What is the Varroa Destructor Mite?

Whether you’re just getting started in beekeeping or have been at it for years, you’ve likely heard a LOT about the Varroa Mite. But are they really as bad as they sound? Should you be concerned?  

The short answer is yes to both questions. A varroa mite infestation can quickly decimate even the healthiest of colonies and you should be concerned!  

But knowing and understanding what the Varroa Destructor Mite is can help you gain confidence in the prevention and treatment of possible mite infestations in your honeybee colonies.  

What exactly is a Varroa Mite?

Varroa mites are a relatively recent concern in beekeeping. Though they are small, they can become a big problem if your hive becomes overrun.  

Here are some quick facts about Varroa Mites:  

  • The typical female varroa mite is around 1.1 mm long and 1.5 mm wide and has a dark red/brown color 
  • Males are smaller, at about 0.7 mm x 0.7 mm, and a light tan color 
  • The lifespan of the varroa is highly variable, ranging from about 25 days to as much as 5 months, with the timeline strongly related to the presence of brood 
  • The original species discovered in 1904 (Varroa jaconsoni) is a parasite of the Asian Honeybee (Apis cerana). For a long time, it was considered to be the same species as Varroa destructor, which is a parasite of both the Asian and the European Honeybee (Apis mellifera). But Varroa Destructor is now understood to be a separate species and the one that concerns us most. 

Though Varroa mites were originally detected over 100 years ago, it’s a relatively recent threat to beekeepers in the U.S., the first Varroa Destructor mites weren’t detected in the U.S. until 1987. By now, the Varroa mite’s threat has become a worldwide issue, and just about anywhere in the world where honeybees are, you can assume they have Varroa mites there, too.  

Understanding Varroa Mite Behaviors & Lifecycle 

Just like knowing how a honeybee’s lifecycle works can help you figure out what’s happening in the colony and how best to care for your bees, knowing how the Varroa mite lives and reproduces can make a huge difference in knowing how to mitigate the issues and damage they can cause.  

Varroa mites come into contact with honeybees while they are out foraging and visiting flowers, either when a worker bee comes into contact with a bee from another colony (like when robbing is occurring) or when a worker visits a flower or plant that happened to have a Varroa mite on it. The mite hitches a ride on the worker and enters into the hive when she returns home.  

For beekeepers, another well-intended task could help mites get from one infected colony into a healthy one. If a beekeeper exchanges frames with bees and brood from one colony into another to help give them brood and resources, mites can easily be transferred with them.  

*Take caution when catching a swarm and bringing it into your bee yard! The bees could be carrying mites that will then have a much easier time and closer proximity to encounter your bees and transfer those mites!  

The Phoretic Stage

A varroa mite NOT underneath a capped cell is in the “phoretic” stage of life. This means they’ll be moving around inside the hive either on the frames and combs, or on the body of a bee, usually on the underside of their abdomen. Mites seen on top of bees can indicate a high mite load within the colony. While mites are on a bee, they’re likely feeding on the honeybee’s hemolymph (aka bee blood, almost like a bee flea).  

The Varroa mite’s main goal, like most insects and wildlife, is to find a safe space to reproduce and raise their young. A honeybee hive is the perfect place for them to do so! It provides the warmth and food they need to survive, reproduce, and thrive.  

After hitching a ride on and possibly feeding on a worker bee, the varroa mite will roam around the hive looking for the perfect place to lay her eggs. Unfortunately for our honeybees, a brood cell, specifically a capped cell, is the absolute perfect place for her to do so.  

Mites enter an un-capped worker cell around 20 hours before it’s capped, or a drone cell up to 40 hours before capping. They hide under the royal jelly within a cell using a snorkel-like apparatus to breathe. This allows them to go undetected by nurse bees, who would normally remove them.  

Mites then will remain under the capping until the bee emerges, reproducing and creating more mites.  

During the phoretic stage, mites may move from bee to bee within a colony, feeding for around 10 days before they enter a cell to reproduce.  

The Reproductive Stage 

Around three days after a female varroa mite enters the cell, she will lay her eggs and also feed on the honeybee pupae. She may also transmit viruses contained in her saliva through the open wounds to the pupae. We’ll go over the viruses and diseases they share with honeybees in a later Snippet.  

As her babies grow from eggs to adult mites, they also will feed on the honeybee pupa. Varroa mites will often choose drone brood cells over worker cells as they are larger, and drones remain under the capping for 3 days longer than workers, allowing more mites to reach maturity before the bee emerges. From one mite entering a worker cell, approximately 2-3 mites will leave, whereas between 3-4 mites emerge from a drone cell.  

Then, The Cycle Repeats Itself

After mites have reached maturity, they will hitch a ride on a worker or drone bee as they emerge from the capped cell. From there, the cycle starts over again and the adult mites feed on bees within the colony or hitch a ride to another beehive to find cells to reproduce in.  

Take a read through our PerfectBee Snippet “Varroa Mites & Honeybee Viruses“, where we cover the viruses and diseases that Varroa Destructor mites can transmit to honeybees and the impacts they have on your colony’s health.  

Learn More

We’ve compiled some of our free resources below, with articles, guides, lessons, and blog posts specific to the dreaded Varroa Destructor Mite.  

As is the case with most beekeeping tasks, there are special tools and pieces of equipment that can help with managing Varroa mites in your bee yard. Check out the PerfectBee Store to find all of your Varroa mite testing, management, and treatment needs. Here are a few of our favorite options:

  • Varroa EasyCheck – For measuring a mite count using the alcohol wash method.
  • Sugar Roll Testing Kit – For assessing mite count using the sugar roll method.
  • Oxalic Acid Kit – A kit that gives you all you need to complete an oxalic acid dribble
  • Drone Frame – Adding a drone frame to your hive can help manage varroa mite levels, but only if timed perfectly right before the drones inside emerge and a ton of mites emerge with them!
  • The Langstroth Screened Bottom Board and Varroa Monitoring Tray – Use the screened bottom board with tray to take a 24-mite count by counting how many phoretic mites fall off of bees within that time period
  • A Field Guide to Honeybee Maladies – An excellent guide to many honeybee viruses, diseases, and pests. Includes information and photos of Varroa Mites and the issues they cause.

Colony-Member Resources:

Colony members, check out these member-only Academy lessons to learn even more about Varroa Mites:

And head over to the Colony Forum to view some interesting discussions specific to Varroa Mites:

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