August is a good time to be considering what treatment regimen you will use to battle Varroa Mites. So this week, I completed a survey of Varroa Mite treatments to help me determine what I want to use. Before we examine my survey of treatments, there are important updates from the bee yard that I want to share.
Hive Updates - More Surprises
Last week, I found lots of surprises in my bee yard. As if I hadn't had enough surprises, my bees decided I needed to experience a few more! But these surprises were not all unpleasant discoveries. So let's take a walk through the news from the apiary.
Just a month ago, I was worrying about the slow start this colony was experiencing. If you remember, I was concerned that Eleanor was not being a very productive queen. Eleanor is proving to be an exceptionally productive Italian queen. After a month of near stasis, this colony is now on a solid growth pattern.
A week ago, I placed a second brood box (a ten frame deep box). I also continued to feed these bees as I knew they had a lot of comb to draw on all those new frames. After just a week, they have a solid start on five of the frames. The workers have drawn pristine new comb on one frame. In that beautiful white comb, Eleanor laid eggs across the whole frame. Not one bit of pollen or honey, all eggs!
When all of these new bees emerge, there will be a general population explosion in Hive Acquitaine. My slow-starting colony has finally reached critical mass and is now putting on strength at just the right time. They had nearly drained the top hive feeder. I cleaned out the drowned bees to ready the colony for a refill.
This colony will likely need an additional medium box soon. I have one on order and it should arrive at just about the perfect time. Hive condos are rising daily! And if the nuc obtains a queen from their work, a fourth colony will be in the offing.
Hive Olympus - The Colony of Intrigue!
Ah, Hive Olympus! How fitting your name has become. Just as with the Greek Gods and Goddesses, Hive Olympus is an anthropomorphic honeybee battlefield.
Last week, I told you I feared that Hecate might have met an untimely demise. Well, this week I can confirm that the recombination of the two colonies did not go as planned. Apparently, one of the queens that emerged from the queen cups was in the hive, but I didn't find her. And, true to form, Hive Olympus did not disappoint with its palace intrigues.
I knew Hecate had met her demise when I found no eggs on frame after frame. Luckily, in the bottom brood box, I found the first eggs and larvae. And, I found the new queen.
The colony managed to raise a quite beautiful golden brown Italian queen, of some size. She escaped me before I could mark her and photograph her. Although I am sad for the loss of Hecate, I am quite excited that the colony raised their own queen. As well, she successfully completed her mating flights.
A small amount of eggs and early instage larvae were present on the frames. Rather than chance losing the queen, I chose to complete the inspections and close the hive up to give her more time to settle in.
Since she is a golden brown Italian, this queen cannot take the name of Hecate II. This queen becomes Athena. I will attempt to find and mark her next week.
Last week, I released the Italian queen, Beatrice II, into Hive Florence. She has settled in and has started laying eggs in empty cells. In addition to eggs, there were early instage larvae as well.
Searching through the frames, I found three more uncapped queen cups. I systematically destroyed the queen cups leaving this colony with only one option, Beatrice II.
For the second week in a row, the colony failed to completely drain the top hive feeder. They are significantly slowing their intake of the sugar water.
Additionally, they are beginning to draw comb on the honey super installed a few weeks ago. They have already filled the medium box with honey and hopefully will do the same in the honey super.
The colony has sufficient stores of pollen to provide for a quick growth to ensure once Beatrice begins regular laying in the brood boxes.
This small colony was filled with capped and uncapped queen cups last week. The queens in the capped cups from last week had emerged but none of them were present. However, there was another capped queen cup and a number of uncapped queen cups.
I am giving them another week to see if they can produce a mated queen. This little colony is very active with lots of foragers. You can tell that a lot of the workers in this colony were brood from Hecate's eggs as they have her dark brown markings like her.
Small Hive Beetles and Feeding
The Southern heat and humidity has brought small hive beetles to my colonies. Their appearance is not surprising and they are certainly not at any problematic levels. But, to be proactive, I am ordering small hive beetle traps for my colonies. Better safe than sorry dealing with the threat.
Before I departed for yet another week on the road for work, I went down to my hives and played bee whisperer again. I refilled the three top hive feeders without suit or smoker. It is incredible to interact with my bees this closely. I can hear their buzzing, clearly see their markings, and watch them drinking the sugar syrup.
Not one of the three colonies offered to attack or sting me as I refilled the top hive feeders. I also took time to place the entrance reducers back in place. This will assist the colonies as they fend off the inevitable robbing attempts from yellow jackets in the area.
Treatments for Varroa Mites
Varroa Mites have been the scourge of American beekeepers since at least 1987. Responsible beekeepers have an obligation to treat their colonies for these voracious creatures. Not treating opens up the colony to any number of viruses that may eventually kill the colony.
What's more your hives become a Varroa Mite vector for other beekeepers in your area. Granted, this is my opinion, but I believe that there are responsibilities when you take the care of a creature into your hands, even if that creature is a honeybee.
