What is Integrated Pest Management?

As we all know by now, the Varroa mite is one of the greatest threats that a honeybee colony could face. We went over a little bit about just what a mite is and how they live within a honeybee hive in our PerfectBee Snippet, “What is the Varroa Destructor Mite?” 

In another Snippet, “Varroa Mites & Honeybee Viruses“, we covered how mites are a threat not just for the direct impact they have on an individual bee by feeding on its hemolymph (bee blood), but especially because of the viruses that they transmit to honeybees. As they remain in a hive, reproducing under capped cells, they continue to pass on viruses with new mites and new virus transmission impacting the emerging generations of honeybees.  

The combination of varroa mites and viruses within a colony is the leading cause for a colony to perish, so the threat of Varroa mites is a scary thought for any beekeeper. But with proper planning and management of your colonies, there are many ways to go about preventing and managing an infestation in your bee yard.  

What Integrated Pest Management is All About

Though honeybees are incredible creatures and do have innovative approaches to fend off attackers and pests within their hive, beekeepers must sometimes intervene to help maintain colony health.  

The most effective approach to mitigating risks from any pests and parasites that could impact your honeybees is by using an Integrated Pest Management (IPM, for short) system. 

Integrated Pest Management is essentially the use of a variety of techniques that are aimed at preventing, tracking, controlling, and managing pests and/or parasites present within a honeybee colony.  

There are IPM strategies available to combat a wide variety of threats that bees face, and it is especially impactful when used to combat a varroa mite infestation.  

It’s nearly impossible to prevent your honeybee colonies from bringing varroa mites into their hive, but preventing mite populations from increasing to a damaging point is possible by using an IPM system. By using IPM year-round, you can be aware of mite levels and be proactive in keeping the population low.  

Integrated Pest Management for Varroa Mites

Integrated Pest Management requires careful monitoring to be completed by the beekeeper on a consistent schedule. The data collected during monitoring for varroa mite levels is used to evaluate extremely important information within your hive, like how many mites are present and whether the number changes over time. It can also indicate if mites and mite-related viruses are impacting the colony’s health. If you find that mite levels are high enough to require treatment, continuing to monitor them after it has been applied can tell you if the treatment was effective.  

Monitoring for varroa mites should be done consistently, all year long in some places, but especially between March and October in colder climates. Planning and using a calendar to schedule your mite counts can make it much easier to keep monitoring regularly and help you to better plan to have any equipment, tools, or treatments on hand at the time you need them.   

Keep in mind that even if you haven’t had an IPM system in the past and have had no issues with mite infestation, it’s still important to test for varroa mites frequently to make sure that you don’t need to do something different to manage mite levels.  

Testing Methods for Obtaining Varroa Mite Counts

Many beekeepers incorrectly believe that if they “can’t see the mites” in their hive, they don’t have a problem. Since varroa mites live and reproduce within honeybee cells, they are not very often seen on adult bees. It’s very unlikely that you’d spot a tiny mite among thousands of bees within a hive. If you do spot a mite, then you’ve REALLY got a problem.

IPM and monitoring for varroa mite levels should be completed monthly whether you are aware of the presence of mites or not. Since most colonies will have varroa mites living amongst them, knowing what the counts are makes a huge difference in your ability to help your bees thrive.

Simply looking at the bees in your hive for the presence of varroa mites or by looking on your sticky board is not a reliable technique to monitor for mites as it only counts potential phoretic mites, a very low percentage of mite populations.

