Varoa destructor mite

      The Varroa destructor mite is the number one killer of honey bees. It first infected Asian Honey Bees (Apis cerana) hundreds of years ago. As the European Honey Bee (Apis mellifera mellifera) moved into Asia, the mite jumped ship over to the European bee.

     The Apis cerana, having been exposed to the mite over the years, was able to genetically shift some behaviors to alter the course of death to one of a means to detect and eliminate the mite.

     Yet, the European Honey Bee, which was imported in the colonies around 1630, has not had sufficient time to alter its behavior to survive as the Asian has.

     The Varroa destructor mite is totally reliant on the lifecycle of the honey bee. This lifecycle begins with the honey bee queen laying an egg, which thrives for three days. It then transforms into a larva in the brood cell. The cell is then capped with wax on Day 9 from the time the egg was laid.

     In order for the mite to replicate it must do so in the honey bee brood cell. If there is no brood, the mite finds itself unable to replicate, thus the population diminishes to zero.

     The honey bee larvae emits a smell twelve or so hours before being capped with wax. The smell (signal), entices the worker bees to cover the cell with wax. Unfortunately, the same signal is noted by the mite so she may jump into the cell just prior to the capping.

     Nature is absolutely amazing!

     The mite, in order to not be detected, scurries beneath the honey bee larva, to hide from any worker bees. If she were to be detected, the nurse bees would not cap the cell, thus preventing the mite from reproduction.

     There is a pool of liquid that the larvae rests in that is the nutrition feeding it. The Varroa mite lays on its back. On its belly there is a snorkel enabling the mite to breath.

     Seventy hours after the honey bee brood cell is capped, the Foundress (mother) mite lays her first egg, a male. Then every thirty hours lays another egg, a daughter. The mite egg matures into an adult in about six days.

     While the mite is in the brood cell, it nourishes on the Fat Tissue of the larva. The Fat Body is composed of protein cells. These cells perform similar to our liver filtering to reduce toxins. It also contains a substance called Vitellogenin which performs several functions similar to human white blood cells. The Vitellogenin combats bacteria, funguses, viruses, and cancer cells.

Essentially, the mite’s nourishment on the Fat Body diminishes the combat ability of the bee against infections. It weakens the honey bee’s health.

     The Varroa destructor mite, similar to the mosquito, regurgitates into the wound site; in order to liquefy the protein cells so it may suck it back in liquid form. The act of regurgitation injects viruses into the larvae.

     The Varroa population is capable of doubling in size every month. The honey bee population increases from fifteen thousand in January to sixty thousand by June. By July, the bee population begins to decline. It is this peak in bee colony size where the mite numbers peak over the bee numbers.

     It is this point the viral loads also have strengthen to the point of impacting the honey bee colony. Beekeepers are often heard to relate in September / October how their hive was robust last week but this week has crashed.

     Last month the article concerned pesticides. An effort by the agricultural community to maintain crop health. The Varroa destructor mite entered the United States in Florida around 1987 causing almost forty years of destruction.

     Several miticides (pesticides) have come and now are gone. The bee community is relatively small in comparison to the agricultural community. The cost to certify a miticide is enormous, with a small market to compensate those costs.

That monetary issue is coupled with the beekeeper that struggles to create a robust annual management plan to effectively mitigate the mite loads, which in turn reduces the viral loads.

     Beekeeping in the fifties merely dealt with honey extraction and colony swarms. Today, the beekeeper is consumed with a battle to keep their colonies alive as the Varroa decimates the girls’ population.

     Honey bee colony losses are increasing each year. The almond industry, which requires over two million hives annually to pollinate them, is struggling. The Columbia Gorge agricultural community has not felt the impact as yet.

     Will the beekeeping industry come together to find a viable, economic solution to alter the course of destruction?

     Consider dispensing a few dollars toward Project Apis m in support of their funding (https://www.projectapism.org/partners/#give).

     The Columbia Gorge Beekeepers Association meets on the third Wednesday of each month, www.gorgebeekeepers.org, at the Hood River Extension office at 6 p.m. A different subject is presented by an nntomologists or experienced beekeeper. All are welcome. Visitors may attend in person or via Zoom. You may reach out to the club for login information — admin@gorgebeekeepers.org. You may also enjoy a visit to the Hood River Extension to view the three bee hives maintained by the Columbia Gorge Beekeeping Club and financially by the Hood River Master Gardeners, Klahre House and the Columbia Gorge Beekeepers Association.