Samples from Saipan and Tinian bee colonies are free from deformed wing virus

The University of Guam College of Natural and Applied Sciences (CNAS) is uncovering some very interesting information about honeybee health in the Marianas. Chris Rosario, research associate with the Western Pacific Tropical Research Center at CNAS has been surveying bees on Guam and in the region as part of the Honeybee Health Survey funded by USDA-APHIS.

Rosario has been sampling domestic and feral hives to verify the presence or absence of the parasitic mite Varroa destructor, which uses its piercing-sucking mouthparts to feed on the blood of honeybees and their larva. Beekeepers fear finding the mite in their bee colonies as many bees die or are born with deformities caused by viruses carried by this mite. The Varroa mite spreads the deformed wing virus in bee colonies, which causes wing deformity in honeybees and has a negative impact on their immune systems.

To date, the mites have not been found on Guam, but have been found in some bee colonies from Saipan and Tinian.

Rosario has been sending samples of the Varroa mites he has found on Saipan and Tinian to Dr. Ethel Villalobos at the University of Hawaii. “It is interesting how a region where Varroa mites are found living in bee colonies that neither the bees nor the mites test positive for deformed wing virus,” said Villalobos.

This leads researchers to wonder whether the deformed wing virus is not present in the Mariana Islands or, if the virus is present, whether the honeybees in the region are immune to the virus. “More testing is needed to really understand the ecology of the Varroa mite and bee colonies in the region,” said Rosario.

The good news for Guam is that if the island’s honeybees continue to test negative for the presence of Varroa mites, Guam could be declared free of the mite. “If Guam is in fact confirmed as Varroa free, this could open the door for Guam to supply stateside beekeepers with queen bees certified as free from Varroa mites,” said Rosario. In some states sets of up to 10 queen bees can sell for over $30.00.

Rosario would like people to contact him if they know the location of feral bee colonies on Guam or if they have a domestic hive they would like to have tested for the Varroa mite or the presence of deformed wing virus. He is also happy to talk with people interested in knowing more about beekeeping.

For more information on bees and other topics relevant to plants and animals on Guam, please visit http://cnas-re.uog.edu/bees