Varroa Mite IPM: Q&A


Kim Skyrm

Kim Skyrm, Apiary Program Coordinator/Apiarist, Massachusetts Department of Agricultural Resources

Jennifer Lund

Jen Lund, Apiarist, Maine Department of Agriculture, Conservation and Forestry

They’re back by popular demand! Kim and Jen dive deeper into managing the most detrimental pest affecting honey bees, varroa mites (Varroa destructor). These questions were asked and answered during the four-part webinar series Varroa Mite IPM. We’ve categorized the questions into seven topics:



Q. Do you test for mites on a dead-out with an alcohol wash?

A. We will go over this in future webinars and provide you with a few different options. It is always great to see not only a good estimate for the amount of mites on the remaining bees and also a great way for you to get more experience doing these washes—practice makes perfect! :)

Q. I got ahold of one of the CO2 monitoring devices. Is there any efficacy info, compared to alcohol or sugar shakes?

A. We did a quick literature search and could not find any relevant studies. You could try both methods on your hives and compare the results.

Q. Is there any research on accuracy between sugar roll versus alcohol wash specifically?

A. There have been several comparisons over the years (web search: sugar roll vs. alcohol roll varroa mite) and both are comparable if done correctly. For most beekeepers alcohol rolls will be the better option for monitoring because that method is easier and less prone to error.

Q. I'm a second-year beekeeper. They've made it through the winter, but when we realized we had a varroa mite problem and treated, there were too few bees to do an alcohol test. What are testing strategies with low bee populations, or should you just treat and not worry about a pre/post test?

A. If there is a small population and you know there is a mite problem, you should treat. If the population grows test the mite level after treatment.

Q. What would you use to treat a new package of bees upon install if needed?

A. There are a lot of options. What you use depends on the temperatures at install and its potential impact on the newly installed queen.

Q. I just installed a package and there must be 100 mites in the bottom of the box. Should I treat now—and with what—for a new package?

A. You should test to see what the living mite levels are on the living bees and see if you need to treat. Some suppliers treat packages before shipping and those dead mites could be a result of a successful treatment before you received the package.

Q. How successful is using a drone frame to reduce mite numbers?

A. Drone brood frame alone is not adequate to manage for varroa mites—you definitely need an IPM plan. We talk about how to make an IPM Plan in Part 4.

Q. For the alcohol wash... what about windshield washer fluid (-40 C rated) instead of lab grade 70% isopropyl alcohol?

A. Yes, windshield washer fluid will work.

Q. What's the best treatment for the wild temperature swings in northern Maine?

A. In far northern Maine, we rarely see temperatures that are too high for long stretches (there may be up to a week toward the end of the summer above 85F) so most treatments are able to be safely applied. The one thing to watch out for is low temperature (day) thresholds. Some miticides do not work well if the day temperature is below 55F.

Q. When you are talking about temperature range, is it night or day temperature?

A. Day temperature.

Q. What is the lowest amount of mites seen that should be treated?

A. 2–3% mite infestation is the currently recognized threshold, depending on where you are in your hive colony growth. Check out the Honey Bee Health Coalition Guide for Varroa Management for more details. (

Q. Our local association has been having a debate between shaking vigorously or just swirling during the alcohol wash. Any thoughts on which is more effective?

A. Shaking is how all the pros (the bee research labs) do it!

Q. If you have an apiary with say 5 to 6 hives and one hive has 0 to 1 mite in 100 bees, can you NOT treat that hive? If we keep treating all the hives, are we not finding the hives that can deal with a few varroa over the season?

A. One of the great things about monitoring is that you can find those hives that are better at dealing with varroa. If you are below threshold you do not need to treat that hive and if it stays that was consistently, it is one you can use to make queens from with the hopes that that genetic line is more “resistant” than your other hives.

Q. Is it to early to apply a treatment in Hampden County?

A. It depends on what you use. Some products have no temperature restrictions and can be used this time of year. Kim will be discussing the different options in a little bit and will be mentioning some options that could work this time of year.

Q. Is doing multiple oxalic acid treatments a few days apart an effective way of killing a high percentage of the mites in a colony?

A. Read and follow the label carefully ( There is not a restriction on how often you can apply OAV but there are restrictions on when you should be applying it: when there is little or no brood, packages, or swarms. The current research shows that it does not matter how often you treat with OAV, if you have brood in the hive it is not effective. This is because the vast majority of the mites are found in cells under cappings (50–80%) and the OAV does not kill them. It has no long lasting effectiveness in the hive (kills mites for 10–20 minutes when it is in its vapor form) so 30 minutes after a treatment, mites are emerging from cells and replacing those you killed with the treatment.

