Finding the best varroa mite treatment plan is a key factor in keeping honey bees healthy. Varroa mites are a leading cause of honey bee colony death. There are no easy answers for varroa mite control. These bee pests continue to kill bees even as beekeepers attempt to help their colonies deal with them. There are several control options but none are perfect.
Are Varroa Mite Treatments Really Necessary?
Varroa mites are external pests of honey bees. This small reddish mite is visible to the naked eye. It looks like a tiny red dot on the bee’s body. But you don’t always see them, they hide underneath the segments of the bee exoskeleton.
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Mites weaken and eventually kill most colonies of honey bees. Without some type of control to keep the number of mites in the hive low, hive failure is sure to come.
Varroa mites are the #1 killer of bee colonies worldwide. Varroa control is not a beekeeping management strategy that can be overlooked. In most regions, colonies without some type of varroa plan will die within 2 years.
We often say – by the time you see mites on the bees, it is too late to save the colony. This is because at any given time, most of the mites are in the brood cells. Don’t wait for visual confirmation.
The majority of our colonies can not deal with varroa on their own. They might survive one year with a heavy mite load .
But, these colonies often fail before the end of the second year. Surprising the beekeeper who believed there was no problem.
In most varroa mite control plans, the goal is not necessarily a complete kill of every mite – rather a reduction in infestation levels.
Ideally, we seek something that works well with no risk of harm to the bees. But even some approved treatments, pose concern about contamination of beeswax or honey.
Mites in Beehives is Nothing New
Finding mites inside a honey bee colony is nothing new. Most honey bee colonies actually have several types of mites in residence. Thankfully, only a few cause problems for the bees and beekeepers.
Several years ago tracheal mites caused major losses to the bee industry. Many beekeepers lost large numbers of colonies.
But in time, the honey bees adapted, those more resistant to the mites lived to reproduce and beekeepers learned how to handle the tracheal mite infestations.
When Should You Treat for Varroa Mites?
Finding the best time to treat a colony for mites will depend on the treatment type chosen and the level of infestation. Weather also plays a role in some of the treatment options.
How Many Varroa Mites are too Many?
While small numbers of mites can have an effect on a strong bee colony, the damage is minimal. As a mite infestation grows larger, problems become more noticeable.
How many mites are too many? It depends. (If you thought I was going to give you a definitive answer, you must be a new beekeeper.)
Those of us who have been around a while know that most things in beekeeping have several answers. ? But, I do have some guidelines for you to consider regarding when to treat your bees for mites. This involves determining the varroa mite threshold and that is often a moving target.
Varroa Mite Treatment Threshold
Over the years, the acceptable number of mites in a hive has changed a bit. Years ago beekeepers were told an acceptable number for a 24 hour mite drop. Each year that number got lower as researchers learned how damaging varroa can be to colony health.
First, you need to get a estimate of the number of mites in your colony. We call this doing a mite count.
There are several methods of doing mite counts. These involve sticky boards, sugar shakes and alcohol washes. Regardless of the method used, testing for varroa mites is critical to saving your hives.
After completing your test counts you will have an idea of the approximate number of mites in your hive.
When the level of mite infestation is in the 2% to 5% range, the beekeeper must make some decisions. Should you treat now or wait and watch?
Immediately treat any hive with a mite infestation of 5% or more. This colony is in crisis and it may be too late already! For myself, if I have a 2% infestation, I would definitely treat.
Why would someone wait? Perhaps they have honey supers on the hive that they want to harvest first? A dead hive may result from waiting too long.
Mechanical Varroa Mite Control
One way beekeepers deal with mites is the use of mechanical (non-chemical) methods. Using screened bottom boards (instead of solid), causes some mites to fall to the ground and perish.
There was high hopes for the use of screened bottom boards in the beginning but I have little confidence in them at this point as a varroa control.
This technique may help but the number of mites killed is a very small amount. This is not enough when used alone to protect your hives.
If you use solid wood bottom boards, you can purchase a sticky board with a screen. This allows you to do a mite count without having bees stuck to the grid board.
