Scientists have discovered a second strain of the Nosema virus may be to blame for rising honey bee deaths.
While more factors are at hand for causing declining numbers of honey bees, these findings may help determine why honey bee losses have become so dramatic within recent years.
According to a recent study released May 27, Nosema ceranae- not to be confused with Nosema Apis- may affect not only adult honey bees, but their developing brood as well.
“Nosema ceranae causes a widespread disease that reduces honey bee health but is only thought to infect adult honey bees, not larvae, a critical life stage,” says the study entitled: “Nosema ceranae Can Infect Honey Bee Larvae and Reduces Subsequent Adult Longevity.”
The study exposed the larvae of honey bees at three-days old to N. ceranae spores within their food.
“Nosema ceranae infection contributes to poor honey bee health globally and is thought to only infect adult honey bees. However, by using controlled in vitro exposure to spores in brood food, we show that N. ceranae can infect A. mellifera larvae,” the authors of the study conclude.
Therefore, this strain of the Nosema virus is capable of shortening the lifespans of both the developing brood and adult honey bees.
What is the Nosema Virus?
The Nosema Virus is a parasite that can affect anywhere between 50 to 90-percent of hives in certain regions, according to Advance Science.
It is a type of fungus that can often enter a honey bee’s stomach through its source of food, affecting the bee’s gut and digestive system.
“There are now two different types of Nosema affecting the European Honey Bee: Nosema apis and Nosema ceranae. Nosema apis has been found in hives since the beginning of the twentieth century but Nosema ceranae was only discovered in the early 2000s,” reports Advance Science.
The two strains of the Nosema virus are reported to show different signs and symptoms.
“Nosema ceranae is different from Nosema apis,” writes Advance Science. “It has no obvious symptoms, is more prevalent in warmer climates, its spores are more resistant to heat and are more sensitive to the cold. Importantly, N. ceranae is not as seasonal as N. apis and tends to build up over years.”
“It (Nosema ceranae) was only first discovered in the European honey bee in Vietnam in 2004, but it probably transferred across to Europe some time late in the 1990s and has been spreading rapidly since,” according to Advance Science.
The fact that Nosema ceranae may be an emerging issue causing a global disaster for honey bees is supported further by ostensibly optimistic reports of higher bee losses during the summer of 2014 than the winter- This defies decades of an ubiquitous trend involving higher bee losses during the winter as opposed to the summer.