PULLMAN Old honeycomb and a new microscopic pathogen quietly spreading throughout the United States are two big contributors to the mysterious Colony Collapse Disorder that has wiped out thousands of hives throughout the Pacific Northwest over the past several years, according to recent research results from WSU scientists.
Working on the project funded in part by regional beekeepers and WSU’s Agricultural Research Center, entomology professor Walter (Steve) Sheppard and his team have narrowed the list of CCD culprits.
“One of the first things we looked at was the pesticide levels in the wax of older honeycomb,” he said. Using combs contributed by U.S. Department of Agriculture, Sheppard found “fairly high levels of pesticide residue.” Bees raised in those hives “had significantly reduced longevity,” he said.
One easy solution is for beekeepers to change honeycombs more often. In Europe, for example, apiarists change combs every three years. “In the U.S., we haven’t emphasized this practice and there’s no real consensus about how often beekeepers should make the change. Now we know that it needs to be more often.”
Another aspect of Sheppard’s work — being conducted by graduate student Matthew Smart — focuses on the impact of a microsporidian pathogen known as Nosema ceranae, which attacks the bee’s ability to process food. Beekeepers have considered it to be “the smoking gun” behind colony collapse.
“Nosema ceranae was only recently described in the U.S., the first time in 2007,” Sheppard said. “But while no one really noticed, it has spread throughout the country.”
Smart surveyed numerous bee colonies in both the Pacific Northwest and in California, and found the new pathogen to be very widespread.
Sheppard’s earlier research found it to be a tough bug to battle. Of 24 hives checked in early 2008, Nosema build-up was high in a majority of the bees sampled. Beekeeper Eric Olson of Yakima said he treated a hive with a mega-dose of the antibiotic fumagillin. “That should have cause the Nosema to either disappear or at least go down, but the levels went up,” he said.
Related:
* 07-20-09 BC Local News, Bees are back as scientists uncover cause of colony collapse disorder
