Pearl City Researcher Contributes To Major Bee Mite Findings
Varroa, external mite parasites of bees, were initially discovered in 2007 on Oahu and were seen on the Big Island a year later.
Researchers from Sheffield University in the United Kingdom, along with Ethel Villalobos and Pearl City’s Scott Nikaido of the UH Manoa College of Tropical Agriculture and Human Resources’s Honey Bee Project have found a link between mites and this destructive honeybee virus.
“The European honeybee is what we use for honey, but this (varroa) is a pest that attracts other kinds of honeybees like the Asian honeybee,” Villalobos explained. “It moved to Europe, then to the United States, and Hawaii was one of the few places that didn’t have it. But we got it in 2007.”
According to the June 8 issue of Science, these researchers observed a large-scale change in the honeybee viral landscape, and their findings could help uncover the mysteries surrounding the colony collapse disorder, in which honeybees suddenly vanish from their hives.
“The mite itself is very damaging because it transmits the virus,” Villalobos explained. “It infects the bees, and they’re born with deformed wings and are unable to contribute to the colony.”
Their research also shows how the dissemination of the varroa mite in Hawaii has led to an increase of deformed wing virus (DWV) among local colonies. Since the mite arrived in the Islands, DWV’s presence in colonies rose from 6-13 percent to 70-100 percent.
Nikaido, who is part of the research support team, explained that varroa is a parasitic mite that feeds on adult and baby honeybees and also will reproduce with the baby honeybees.
“This is where they cause problems in which the young baby bees receive large amounts of DWV when fed upon by the mite. DWV is a virus that is replicated in the varroa mite, and in high levels can cause deformation and shortened lifespan in honeybees,” he said.
DWV is prevalent on Oahu and the Big Island, but Molokai, Maui and Kauai don’t yet have it. Until recently, not much was known about the natural landscape of this virus, but the introduction of varroa in certain parts of the state provided Villalobos and Nikaido a unique opportunity to study the early phases of its evolution.
“Our ‘aha’ moment is seeing how rapidly DWV spread across the Big Island, but also seeing beekeepers respond to the threat,” Nikaido said.
According to Villalobos and Nikaido’s research, honeybees likely show serious signs of infection such as crumpled and unusable wings when the viral transmission involves varroa. Understanding the role of varroa and the changes it causes in the viral strains of DWV is crucial to the protection of our honeybees.
“If the mite is not kept under control, the virus keeps spreading,” Villalobos said.
The researchers found that while DWV normally is a virus of low prevalence and minimal impact in varroa-free areas, the spread of varroa within the state has caused DWV to emerge as a lethal pathogen. From this, they have hypothesized that the affiliation of the varroa mite and certain strains of DWV could be a contributing factor to the deaths of millions of honeybee colonies around the world.
“Once you have it, you have it,” Villalobos said. “You need to learn to treat it to keep it under control.”
Nikaido agreed and explained that controlling DWV can be accomplished in various ways, mainly by using synthetic chemicals or organic methods.
“The best way to control DWV is to control the mite population in the honeybee colonies … We like to have beekeepers use organic methods if possible. Unfortunately, nothing can be done to our wild honeybee population.”
Nikaido and Villalobos will continue to study DWV, and they also are interested in working with local farmers in the polli-nation of local crops and creating pollinator-friendly environments.
For more information, visit the UH Honeybee Project’s website at uhbeeproject.com.