Two of the most reliable and accurate methods to test for varroa mite counts are:

  • The Alcohol Wash Method – The alcohol wash method is the most accurate mite test available. It involves taking a sample of roughly 300 bees, or about 1/2 a cup, from brood frames (see below for more details on sampling bees) and scooping them into a container designed for alcohol washes. You then add alcohol or windshield washer fluid and roll it around, killing the bees and mites in the process. The alcohol wash container will have a screen through which mites can pass but bees remain, allowing you to count the mites that have fallen off of the dead bees. Divide your mite count by 3 to get the count per 100 bees.
    • Though this method sadly does kill the sample of bees, if the colony is strong and healthy, the impact on their population is often found to be minimal, and worth it to be able to obtain more accurate measurement of mite counts. See the “Learn More” section below for links to alcohol wash testing equipment. 
  • The Sugar Roll Method – The sugar roll method involves taking a sample of roughly 300 bees, or about 1/2 a cup (see below for more details on taking a sample of bees), and scooping them into a wide-mouth mason jar. Powdered sugar is added to the jar and as it’s gently rolled around, the sugar rolls onto the bees and dislodges the mites that are attached. The jar of bees is then shaken over a white surface through a mesh cap design to let mites fall through but not bees. Count the mites and divide the number by 3 to get your mite count per 100 bees. See the “Learn More” section below for links to sugar roll testing equipment. 

No matter which method you choose, WHERE you take the sample of 300 bees from is very important. Since mites hide in cells with older larvae (that are about to be capped), you should ensure to take the sample of 300 nurse bees from brood frames with open brood and older larvae.

Important Note: Be careful to ensure you do not include your queen in your testing sample. Even the gentler sugar roll method could damage or kill a queen if she’s accidentally mixed in.

A less accurate method to get a rough idea of mite levels can be completed by using a screened bottom board and tray. Simply pull out the tray underneath the screen, wipe away all debris, and add oil (like olive) to the surface of the corrugated tray. Wipe it out evenly so that any debris and varroa mites that fall or are groomed off bees will stick to the tray. Come back in 24 hours, pull out the tray, and count the number of fallen mites.

Though this method is less accurate, it can be done with little disturbance to the bees and frequently. Continually completing 24 hour mite counts can at least give you an idea of a possible increase in phoretic mites within your hive. Find a Langstroth screened bottom board and tray under the “Learn More” section below.

Treatment Threshold

You’ve tested your sample of nurse bees and have obtained a “mite count”, but what does that number of mites indicate for your colony?

If the mite count is above the recommended treatment threshold, intervention is needed, and treatment should be applied.

Treatment thresholds vary based on your region, so check with the USDA or your state’s agriculture department for more details on your specific location.

A general guideline for mite count treatment thresholds is as follows:

  • During the months of April to July, the recommended treatment threshold is 2% or 2 mites per 100 bees.  
  • In most areas, during the months of August to October, the thresholds are a bit higher at 3% (3 mites per 100 bees). The higher threshold is because as brood production decreases in the fall, the number of mites in cells decreases but the number of phoretic mites (mites on bees) will increase. Varroa populations also spike in the fall, leading to an expected increase in numbers.  

Genetic Hygienic Honeybee Behaviors and Varroa Mites

One way to help your colonies naturally manage varroa mite populations is to consider adding colonies bred from honeybee stock with Varroa Sensitive Hygienic behaviors. These genetic traits help ensure bees are naturally behaving in a way that aims to rid the colony of mites.

Honeybees bred from stock known to have varroa-resisting behaviors can help control mite levels within the hive more effectively than other genetic lines of bees. They have various varroa fighting methods, most commonly seen through worker bees chewing open and/or perforating cell caps where they’ve detected mites inside or a pupa with virus indications. The opening in the cell cap disrupts the varroa’s reproduction cycle and kills the mites, they can only reproduce under fully capped cells.

If adding a VSH colony to your bee yard is of interest to you, you can requeen your current colony with a Varroa sensitive hygienic queen or purchase nucleus colonies that are bred from varroa-resistant stock.

Regardless of the genetic traits of your colonies, pay close attention and take note of any hygienic behaviors you see when completing inspections, like bees grooming other bees or perforated cell caps. An uptick in these behaviors could indicate a colony that needs mite testing and possible treatment.

Keep an eye out for an upcoming Snippet where we’ll dive into the importance of timing when it comes to managing Varroa mite levels in your colonies.  

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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