A Beginner’s Guide to Beekeeping: When to Start Your First Varroa Mite Treatment

If you are new to beekeeping, one of the most important skills you must learn is Varroa mite treatment. Many beginner beekeepers lose their first colony not because of weather or lack of honey, but because of unchecked Varroa mites.

Varroa mites are the number one threat to honey bee colonies worldwide. Learning when and how to begin Varroa mite control can mean the difference between a thriving hive and a premature collapse.

This beginner-friendly guide explains what Varroa mites are, how they kill bees, how to test for them without killing bees, and when to start your first Varroa mite treatments.

What Are Varroa Mites and What Do They Look Like?

Varroa destructor, commonly known as the Varroa mite, is an external parasite that feeds on the hemolymph ( blood) of adult honey bees, fat body tissue, and developing broods. It is considered to be the most destructive honeybee pest and causes the biggest financial losses to beekeepers.  

Before you can begin treating for Varroa mites, you must know what you are looking for. Varroa mites are visible to the naked eye. Here’s what they look like: 

• Color: Adult females are reddish-brown, while males are smaller and yellowish-white.
• Shape: Flattened, oval, and crab-like, often described as scallop-shelled.
• Size: Roughly 1-2 mm in length, similar to a pinhead or poppy seed.
• Legs: They have eight legs that extend outward from the front of their body.

They often appear on the bee’s thorax or between abdominal segments. Inside brood cells, they reproduce on developing pupae.

If you can clearly see mites crawling on adult bees, the infestation is already heavy. That means you should immediately start honeybee Varroa mite treatment.  

How Do Varroa Mites Kill Bees?

Varroa destructor mites kill honeybees by feeding on their fat body tissues, spreading fatal viruses, and weakening brood development. Due to weak fat bodies, the honeybee colonies collapse prematurely. Varroa mite control is extremely crucial because this destructive mite inflicts the biggest financial losses on beekeepers than any other disease, according to the U.S. Department of Agriculture (USDA). 

1. They Feed on Bee Fat Bodies: According to research, this parasitic mite primarily feeds on the bees’ fat bodies and not just hemolymph (bee blood). Varroa mites damage the fat body, which leads to a weaker immunity, low winter survival ability, and shorter lifespan. 

2. They Spread Deadly Viruses: Mites transmit viruses such as Deformed Wing Virus (DWV). Bees may emerge with shriveled and shrunken wings or shortened abdomens.

3. They Weaken Brood Development: Mites reproduce inside capped brood cells. As they multiply, each new generation of bees emerges weaker. As a result of these damaging effects, colonies gradually collapse. 

What Are the Signs of Varroa Mite Infestation in a New Colony?

Many beginners assume new colonies are mite-free, but even new colonies can have mites. Watch for the warning signs, such as mites on bees, deformed wings, spotty brood, and crawling or weak bees, before starting Varroa mite treatment. Remember, visible symptoms usually mean mites are already established. That’s why you should regularly test for effective Varroa mite treatments. Here are some key signs of Varroa mite infestation: 

1. Visible Mites on Bees: If you see reddish-brown mites on adult bees, it means infestation levels are already high. Start the Varroa mite treatment without any delay if this happens. 

2. Deformed Wings: Bees with twisted or shriveled wings are often infected with Deformed Wing Virus, which is spread by Varroa mites. These bees cannot fly and usually crawl near the hive entrance. This is a strong sign that immediate Varroa mite control is needed.

3. Spotty Brood Pattern: A healthy brood looks tight and uniform. If you see empty cells scattered between capped brood, there is a probability that mites may be weakening developing bees. This often signals it is time to start treating for Varroa mites.

4. Weak Population Growth: If your colonies show slower growth than expected during the spring or summer, Varroa mites may be shortening bee lifespan and slowing brood production. Do not delay bee Varroa mite treatment if you notice sluggish growth. 

5. Crawling or Weak Bees: Bees that crawl instead of flying are often virus-infected due to mite damage. This is a late warning sign.

Even if you do not see symptoms, mites can still be present. That is why testing is critical before deciding on treating bees for Varroa mites.

How to Test for Mites Without Killing Bees?

Many beginner beekeepers hesitate to test because some methods sacrifice bees. While alcohol washes are most accurate, there are gentler options that are non-lethal, such as the powdered sugar roll, sticky board test, and drone brood check. 

1. Powdered Sugar Roll

This is a great non-lethal alternative to the alcohol wash test. Here are the steps to perform it: 

• Gather about ½ cup of nurse bees (around 300 bees) from the center of the brood nest. Make sure the queen is not included.
• Place the bees in a jar with a mesh lid or a Varroa mite test bottle and add 1–2 tablespoons of powdered sugar.
• Gently roll or shake for 1–2 minutes to coat the bees. Let it sit for another 2 minutes so the sugar loosens the mites.
• Invert the jar over a white container or tray and shake firmly for about 1 minute to make the mites fall.
• Count the fallen mites, then return the bees to the hive. Other bees will clean off the sugar.

2. Sticky Board Monitoring

Place a sticky board under the hive on the bottom board for about 3 days. The board will collect mites that naturally fall from the bees. This method is less precise than a sugar shake, but it is non-invasive and useful for ongoing monitoring.

3. Drone Brood Uncapping

This method involves opening the capped drone broods to check inside for mites. Varroa mites prefer drone brood because it stays capped longer, giving them more time to reproduce. This method is good for spotting a growing mite problem, but it is limited to the brood. 