So for this week's blog post, I did a survey of the various available treatments for Varroa Mites in an attempt to help my own discovery process. For this survey, I examined the following treatment possibilities:
Each of these treatments has its pros and cons and some are effective while others are not.
With any treatment you are going to apply to your hives, you need to be aware of the instructions for delivery. Read those instructions and please follow them as it really does matter both for efficacy of treatment and safety for your bees.
For each treatment regimen, I will summarize the length of treatment, method of application, time of year to apply, restrictions on use, advantages of use, and disadvantages of use.
Apivar is an amitraz-based acaricide. It "does not kill mites directly, but is rather considered as a sub-lethal miticide with an original mode of action from neurotoxicity type, different from other current Varroacides. Acting on the synaptic transmission of mites, it leads to constant excitation and paralysis, followed by mite drop from the bee's back. Secondarily, Varroa dies due to starvation as a result of this paralysis. Amitraz acts by contact only."
It is applied by hanging one strip per every five frames of brood, which typically equates to two strips per hive. The strips are left in the hive between 44 and 56 days when bees are able to move freely throughout the hive.
It is not a treatment to apply during the winter cluster. It is also not suitable to use it during the honey flow. Studies have shown that Apivar kills 95% of the Varroa Mites in a colony with only one treatment.
If you treat with Apivar, you may place Supers on the hive two weeks after treatment removal. You should not use it more than two times per year.
It is important to rotate with other chemical controls. Apivar has a notable advantage in that it is safe and effective unless there is mite resistance. One of the chief disadvantages to this chemical is that low levels of break-down residue have been detected in beeswax and honey. There is also a chance for mites to develop resistance.
Api Life Var
Api Life Var "is a natural effective solution to control Varroa Mites infestation" using a combination of four natural products: thymol, eucalyptus oil, l-menthol, and camphor. The new formulation relies on a reduced dosage of thymol which reduces side effects from higher concentrations of thymol. "
The manufacturer provides studies that rate the efficacy of the treatment to a kill rate of 94%, with no mite resistence demonstrated.
The treatment requires you to break one wafer into four pieces and place on the corners of the brood nest. You repeat this process three times with one wafer every 7-10 days. This amounts to a 30 day treatment window but temperatures must be between 64 - 95° F.
Supers may be installed after treatment but cannot be harvested for 30 days post-treatment. As with Apivar, you should not use Api Life Var more than two times per year. You should also not use it when colonies are supered for honey. And it is important that you may not harvest the honey until 30 days following the removal of the strips.
One of the chief advantages of Api Life Var is that it is all naturally derived. But, it has some significant drawbacks as well. You absolutely must follow the temperature considerations. If the temperature is 80° F or above, it has caused bees to abscond from the hive. It also has been illustrated to cause greater irritability in the bees as well as tainting the taste of the honey.
Apistan is a pyrethroid based anti-miticide used in treating for Varroa Mites. It was one of the earliest treatments available for treating for these dreaded mites.
You may apply Apistan strips anytime when the bees are able to move about the hive as it is a contact-based treatment. But, you should not treat with it during the honey flow. Treatment consists of hanging two strips in the brood nest for 45 days.
The honey supers may be installed after treatment. There are pockets of resistance to the active ingredients, therefore, if you choose this treatment, you have to verify that it is working.
This treatment works best if daytime temperatures are greater than 50° F (10° C). Apistan is highly effective with susceptible mite populations, but significant mite resistance has been documented. It is a disadvantageous treatment because of the widespread mite resistance to it due to its overuse.
It also contaminates hive components, has a long half-life, leaves residues in the beeswax, and continued use of it may affect brood development.
Apistan also has quite negative synergistic interactions with other pesticides which can jeopardize the health of colonies.
CheckMite+ was one of the earliest treatments available to fight Varroa Mites. The active ingredient in this treatment is Coumaphos.
Delivery of the medication is normally done by hanging two strips in the middle of the brood nest for 42 days. It is effective any time the bees are able to move about the hive, but should not be applied during the honey flow.
CheckMite+ cannot be used when supers are installed and supers cannot be installed for 2 weeks after the treatment. You should also not use it in queen-rearing colonies.
CheckMite+ is effective and easy to use when the mite population is susceptible, but there is extensive mite resistant populations throughout the United States. This organophosphate may contaminate hive components, has a long half-life, has negative interactions with other products, and negatively affects reproductive health of queens (rearing) and drones (sperm production).
It is still effective in controlling small hive beetles. To use it to treat small hive beetles, cut 1 strip in half and attach it to a 5" X 5" corrugated square.
MiteAway Quick Strips
MiteAway Quick Strips are an all natural treatment for Varroa Mites that have proven to be quite efficacious, with a 90-99% kill rate including mites under the capped brood.
The active ingredient in MiteAway Quick Strips is formic acid. The formic acid molecules are fanned into the brood and are small enough to permeate the caps of the capped brood and kill the mites sheltering with the developing pupae.
