As news of the discovery of the Varroa jacobsoni mite in honeybee hives across Oahu rippled throughout the state, waves of fear rushed through the Maui’s honeybee industry. First discovered in Manoa and Makiki in early April, the parasites have since been found ravaging honeybee colonies all over Oahu.
Tiny, blood-sucking vampires, the mites feed on the blood of honeybee adults, larvae and pupae, causing emerging bees to be deformed, weakening adult bees and slowly sapping the strength and vigor from a hive. Transferred from hive to hive, these pests threaten not only the health of managed and feral honeybee hives and this sweet industry, but also the health of many of our food crops.
“Looks like we’re screwed,” was Maui beekeeper Dennis Morihiro’s summation of the news. A commercial beekeeper on Maui for the past 20 years, Morihiro owns Tropical Apiary Products of Maui with his daughter Courtney.
First discovered in bee colonies in Wisconsin and Florida in 1987, within a year the parasite appeared in 12 states and has since spread throughout the continental U.S. The parasites have since destroyed many beekeepers’ hives and wild honeybee colonies across the mainland.
Rapidly spreading worldwide like a flame in a dry field, Hawai‘i was one of the few places where the mite was not found—until now.
Maui County apiarists are somewhat of a secret society. Beekeepers are not registered or certified in the state. As frequent victims of agricultural theft, beekeepers protect their hives and equipment from bee bandits by not making their locations public information. But Dennis and Courtney agreed to speak with me.
Down an old Kahului alley, sized for a 67-inch Model T Ford, is Dennis Morihiro’s house—the same one he grew up in. Stacks of disassembled beekeeping frames, assorted bee keeping equipment and straggler honeybees buzzing around pretty much give away the location. Inside, the three of us sat at the kitchen table adorned with a bottle of their Christmas berry honey glowing amber in the morning light.
“These mites will change beekeeping in Hawai‘i forever,” Dennis told me as he described the arduous steps needed to control mites once they infect managed hives. Mitigation is expensive, labor-intensive and time-consuming, requiring regular and heavy application of pesticides. And that means the end of organic honey.
Currently in Hawai‘i, the only permitted pesticide for killing mites is Apistan. But according to Neil Reimer, the Plant Pest Control Branch Chief with the Hawai‘i Department of Agriculture, this is just a temporary band-aid. “Mites have developed resistance to Apistan on the mainland, and will also in Hawai‘i,” he said.
Morihiro owns hundreds of hives across Maui. If the varroa mite reaches the Valley Isle, the increased workload makes Dennis wonder if it’s worth staying in business.
“This is very scary,” Courtney nervously told me. “We feel helpless, like parents watching their kids fall down. You want to stop it, but you can’t.”
Maui County appears safe for now. In May, Hawai‘i Department of Agriculture Entomologists surveyed Morihiro’s hives and various apiaries on Molokai and found no varroa mites. While relieved, Dennis and Courtney have little faith the Department of Ag will be able to contain the mites on Oahu.
No one really knows how the mites first came to Oahu. Infested ships and shipments of bees through Hawai‘i are possible sources, though state law does not allow the importation of bees or used beekeeping equipment. Anyone caught smuggling pays heavy fines. But there’s inadequate inspection for cargo coming into Hawai‘i and the federal government allows the trans-shipment of bees through Honolulu from areas like New Zealand, where the varroa mite is already well-established.
In the last decade, tourists have made it from the mainland to here with bees in their pockets. In response to the discovery of the varroa mite across Oahu, the Dept. of Ag’s Plant Quarantine Branch issued a quarantine order preventing the inter-island movement of bees and beekeeping equipment.
“It only takes one infested bee to fly off from the shipment of packaged bees to create problems,” Courtney said. “There are many instances where people and packages are slipping through the cracks.”
There is no question the varroa mite will have a devastating effect on feral honeybee populations. “The varroa mite will attack feral honeybees, too,” Reimer of the Department of Ag said. “The mite has killed about 95 percent of the feral honeybee colonies in the mainland.”
Knowing that honeybees are an introduced species—even considered an invasive species—many native Hawaiian plant experts don’t necessarily consider this bad news.
Honeybees, Apis mellifera, arrived on Oahu in the 1850’s. Beekeeping became popular in the 1890’s, primarily to support the new cattle ranching industry. Needing feed to sustain large cattle populations, ranchers identified kiawe as a good source of food. To increase kiawe bean yield, they established honeybee hives near ranching operations to promote pollination. The kiawe forests quickly spread due to the bees’ busy work.