When Should You Start Your First Varroa Mite Treatment?

The most important time to begin your first mandatory Varroa mite treatment is mid-to-late August, after removing your honey supers. This is when your colonies begin raising long-lived winter bees, and mite levels peak. If you don’t control the mites at this stage, they will damage the ‘fat bees’ that must survive all winter.

While late summer is the most critical time, some situations also require early spring testing.

1. Late Summer (August to Early September) 

This is the most critical period for Varroa mite control, because during late summer, mite populations are at their highest. If mites infect developing winter bees, those bees will have weakened fat bodies and shorter lifespans due to weak immunity. 

Even if the colony looks strong in September, it may collapse in winter. This is why most experienced beekeepers consider late summer the most critical time for Varroa mite treatments.

2. Post-Harvest Treatment

Always remove honey supers before applying most chemical treatments for Varroa mites. Products like Apivar require a long treatment cycle of around 8 weeks. Applying treatments while honey supers are on can contaminate harvestable honey. 

3. Monitor Mite Levels Regularly

Do not apply any treatment blindly. Smart beekeeping starts with regular Varroa mite testing. While the Alcohol wash method is the most accurate for testing the Varroa mite level, it kills the bees used in the testing. Non-lethal methods include powdered sugar roll and sticky board. You should begin treating bees for Varroa mites if mite levels exceed about 2–3%,

4. Spring Treatment Option

Some beekeepers also perform a spring Varroa mite treatment, especially if the colony was not treated the previous fall or winter losses were high in the area. An early spring treatment, often in April, can lower mite populations before they explode during brood expansion.

5. Newly Installed Packages

Treating package bees for Varroa mites before or right after installation is strongly recommended. At this stage, there is little or no brood, so treatments are most effective because they target ‘hitchhiking’ mites on adult bees.

The most common method is treating Varroa mites with oxalic acid, applied either as a light spray to the package before installation or as a drizzle once the bees are in the hive.

How Do You Treat Varroa Mites?

There are various types of Varroa mite treatments used in modern beekeeping. The main types include synthetic miticides such as Amitraz, organic acids like Formic Acid and Oxalic Acid, essential oil–based treatments such as Thymol, and manual removal methods. Each type works in a different way and must be used at the correct time for effective varroa mite control.

1. Oxalic Acid (OA)

Treating Varroa mites with oxalic acid is one of the most commonly used methods. It is especially effective when little or no brood is present because it only kills phoretic mites, mites on adult bees. Application methods include vaporization, dribbling, and spray. 

2. Formic Acid

Formic acid is unique because it can penetrate capped brood cells and kill reproducing mites inside. This makes it effective even when the colony has a heavy brood, but it must be applied within specific temperature ranges to avoid harming bees or the queen.

3. Thymol-Based Treatments

Thymol treatments are made from thyme oil and are considered a softer or more natural option for treating Varroa mites. They work best within certain temperature ranges and require proper hive ventilation. Thymol treatments act more gradually and are often used during warmer months.

4. Amitraz (Apivar Strips)

Amitraz is a synthetic miticide delivered through plastic strips placed between brood frames. Bees contact the strips and spread the treatment throughout the hive. The strips remain in the hive for several weeks (usually 6–8). Honey supers must be removed before treatment.

5. Hop Beta Acids (HopGuard)

HopGuard is derived from hops and is considered a plant-based treatment. It can be used during brood cycles, but because it mainly affects phoretic mites, multiple applications may be required for full effectiveness.

6. Manual Removal

This is a mechanical control method rather than a chemical treatment. Since mites prefer drone brood, beekeepers can remove capped drone brood frames and destroy them. Powdered sugar can also be dusted over frames to encourage bees to groom and remove mites.

Final Thoughts

Beginners can tend to delay Varroa mite treatment because the hive looks busy and productive. But mites multiply faster than most new beekeepers realize. Mites can cause strong colonies to collapse in late autumn or early spring if treating bees for Varroa mites is ignored.

Regular monitoring and early detection, especially during crucial times of the year, can help you protect your colonies and extend their lifespan. Successful beekeeping is not just about honey. It is about timely testing, with testing bottles or double-screen jars, and treating Varroa mites before they spread out of control. 

Frequently Asked Questions

How Do I Know When It's Too Late to Treat My Bees for Varroa Mites?

If the winter bee population is compromised to a severe level by mite-induced damage, it's a sign that it might be too late to treat Varroa mites. Signs include spotting many bees with deformed wings (DWV), a rapidly decreasing population, or finding a dead colony. 

Can I Treat for Mites While My Honey Supers Are On?

This depends on the product used, so it is important to know about the product before use. Some Varroa mite treatments cannot be used while honey supers are on because residues may contaminate honey.

What are the signs of Varroa mite infestation in a new colony?

Signs of Varroa mite infestation include visible mites on bees, weak or crawling bees, deformed wings, and spotty brood patterns. 

How do Varroa mites actually kill a hive?

Varroa mites kill a hive by feeding on their blood, fat body tissues, and larvae. This makes the adult bees and the larvae weaker and causes them to die early. 

What is oxalic acid treatment for Varroa mites in beekeeping?

Oxalic acid treatment is an organic and fast-acting method to control Varroa mite infestation. It kills phoretic mites (those on adult bees) by disrupting their metabolism. It can be applied asvaporization or dribble during broodless periods.