Q. Is doing multiple oxalic acid treatments a few days apart an effective way of killing a high percentage of the mites in a colony?

A. There is not a restriction on how often you can apply OAV but there are restrictions on when you should be applying it: when there is little or no brood, packages, or swarms. The current research shows that it does not matter how often you treat with OAV, if you have brood in the hive it is not effective. This is because the vast majority of the mites are found in cells under cappings (50–80%) and the OAV does not kill them.

Q. How does one cage a queen?

A. It's a bit hard to explain how to do it with out seeing it in action. There are many different ways to capture and cage a queen as well as many different types of cages one could use. Search “how to cage a queen video” and watch a couple of the videos you find there.

Q. How long does an oxalic acid/sugar syrup mixture last if refrigerated?

A. It is recommended that you use an oxalic acid/syrup solution shortly after you prepare it. Its shelf/refrigerator stability after being mixed is not very long.

Q. Do I need to wait for open uncapped brood in order to do a proper alcohol wash?

A. One trick I use: When you find a frame that you want to use for an alcohol roll, look very carefully for the queen on it. If there are a lot of bees you can shake half of them off into the hive and then look again at the frame with less bees on it. Usually if you shake a frame and the queen is on it she will fall off and with less bees you should be able to see her more easily if she hangs on.



Q. Question for Jen... do you have a date in mind when you plan to do your first mite count in Maine?

A. I usually tell beekeepers to perform their first mite roll during your first full spring inspection. Usually late April (if we are warm) but most likely May.

Q. When do you recommend the first preventive treatment after winter?

A. We instruct beekeepers to do an alcohol wash during the first month of active bee season—i.e., when you see bees flying in and out daily. Use this number to judge when to think about treatments. We recommend that you perform these alcohol washes monthly during the active bee season. We will talk more about how to best time your treatments in future webinars, so stay tuned.

Q. I lost a hive this past winter and unsure of the cause but believe it to be mite related as there were dead mites present in the hive, and there were food stores left. I will be getting new hives this spring but when do you recommend a mite check/treatment for a new nuc?

A. At install or shortly afterward. I also suggest asking the person who you bought it from what they have done to control mites, or if they have sampled for mite recently.

Q. When should we treat for mites?

A. I recommend that you do an alcohol wash to monitor for mites at least 1x per month during the bee season of activity and treat as needed—if the mite wash threshold from the count is reached (i.e. you get more than 3–9 mites in the wash results), treat. We will talk more about how to create an IPM plan in Part 4.

Q. When should we treat coming out of winter? March or April?

A. Definitely consider doing an alcohol wash after the first brood cycle of the new bee activity season AFTER the first frost or when temps are consistently during daytime/night above 55/60F—i.e. when bees are able to fly out of hive daily for the first month after winter. If you have an overwintered hive coming out of winter. Do an alcohol wash first then use it as a guide on how to best select a treatment. We will talk in greater detail about treatment options and management plans in future webinars so stay tuned! :)

Q. If I have overwintered my hives then do I need to treat now?

A. You should perform an alcohol roll to determine if you need to treat.

Q. You mentioned needing to treat at end of June–July. What kind of treatment can be done, especially considering there might still be supers on the hive? You noted that waiting until August is too late.

A. If there is honey still in the hive and you need to treat for mites, you could use HopGuard or one of the formic acid miticides. Both are labeled for use while bees are producing honey. With the formic acid products you have to be careful with high temperatures.

Q. How soon after treatment should you do the post treatment wash?

A. As soon as the treatment is completed (i.e., removing the strips/tins/pad from the hive) you can test.

Q. On the threshold number—we have been hearing in DC/MD that the threshold is 3 (not 3–9) and some say if you see one you should treat, because likely you’ve got more.

A. It’s a range... any more than 3 requires a treatment.

Q. How long after treatment should the mite count be done?

A. It’s easiest to resample as you are removing the treatment from the hive.

Q. When should you test new packages of bees that come from the south?

A. At install.

Q. Can you please comment about how soon a new hive from a package needs treatment? I plan on starting monthly alcohol wash monitoring about a month after install. It’s been too cold a spring so far to open them up or adhere to treatment labels.

A. You should perform an alcohol wash to see if you need to apply a miticide.

Q. I was told by my dealer to treat even though he said they have been treated already. He said he always does... do you agree?