Screened bottom boards are great at giving your hive extra ventilation though and I think they are worth the effort in that respect.
Drone Brood Removal for Mite Control
Some beekeepers advise the removal of capped drone brood (the mites favorite host).
Special drone frames can be used to encourage drone production. Once filled with capped drone brood and developing mites inside, the frame is removed.
Freeze the whole frame, killing the mites and the drone brood is sacrificed as well. After thawing, the frame is put back into the hive for reuse.
Personally, I am not a fan of this method. You must remember to remove the frame at the proper time. Otherwise, you have just created a mite maternity ward.
Varroa Mite Treatments Compared
What you choose as your varroa mite treatment for bees is as individual as you. We all keep bees in different ways.
Attempting to maintain a zero-mite count is difficult if not down right impossible. Remember we are trying to keep mite levels low.
As varroa mite numbers grow, colony health declines. Sick worker bees live shorter lives and are not as strong. Viruses such as Deformed Wing Virus are more prevalent.
I tell my students in my online beginners class, how important it is to decide on a varroa mite control plan. Do not let the mite number get out of control.
As the industry strives to breed bees that have more resistance to varroa mite infestations, we use what we have in the current battle.
Approved Chemicals – Practical Treatments for Varroa
Research has provided us with several chemical treatment options. If you choose to use these products, it is important to rotate them.
Varroa resistance to some of these products is reported in the industry. You must use your own judgement when deciding what to put in your hive.
Apistan (fluvalinate) is an older substance used for mite control in honey bees for years. It is an impregnated strip that kills by contact. Strips must be placed inside the hive and then removed after a certain time period.
Reports of wide spread resistance to fluvalinate has been reported in colonies over recent years. Also, chemical residues may persist in beeswax in the hive. Most beekeepers that I know no longer use it.
Apivar (amitraz) is a synthetic miticide that kills by contact. Impregnated strips are place near the brood nest much like Apistan.
This chemical was used for mite control for a while, then pulled and now allowed again.
Apivar has time usage restriction. Do not place honey supers on your colony for at least 2 weeks after treatment.
Low levels of residue can be detected in the beeswax and honey. Mites can develop resistance. Some beekeepers report good results with this approved varroa mite treatment product.
HopGuard (Potassium salt -hops beta acids)
A natural product made from hop compounds – Hopguard (Potassium salt (16%) of hops beta acids).
Honey supers can be on the hive during treatment and that is a plus. But, beekeepers report that it is messy to work with.
Beekeepers in my region have not reported consistently good results using Hopguard. But you may decide to give it a try in your apiary.
Essential Oils for Varroa Mite Treatment
Essential oils are used to promote good health in honey bee colonies. These oils have also been used in the quest for varroa mite control.
There are several essential oil recipes for bees that you can make and try in your hives. But, use care, some essential oils are absorbed through the skin. Wear gloves.
More importantly, you must check to ensure that the treatment plan you choose really works for your bees. This means more mite counts and a plan to do something else if needed.
Apiguard is a gel containing thymol. It acts as a fumigant to kill mites. Like most of the natural treatments, this products is temperature sensitive.
Temperatures should be between 59 F and below 105 F. Use twice at 2-week intervals to complete a mite control plan.
CONFUSION ALERT: There is a difference between Apivar and Api Life V A R. One is a synthetic chemical and one is a softer essential oil based treatment. Both are approved for use in beehives.
Api Life Var (thymol, eucalyptol oil, menthol, camphor) Api Life VAR is another contender for the best varroa mite treatment.
This product features a green spongy pad impregnated with oils. Api Life Var is a fumigant.
Treatment involves placement of pads 3 times at 7 day intervals. An acceptable temperature range is between 65-85 degrees F.
High temperatures during the treatment period can cause serious colony disruption including bees leaving the hive.
Organic Varroa Mite Treatments Options
Mite Away Quick Strips – formic acid (organic acid) works as a fumigant. The biodegradable treatment pads remain in place for 7 days.
After 7 days, you can remove the pads or not. You can use Mite Away Quick Strips when honey collection supers are on the hive.