The treatment requires application of two strips near the edges of the bottom-most brood box. Treatment consists of a 7 day application while daytime temperatures are between 50 and 92° F.
Unlike many of the other treatments, MiteAway Quick Strips may be applied with honey supers on the hives and the strips are compostable.
One critical requirement with MiteAway is to observe very strictly the temperature requirements when you are applying these strips. In fact, excessive temperatures above 92° F (33° C) have been known to cause brood mortality and even bee absconding.
The chief advantage to MiteAway Quick Strips is that it is an entirely natural product that you may use while bees are actively storing honey in honey supers. It also is able to kill mites under the brood cappings.
There are some disadvantages to using MiteAway. Some beekeepers have reported brood mortality while others have indicated total queen loss after using this product.
A relative newcomer to Varroa Mite treatment, Oxalic Acid has many proponents for its use. It has proven to be quite efficacious at cleansing adult bees of mites.
There are three approved methods of delivery for Oxalic Acid:
- Creating a liquid solution with the Oxalic Acid and dribbling it over the brood box and bees,
- Heating the Oxalic Acid with a vaporizer and spreading the fumigant throughout the hive, and
- Spraying packaged bees.
By far the most common delivery method is using a vaporizer. You may purchase a vaporizer here.
Oxalic Acid treatments are most effective in the winter and during periods with no brood present. This treatment may be used to effectively cleanse adult bees of mites during broodless periods. But, it is very corrosive and came damage your bees if overused. Additionally, the liquid application may chill the adult cluster.
HopGuard II is another organic, naturally occurring treatment that is new on the market. It is a miticide derived from natural hop compounds.
My craft beer-making co-workers who want me to make mead found it fascinating when I told them there was at least one miticide made from Hops. Hopguard is suggested to be used during periods when either brood is not present or brood is reduced.
Treatment consists of one strip per every 5 frames of bees over a 4 week period. Its maximum use is suggested to be three times per year for a total of 6 strips).
Hopguard may be used during honey storage periods. It is currently not legal in all states in the United States and requires Section 18 registration for use. You should check with your State Department of Agriculture to see if it is approved in your state.
Its two primary advantages are that is a naturally occurring compound, not a hard chemical treatment, so it can be used during honey storage periods.
There are some significant disadvantages to its use. The strips used for treatment are "messy" to use and you should wear disposable gloves when working with this product. You also should check its effectiveness at mite control following treatment.
There have been varied reports on its efficacy to date and this particular formulation is the second different formulation in two years. If you use it and notice adverse effects, you should immediately report these to your State Department of Agriculture as that information will be shared nationwide and is of benefit to your fellow beekeepers.
Apiguard is a "slow release gel that ensures correct dosage of its active ingredient thymol. Thymol is a naturally occurring substance derived from the plant, thyme."
The treatment comes in 50g ready-to-use aluminum trays, with two trays being enough to treat one standard colony. There are 25g sachet's available for use with nucs. Average efficacy runa around 93% with control levels often being higher than that.
It consists of two treatments. The first treatment runs from 12 to 14 days followed by a second treatment that runs from 2 to 4 weeks in length. Place the delivery tray on top of the top bar frames or atop the brood frames. You'll need a 1/4 inch space between your boxes so you'll need to purchase a shim. You will also need to close off screened bottoms and vent holes.
Apiguard should be applied during the fall, unless your Varroa Mite infestation is severe. Outdoor temperatures must be monitored as it should only be applied when temperatures are running between 60° F and 105° F. You should also not apply this treatment when honey supers are on the hive.
The chief advantages to Apiguard are that it is a naturally derived compound and is easy to use with container or tub. However, there are some drawbacks to using it.
Apiguard may reduce queen egg-laying activity. It also may increase adult and young larvae mortality rates. It also works best under warmer temperatures.
Apiguard also has been shown to cause bees to beard in hot weather. You should also wear protective gloves when working with this agent as it is a human skin irritant. This treatment modality has not been approved for use everywhere yet.
If you want an exceptional tool for helping you grasp all the tools for Varroa Management, you should definitely be checking out the web page for the Honey Bee Health Coalition. They also have an exceptional guide, Tools for Varroa Management: A Guide to Effective Varroa Sampling & Control.
Additionally, there are a number of articles on PerfectBee concerning Varroa Management including:
- An Overview of the Main Threats to Bees
- Monitoring Varroa Mite Levels
- The Threat of Varroa Mites: Part 1
- The Threat of Varroa Mites: Part 2
- Obtaining and assessing varroa mite count
Coming Next Week
Next week, I will tell you what my final decision was concerning treatment for Varroa Mites. This coming weekend our beekeepers club is meeting with the state inspector and other master beekeepers to talk about treatment options and actually inspect hives looking for tell-tale signs of Varroa Mite infestation.
I am looking forward to learning from some master beekeepers. I will also give you more updates on the progress of the new queens.
Until next time, happy beekeeping!