Spreading invasive species is one reason native plant experts don’t necessarily support honeybees here. Another is that honeybees negatively impact native Hawaiian Hylaeus, or “yellow face” bee populations.
“While honeybees pollinate a few plants that were originally bird-pollinated, where the birds are now extinct or highly restricted, as far as Hawai‘i’s native species are concerned, honeybees are overwhelmingly bad for native ecosystems,” said Karl Magnacca, a postdoctoral researcher at UC Berkeley and an expert on native Hawaiian Hylaeus.
“Hawai‘i’s native ‘yellow face’ bees are solitary bees and do not form colonies,” said Patrick Alridich, a graduate student at the Department of Zoology University of Hawai‘i, Manoa studying the pollination systems of dry forests on the Big Island. “Thankfully, this means the varroa mite won’t effect on native bees; the varroa mite is highly adapted to live in the social conditions of honeybees. The females, depending on species, nest either in wood and twigs or in the ground. They do not make honey. They collect pollen that is used to line the nest and feed the young.”
Honeybees are nectar-robbers on a lot of native plants—they take the nectar without pollinating the plant.
“Honeybees have long tongues that can reach a lot deeper in a flower than the short-tongued native bees,” Magnacca said. “They also have stronger jaws and will cut a hole at the base of a flower that’s too long for their tongue, so they can still get at the nectar. The end result is that there’s nothing left for the native bees that would be doing the pollination.
“The Hylaeus almost never visit non-native plants,” he added. “If an area is dominated by aliens, you won’t find native bees. And they also seem to require multiple kinds of plants, so if there’s just a lot of ‘ohia or naupaka along with a bunch of alien plants—which is often the case in dry forest and coastal areas—you won’t find [native] bees even though those are two of their favorite flowers.”
This serves as another blatant reason to protect the last few intact endangered native Hawaiian ecosystems on Maui. Anna Palomino, a native plant expert who owns Ho‘olawa Farms in Haiku, one of the island’s largest native plant nurseries, can attest to this. “I have observed honeybees on many natives such as ‘ohia, nehe, naio and a‘ali‘i,” she said.
Honeybees can also spread invasive plant species, which alters ecosystems. “Honeybees are doing a whole hell of a lot of pollination for bee-dependent invasive plants like strawberry guava,” Magnacca told me. “A lot of those are totally dependent on bee pollination in their native range, and probably wouldn’t be so weedy in Hawai‘i if honeybees weren’t around to pollinate them. On top of directly competing with native bees for nectar and pollen, they also help destroy their habitat and replace it with one that only the honeybees can use.”
According to UH researcher Aldrich, habitat fragmentation and loss, decline of native plant populations, loss of wood boring beetles (for nests), introduced ungulates and introduced ants—basically the typical culprits for species decline on islands—have all contributed to the trouble facing native yellow face bees. Half of them are endangered or already extinct.
While you can argue that the loss of the honeybees in Hawai‘i could have a positive effect on the native species and ecosystems, it’s also true that honeybees play a critical role in pollinating many of our food crops.
Honeybees are recognized as the single most important and efficient insect pollinators of food plants on earth. Healthy bees are essential for crops that require honeybees for pollination.
Not only do honeybees efficiently pollinate invasive species like strawberry guava, miconia, kiawe and eucalyptus, they also efficiently pollinate strawberries, zucchini, cucumbers, melons, coffee, macadamia nuts, avocados, mangos, lillikoi and coconut, as well as many palms and flowers. These crops depend on feral honeybees for propagation.
If the varroa mite makes it to Maui and infests our wild honeybee colonies, it’s possible we can say goodbye to a substantial portion of Maui’s agriculture industry. The alternative—as is now the case in the mainland where the mite has wiped-out the feral colonies—commercial hives will have to be loaded on trucks and driven around to pollinate agriculture crops.
“The only way to keep them [the mites] out of Maui County is to do 100 percent inspection of all inter-island vessels for swarms of bees or used bee equipment including all cargo shipments, cruise ships and the Superferry,” Dennis Morihiro said. He added that on two occasions he’s had to remove swarms of bees from the decks of inter-island cruise ships. MTW