The buzz on bees
By Neil Reimer
Hawai'i's beekeepers have had the fortune of raising bees without many of the pests and diseases that afflict the beekeeping industry throughout the world. The lack of pests, diseases and disorders such as small hive beetle, tracheal mite, africanized bees and colony collapse disorder has allowed the beekeeping industry in Hawai'i to prosper.
It is easy for the public to overlook the significant contributions of wild and managed bees; however, bees play a crucial role in the pollination of many plants, including those that we eat. In Hawai'i, crops such as cucumbers, watermelon and squash, which are dependent on bee pollination, are estimated at $126 million. Without bee pollination, the value of these crops could decline to about two-thirds their current value. Many Hawai'i residents, knowingly or unknowingly, depend on wild bees to pollinate their backyard fruit trees, such as mango, avocado, lychee and other garden plants. Without wild bees, fruit production would be severely decreased. In addition, the commercial value for the production of honey and beeswax in the state is estimated to be a little more than $1 million and many times that figure for the queen producers in Kona. These queen producers supply queen bees to Mainland and foreign beekeepers that have lost colonies because of pests that are not present in Hawai'i.
There are quarantine prohibitions on the importation of honeybees and used bee equipment to protect the industry. Despite this quarantine, one of the most devastating pests of honeybees — varroa destructor— was recently discovered on O'ahu. It is not known how the varroa mite got to Hawai'i, but its impact to the state is expected to be significant.
Varroa mites are found almost everywhere in the world. It has caused the number of wild bees in some areas on the Mainland to decline by 90 percent, while the number of managed hives declined to half their original numbers. These hives required pesticide treatments and other costly management practices to survive. The mite had an even greater negative impact on organic honey producers, who are not able to use chemical pesticides. We expect to see similar declines in bees in Hawai'i, though the extent of the decline and resulting impacts are not known.
A Manoa beekeeper reported the first find of varroa mites in Hawai'i to the Hawai'i Department of Agriculture in early April. The department immediately worked with beekeepers to survey for mites throughout O'ahu. At the same time, HDOA sent a crew to Kona to survey the major managed hives there, as this is the heart of the beekeeping industry in the state. No mites were found in Kona bee hives.
It was a different story for O'ahu, where the mites were detected in managed and wild hives throughout the island in places such as Honolulu, Nanakuli, Waimanalo, Kahalu'u and Kunia. The surveys also indicate that varroa mites have been present on O'ahu for at least a year before it was reported. Subsequent HDOA surveys on Kaua'i, Maui and Moloka'i have not detected any varroa mites.
The department has been working with beekeepers in the state to develop a strategy to minimize the impact of this new invasive species.
In meetings with the bee industry, there is consensus that mite populations will need to be reduced on O'ahu to levels as low as possible to minimize the risk of them moving to other islands. The mites move from hive to hive by hitching a ride on a bee or on bee equipment. Bees are not able to fly between islands but may hitch rides on boats and aircraft. Under state law, it is illegal to move bees between islands without a permit, and an emergency rule is being proposed to make it illegal to move used bee equipment as well.
HDOA also advised beekeepers to destroy heavily infested hives and to use an EPA-approved pesticide on lightly infested hives. Around air and seaports, the plan calls for the destruction of all infested hives and the placement of swarm traps and poisoned baits.
Although there are a few beekeepers who are strongly advocating total eradication of all wild and managed bees on O'ahu, the fact that the mite is widespread throughout O'ahu means eradication is not feasible nor practical. And any serious effort to kill all wild bees would also adversely impact populations of other beneficial and native insects.
It is also critical that mites are detected early if they do make it to other islands. The state's plan calls for extensive periodic surveys on all uninfested islands to find new infestations and destroy them before they have had a chance to spread.
We hope that the varroa mite infestation was discovered early enough on O'ahu so that it can be contained and prevented from spreading to other islands. This will only be accomplished through cooperation among beekeepers, the department and the public.
Neil Reimer is the Plant Pest Control Branch Manager for the Hawai'i Department of Agriculture. He wrote this commentary for The Advertiser.