DURHAM — UNH Extension encourages any beekeeper who has experienced a loss to utilize the Deadout CSI Checklist developed by the New Hampshire Beekeepers Association (NHBA) and NH Honeybee Diagnostic Network. The tool will walk beekeepers through a set of questions and items to look for to understand the possible causes of the loss. Additionally, the NH Apiary Inspector is available upon request to discuss or inspect beehives.
If bees suddenly absconded this fall, keep in mind a few considerations. Varroa mite control and monitoring throughout the season is critical. Mite monitoring by the naked eye is not as effective as the mite likes to feed between the segments on the underbelly of a bee’s abdomen, out of sight. They may also be hiding in cells, feeding on the immature bees (pupae). If you see mites on your bees during a casual inspection, you already have a heavy mite load. Proper monitoring can only happen with a sugar roll or alcohol wash. Refer to the Honey Bee Health Coalition for varroa management and monitoring: https://honeybeehealthcoalition.org/varroa/
Monitoring should occur both before and after treatment to ensure that the treatment worked. The 2019 mite monitoring project (https://www.nh-honeybee-health.com/mite-testing) showed mite counts spiking at all times throughout the summer season. While, traditionally, mite populations peak inside the hive in late August through October, there may be additional spikes in your own hive at other times throughout the season. A single treatment may not be effective for full seasonal control of the mite.
Why did your bees disappear in the fall after being strong all summer? Often disappearing bees can be a result of high virus load caused by varroa mites vectoring (transmitting) diseases such as deformed wing virus or parasitic mite syndrome. In addition to the stress from varroa mites, the bees have been challenged by the drought of 2020 which led to low nectar supplies and poorer nutrition than we are used to in ecologically diverse New Hampshire.
A healthy bee gut, low mite levels, and proper nutrition is the best defense against the many ailments our bees face. Keep in mind the four essential principles of hive management: nutrition, a young productive queen, protection from climatic conditions, and disease-free conditions (through effective monitoring and treatment) to be successful in beekeeping.
Visit the NH Honeybee Health Site to download the Deadout Checklist: www.nh-honeybee-health.com/deadout-autopsy. Visit the NH Division of Plant Industry, Apiary Program to request a visit from the apiary inspector: www.agriculture.nh.gov/divisions/plant-industry/apiary-beekeeping.htm or at 603-271-2561.