmers and consumers.

Recent research has found some probable causes and the results show reversing the trend will be more difficult than first thought.

During the last six years, Colony Collapse Disorder has killed off an estimated 10 million beehives worth an estimated $2 billion.

Suspected culprits have included poor nutrition, pesticides and disease-bearing parasites. However, researchers from the University of Maryland and the U.S. Department of Agriculture have concluded one cause may be pollen contaminated by a combination of pesticides and fungicides.

The research doesn’t identify specific reasons why entire beehives die at once but does shed new light on why bees are dying in such large numbers.

Pollen from beehives pollinating watermelon, cranberries and other crops was fed to healthy bees, which then couldn’t resist infection from a parasite named Nosema ceranae. The pollen had between nine and 21 agricultural chemicals, eight of which were linked to an increased infection risk.

Further, bees eating pollen coated with fungicides were infected by parasites three times more often than other bees. This was alarming as fungicides were regarded as being harmful only to fungus, not insects such as bees.

The U.S. bee population has declined so far that 60 percent of the remaining colonies are necessary to pollinate California’s almond crop alone, which accounts for 80 percent of the world’s almonds.

Source: http://www.prreach.com/pr/2579/