A. I always recommend doing a mite wash at install. It is good practice, you know where you queen is, and you may not have to treat (some of the treatments can be hard on the bees and expensive).

Q. I have installed several packages from the same supplier. Do I need to do an alcohol roll on each hive now, or can I assume if one hive is above the threshold the other would be too?

A. We find a lot of variability in mite level between packages so if you can sample each of them, that will make sure you don’t miss a problem. If you installed a lot of packages (10+) you can do a subsample. As an example, I installed two packages last year and one rolled a 1 and one rolled a 9.

Q. What would you do with weak hive? One of mine lost the queen over the winter. What would you have done?

A. There is not much you can do about losing a queen during the winter. If you have a weak hive now, you should figure out why it is struggling (disease, failing queen, etc.) You should reduce it to the smallest sized box you can (I deep or a nuc) and give it some brood and nurse bees from another hive to boost it. If it has no queen, you can see about purchasing one or combine it with another hive.

Q. Just wanted to clarify... you recommend a varroa mite roll/check when hiving a new package?

A. Yes.

Q. Is this a good time to apply Oxalic Acid fumigation? I have one existing hive that made it through the winter. Also, I am taking a split from a friend. Should I fumigate those as I add to new deep?

A. Read and follow the label carefully ( There is not a restriction on how often you can apply OAV but there are restrictions on when you should be applying it: when there is little or no brood, packages, or swarms. The current research shows that it does not matter how often you treat with OAV, if you have brood in the hive it is not effective. This is because the vast majority of the mites are found in cells under cappings (50–80%) and the OAV does not kill them. You should monitor using an alcohol roll to determine if and when you need to treat.



Q. Are there other visual cues that identify if you have varroa mites present?

A. There are a lot of different visual clues you can see in the hive that will tell you that you have varroa mites. Unfortunately, most of them are only apparent when you have a severe infestation as the hive is collapsing. Signs: mite poop on the walls of the cells, holes in the cappings, deformed adult bees, aborted/chewed pupae and larvae, etc.

Q. Can the fat body of winter bees be significantly reduced in size/mass by varroa mites?

A. Yes.

Q. Is there a connection between varroa mite levels stressing bees and triggering small hive beetle laying?

A. If bees are stressed from high levels of varroa mites, they definitely would have a more difficult time managing SHB infestations. I have not seen any specific scientific literature comparing these two stressors. Hope this helps.

Q. In the differential diagnosis between dead-out from varroa mites and dead-out from pesticides, can we assume varroa because it’s most common?

A. The way to tell the difference is by looking for the symptoms of varroa mites or a pesticide exposure in the hive as your are inspecting the dead-out. Here is a fact sheet on how to perform a hive autopsy:

Q. Does the virus serve a purpose to the mites, like aiding in digestion?

A. Not that we know of, it seems to be only a vector.

Q. Do you ever recommend mite treatment prophylactically?

A. I always recommend treatments based on alcohol roll. The only exception is for a late season (Nov/Dec) cleanup treatment using OAV. In that case, it is usually too cold to perform a wash.

Q. Male mites—are they a different size or color than females?

A. Yes, the male mites are smaller and cream colored. See some pictures here

Q. Has there been any new studies on mites and their biology and possibly controlling them or eliminating them?

A. Yes, there is constantly new research being done on controlling varroa mites.

Q. Is there a mite predator?

A. There is a pseudo-scorpion that does kill mites. Unfortunately any predator needs to be tolerated by the bees, on the bees, or on the comb because that is where the mites (their prey) are located. Bees typically do not tolerate them in the hive.

Q. Any developments on biocontrol agents for control of varroa mites?

A. Researchers are always looking at potential biological controls. They have identified several organisms that kill mites effectively in the lab and are safe for bees over the years. Unfortunately once they are tested in the hives, they don’t work well. A good example is a fungal pathogen (Metarhizium anisopliae) that was developed several years ago. In the lab it kills the mites and is safe for bees. In the hive it doesn’t work well because it requires a cool temperature and moist environment to germinate properly. Unfortunately, hives are hot and dry.

Q. You touched on this in the last webinar, but to clarify: how long after a hive dies will the varroa mite survive? When performing a hive autopsy is an alcohol wash effective or should another method be used to get the percentage?

A. Roger! The varroa mites die shortly after the hive dies. Yes, alcohol roll on the dead bees will give you a percentage.

