Penn State U. researchers are using funding from the U.S. Department of Agriculture to determine what is causing a massive drop-off in the honeybee population.

Honeybee colonies across North America are experiencing a breakdown as bees are dying due to various conditions such as disease or environmental factors. One of the problems facing honeybees is the issue of bees abandoning their hives — a problem called Colony Collapse Disorder (CCD).

Dennis vanEngelsdorp, a senior extension associate at Penn State, said CCD is one of the major causes of the decrease in bees — but it isn’t the only one.

One-third of the total number of worldwide honeybee colonies has been lost due to several factors, vanEngelsdorp said. But the proportion of the colonies lost due to CCD has decreased, meaning other causes are to blame.

“It’s not like [CCD] in itself is killing the bees. It’s certainly other things,” vanEngelsdorp said. “The bigger picture is factors that are affecting colony mortality, and certainly one of those factors is colony collapse disorder.”

Now, students and researchers are working in a Penn State lab to determine the effects of diseases, viruses and environmental factors on the honeybee societies.

Christina Grozinger, an associate professor in the university’s entomology department, said the lab’s main focus is to understand the genes that regulate behavior in honeybees and how disease alters social interactions between bees.

Jessica Preston (sophomore-animal science), who works in the lab, said she is researching the effects of Nosema — a fungal disease that affects honeybees — on the hive.

Preston will observe a beehive that contains bees infected with Nosema to see how the infected and healthy bees interact. By observing the beehive, she can determine whether the healthy bees will remove the infected bees from the hive and try to save them or simply leave the hive.

While researchers are still unsure as to the exact cause of CCD, diseases like Nosema could be adding to the problem, Preston said.

“The speculation now is that there are many different causes of colony collapse disorder,” Preston said. “They all work together to kill bees.”

The bee deaths may have a large effect on the human population, too, vanEngelsdorp said — bees directly or indirectly help produce one in three bites of food humans eat. By pollinating crops across the country, the bees have aided in the production of produce.

“If we want to produce fruits and vegetables in this country, then we need a healthy moveable pollination supply,” vanEngelsdorp said. “And the most important pollinator out there is honeybees.”