By Glenn I. Teves, County Extension Agent, UH CTAHR Cooperative Extension Service
The relationship between humans and honeybees is ancient, as demonstrated by cave paintings in Spain, South Africa, and Nepal, depicting honey hunters collecting honey from wild hives. The honeybee was introduced to Hawaii in 1857, but the accidental introduction of the Varroa mite in 2007 puts this relationship in jeopardy and is one example of Hawaii’s vulnerability to invasive species.
The Varroa mite (Varroa destructor) is one of the most serious pests of honeybees and is associated with the spread of viruses and the decline of honey bee colonies on the mainland. And it’s only a matter of time before it destroys all feral honeybee colonies in Hawaii. On the island of Oahu alone, over 90 percent of the wild colonies have been wiped out and it has now moved to the Big Island, starting in Hilo. Visual checks of feral honeybees in Ho`olehua and Mo`omomi have not found the Varroa mite to date.
The mites attack both adult bees, and also larvae in the hive. Although honeybees in Hawaii are crosses between German, Italian, and Carnolian bees, the honeybees on Molokai appear to be a special disease resistant strain, first brought in around 1898. They show resistance to a disease called Foul Brood, which wiped out honeybees on most of the islands starting in 1908.
Bees are vital to the pollination of many crops, and it’s estimated that without the honeybees in Hawaii, over $60 million would be lost including macadamia nut, coffee, lychee, avocado, melons, and many more. The $6 million Hawaii queen bee export and honey production industry is also in jeopardy. The Department of Agriculture (DOA) Secretary Tom Vilsack stated that “bee health is critical for the success of pollination-based agriculture, which produces about a third of our diet in the United States.”
The UH Honeybee Varroa Mite Project, along with the State DOA, are developing strategies to keep the varroa mite at manageable levels in hives overseen by vigilant bee keepers. It’s not unusual to find 10,000 mites in one hive, and strategies are being developed to keep the mite population below 1,000-2,000 mites per hive. But it doesn’t stop here. The more recent introduction of the Small Hive Beetle in April 2010 on the Big Island has added a one-two punch to Hawaii’s honey bee problems. This beetle turns into the wax moth and will devour wax in hives and in the wild.
The only solution is to raise bees so we can care for them, and prevent these invasive pests and other pests yet to come from wiping them out. Honeybees are very different from wild bees since they have been domesticated and have a hard time fighting off predators. For one, honeybees are not proficient at grooming themselves and cleaning their body. As a result, the varroa mite can attach to their backs. By sprinkling powdered sugar on them as they enter the hive, honeybees will be forced to clean themselves, removing the sugar, and knocking off mites in the process. Another technique is to add a sticky strip at the base of hive entrances to apprehend the mite. This is just one technique being refined, while others involve the use of organic pesticides that don’t affect bees. By better understanding the habits of both insects, sustainable strategies can be developed to keep these invasive species in check. In return, honeybees can continue to provide us with precious honey, pollinate many of our important crops, and ensure our food security on Molokai.