Formic Acid also kills mites in capped brood (the others do not). This is an organic treatment but it is also strong – especially if the temperatures are very warm.
Some beekeepers have reported queen loss or a reduction in brood production. I never had any problems while using this product. Follow the directions on the label!
Extreme temperatures above 92 degrees F during the treatment application may cause colony absconding. In my region, the temperature requirements for some of these treatments were a big problem.
Formic Pro is another option for those wanting to use formic acid. This version has a longer expiration date for the package in case you want to keep some on hand. It works in the same way as MAQS with some of the same benefits and challenges.
I periodically use formic acid treatments in my colonies, they are very effective.
Oxalic Acid – Drizzle or Fumigant
Used in Europe for years, beekeepers in the United States can now use oxalic acid as a varroa mite treatment.
Oxalic acid (Oxalic acid dihydrate-organic acid) is used in two ways for mite control – as a drizzle or as a fumigant.
The drip or drizzle method involves mixing OA with sugar water and pouring this over the cluster of bees.
The drizzle method is best used in early Winter or late Fall. When the bees are clustered together the drip is easy to apply.
The colony should have little or no brood so the majority of mites will be on the adult bees.
The yearly limit of drizzle applications is 2 per year. This is because the acid is corrosive to bee bodies. Do not use drizzle treatments in extreme cold. The bee cluster can become chilled.
Vaporization of Oxalic Acid
Oxalic Acid Vaporization – This method of using OA is a favorite in Europe where it has been used with good results for years.
Here is how it works – a small amount of OA is place on a special wand and slid into the hive. The wand heats causing the crystals to vaporize.
As the vapor cools, crystals reform inside the hive. Honey bees remove the acid crystals and expose varroa to the substance.
Oxalic acid vaporization is a very effect varroa mite treatment during Fall and Winter – times when less brood is in the hive. It does not kill mites hidden inside the brood cell.
Be careful when purchasing a wand. You want one that works properly, you do NOT want to be inhaling any fumes. Wear appropriate safety mask etc. Follow the manufacturers directions – read the label.
There are many styles of oxalic acid vaporizers available for purchase. This is the model that I chose to buy – the Varrox .
I felt that it was the best investment because it has been in use for years in Europe. For fast cooling, this model is suitable for dipping in water. Cheaper models are not built to allow dipping in water.
Using OA in the Summer
Vaporization is my current method of mite control. I believe it is the best varroa mite treatment for bees in my area.
We have a lot of hot weather. Some of the other methods are just not suitable for treatment during July/August. This is the time that I need to have a healthy hive – getting ready to raise healthy Winter bees.
Because this method does not kill mites hidden inside the brood cell, the southern beekeepers I know – repeat this treatment every 5-7 days for 3 times. Thereby, covering a complete worker bee brood cycle.
Using OA Vaporization is compatible with the hot summer temperatures during my treatment window.
Fogging with Oxalic Acid- Should you?
You will hear a lot of information on the internet and Youtube about fogging with Oxalic Acid.
We humans are always looking for an easier way to do things. No harm in that -but you may harm yourself or your bees.
Fogging with OA is not approved in the US (at this time). I have not seen any approved research reports that say it is a good idea. I will not use this method for the present.
Varroa Mite Treatment Summary
In summary, the beekeeper is in charge of managing the bees. You may choose to do nothing and see if the bees survive. But, most colonies will not.
Is there one perfect way to kill mites without any chance of harm to the bees or contamination of beeswax? No, not yet.
Choose a mite treatment option and try it. If, the first one doesn’t work, try again. After treating, do another mite count. Don’t assume the treatment worked.
Maybe you would like to try treatment-free beekeeping. Okay, but find a reputable source for treatment free bees.
Try to go treatment free with regular main stream bees and you will have a lot of dead bees.
Are there other management strategies in use for varroa? Yes, absolutely. However, just because something may not kill your colony does not mean it has not caused harm.
Keep a log of what worked or didn’t work in your colonies each year. Good hive records can make beekeeping more enjoyable.
Record your beekeeping year in your beekeeping journal so you will have years of records on which type of varroa mite treatments you have used and the results.