Varroa was first identified in 1904 in Java. Since then, it has spread around the world. It first arrived in the U.S. in Maryland in 1979, and reached ‘Oahu in 2007 and Hawai‘i Island in 2008. While mainland beekeepers have learned how to cope with Varroa over the last three decades, Hawai‘i’s beekeepers have only gained experience in the past three years!
Thus, learning from beekeepers in other places can be extremely valuable, as they share what treatment methods have and have not worked. On the other hand, Hawai‘i’s diverse environment makes it more challenging to identify effective treatment options, since bees, pathogens and treatments work differently in different microclimates.
What does not change from place to place, is the immense impact that bees have on humans and the environment. When bee populations decline, it affects the broader agricultural industry because of the crucial pollination services that bees provide. In Hawai‘i, some of the crops dependent on honeybees include coffee, macadamia nuts, melons, tomatoes, cucumbers, citrus, avocado and guava.
There are many different perspectives on how to deal with bee diseases. Some people believe that bees should not be treated at all, and allowed to develop their own resistance over time through the process of natural selection. In Italy, honeybee colonies have been found to build a resistance to Varroa over 10-15 years, but with a population decline of about 95%! Relying on natural selection implies a long ‘return’ time for pre-Varroa population levels to come back.
For this reason, many beekeepers and farmers believe that we cannot wait for natural selection to take effect, since a sharp decline in bee populations would have immediate economic and food security repercussions. At Volcano Island Honey Co., we chose to respond proactively, by experimenting with different organic treatment options even before Varroa reached Hawai‘i Island.
When Varroa hit Oahu in 2007, we applied for a Western Sustainable Agriculture Research and Education grant to do preliminary tests on organic treatment options. Little did we know that shortly thereafter, the mites would arrive on Hawai‘i Island, and our precautionary research efforts would transform into a survival strategy.
As organic beekeepers, we are committed to using no toxic chemicals in our operation. Instead, we established a four step IPM (Integrated Pest Management) method, involving the following steps:
1. Establish a threshold to identify when pest control action must be taken (i.e. 50 mites per hive per day).
2. Use prevention methods as a long-term strategy to combat diseases.
3. Monitor pest levels to identify when an infestation threshold is reached and control methods are required.
4. Implement control methods when prevention is no longer effective or available.
Control methods must be evaluated for their effectiveness and risk, starting with the least risky, most effective option first. As mentioned, because of Hawai‘i’s extreme environmental variation, treatments successful in one microclimate may not work in others — making it more challenging to find an appropriate option for different local conditions. According to Ethel Villalobos of the University of Hawai‘i’s Honeybee Project, the best approach to finding an effective treatment in Hawai‘i is looking at the big picture first, and then narrowing the options down to see what is appropriate for your local circumstances.
Organic Varroa Management & Beekeeper Education in Hawai‘i project sponsored by:
This project was funded by a grant from the Western Sustainable Agriculture Research and Education Program.