David Broyles | The News

Local beekeepers find themselves without a definitive answer to the so-called Colony Collapse Disorder which continues to kill an average of 30 percent of hives across the nation. North Carolina State University Entomologist Dr. David Tarpy says scientists now feel the disorder is due to a variety of causes.

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RALEIGH — The positive outlook of North Carolina State University Entomologist Dr. David Tarpy is admirable in the face of science’s methodical collection of clues to answer Colony Collapse Disorder (CCD) across America among honeybees.

“I think there are several silver linings in the importance of CCD and public awareness is right up there among them,” said Tarpy. “The media’s frantic coverage really presented the importance of bees to our food supply in a way to the public that persists even after the coverage has receded.”

Tarpy indicated the demise of the disorder by merely abolishing one group of pesticides known as neonicotinoids touted in many print articles is premature. He said data available now seems to lean towards CCD being the product of many different factors.

“It (CCD) is still a serious threat,” said Tarpy. “The problem with the single pesticide solution is there have been no reproducible results we can tie to a pesticide. As far as strictly considering CCD studies recently, they (the neonicotinoid family of pesticides) do not seem to be directly involved.”

Tarpy is one of a group of scientists nationally and internationally operating from an apprehension that the disorder is due to a lot of different causes and researchers are not entirely sure yet what all the pieces of the puzzle are and in what combination they must happen to kill the insects.

He said much prevailing wisdom on the subject has first centered on studying the interaction of elements to the disorder’s pathology, parasites and pathogens. Scientists want to determine if the disorder is an unknown disease or an existing disease which evolved into a more deadly form.

Observation on affected hives has proven colonies wiped out by CCD have several types of parasites and diseases but it is not entirely sure if this is the cause, if it is the effect or if these factors merely weaken the colony, making them likely to become sick.

A second factor or consequence researchers including Tarpy are looking at is the impact of nutrition and diet on the bees. The core questions in this line of inquiry is how habitat destruction and the insects’ propensity to concentrate on “working” blossoms of one type of plant until all of the flower’s nectar and pollen is gone before moving to the next plant.

In essence, entomologists are asking if loading up large quantities of bees cross country and placing them in areas where they will work on only one plant, such as almonds, is so restrictive a diet it is harming the bees. Tarpy indicated the third area being examined is the impact of a variety of pesticides on the bees both from beekeepers and farmers.

“All of these factors have contributory effects we must understand in relation to the effects of CCD,” added Tarpy. “It is not one factor that we have been able to identify as a strong cause.” He said losses nationwide continue to hover around 30 percent, or one out of every three hives falling to the disorder.

He said last year the mild winter and some other factors pushed the losses down slightly but he suspects this same weather could set in motion other situations endangering honeybees.

“If I were to make a prediction on the figures before me now, this winter may prove to be a fairly high year for losses,” said Tarpy as he explained the mild season and other factors are an opportunity for pathogens to emerge stronger in the spring. He said because colony survival last year was up, one data point doesn’t make a trend.

“Basically we now have to look at this (CCD) on a case by case basis,” predicted Tarpy. “A multi-faceted approach makes any isolated data we receive not trivial. It also makes it exceedingly difficult to study.”

He disagrees with criticism the industry being too dependant on too few producers of honeybee queens is hurting the species.

“Genetically speaking, we do not seem to have a lot of different populations of bees in North Carolina or North America in general,” said Tarpy. “They are very similar genetically and the practices of many beekeepers has the potential to create a bottleneck and could be dangerous, but there is still a lot of diversity among honeybee populations. There just isn’t enough evidence to directly indicate a lack of diversity has an effect on CCD.”

Tarpy and others like him continue to slowly collect data since it was first identified more than six years ago, hoping this is a riddle they can figure out while there is still an opportunity to save the insects.

Reach David Broyles at dbroyles@heartlandpublications.com or 719-1952.