Q. Why not just assume you have mites?

A. You probably do have mites. The key is to understand what those levels are in order to make decisions on treatment timing. You don’t want to treat unnecessarily (some treatments are expensive and/or can damage the brood and queens). You also don’t want to treat too late because once the viruses get a hold, your hive is likely not going to survive.

Q. Why is colony death never attributed to tracheal mite infestations any longer? Yet there is no research so far that states that genetics have taken care of tracheal mites?

A. Tracheal mites are also killed when we treat for varroa mites, so that is giving a lot of beekeepers coverage. Often when we have an “unexplained” death it is something that we check for, but rarely see it.

Q. When removing drone brood, how do I dispose of wax with mites?

A. You can put the frame in the freezer, it will kill the mites. Then you can install the frame back into the hive and the bees will clean out the dead brood and mites.

Q. Do mites totally die off in the winter?

A. The mites do not die during the winter. They live between the abdominal segments underneath the adult bees during that time feeding on the fat bodies of the bees.

Q. Could you give an approximate date for mite peak population?

A. It is difficult to come up with a single date. Mites will peak at different times in different hives depending on hive growth, outside food resources, swarming, etc.

Q. Buckfast bees? Resistant to varroa mites? Other breeds?

A. There are some varieties of bees that exhibit some level of “resistance” to varroa mites. We went over some of them in Part 3 and 4. Using those varieties are a good foundation to successfully controlling varroa mites. They are the bottom level of varroa mite IPM



Q. As part of an IPM strategy, has anyone in the beekeeping industry analyzed the natural mite drop per colony with correlative analysis to infestation rate, and is there any way of snapping a picture and utilize software to count mites in the picture and provide a simple quantitative result for infestation and treatment recommendations?

A. Unfortunately there is a lot of factors that affect natural mite drop (honey flows, bad weather, bee population in the hive, grooming behavior) so it is always hard to correlate drops with infestation rates. Many researchers over the years have tried to develop software to estimate populations using photographs with limited success.

Q. Do you try to use a mix of treatments so bees don’t build up a resistance?

A. Yes, miticide rotation is very important to reduce the likelihood of building up resistance in the mite population.

Q. With amitraz resistance now found in both the USA and Canada, is the resistance more prevalent in Apivar treatments versus other methods of applications? And do hives that exhibit amitraz resistance express viruses as much as would be found in an untreated hive?

A. If you have high mite loads in a hive, you most likely will also see high viral loads. They go hand in hand. When investigated, most of the claims of resistance to amitraz do not appear to actually be resistance (using the standard Pettis test for resistance) but failed applications. When Apivar is used properly, it still gives good control.

Q. I noticed in your Mite Treatment Guide, you had x’d off Apistan and Checkmite. Does this mean you no longer recommend using these products?

A. Varroa mites have shown wide spread resistance to both of those miticides.

Q. With the existence of mite resistance being a reality in North America, has the resistance been tied to the product Apivar, or shall we be politically correct and ask if the “other” method that has blue as an identifier as that type of method. Is one method or the other seen as a treatment that is contributing to amitraz resistance?

A. When investigated, most of the claims of resistance to amitraz do not appear to actually be resistance (using the standard Pettis test for resistance) but failed applications. When the approved method of treating using amitraz (Apivar) is used properly, it still gives good control.

Q. Do herbs like thyme help?

A. There are no scientific data to show that herbs help in their natural form. There are some miticide treatments that have similar properties as the thyme plant—and we will go over these in future webinars. Stay tuned! :)

Q. Is there any plant-based or botanical formulations to manage varroa mites?

A. Both of the thymol and the one HopGuard miticides have active ingredients that are originally found in plants (thyme and hops).

Q. Are there any areas in the world where honey bees are developing resistance to varroa mites? Apis cerana—original varroa mite host has a really neat way to control varroa mites: Wondering if we can genetically engineer the resistance into honey bees?

A. Not anytime soon. To register a genetically modified animal takes years (decades) of development and research to determine it will not have any ill effect on ecosystems.

Q. Any update or opinion on oxalis shop towel treatment? We applied #1 on July 1 and #2 late August with less than 1% the entire year.

A. This is not an approved method of treating for varroa mites.

Q. Oxalic acid is legal in the U.S. Obama legalized it when he was president because Michelle had bees kept at the White House. It was their specific use of oxalic acid, the method they were asking about, which was not a legal use.

A. You are correct; the methods or application are limited to the three methods described by the oxalic acid pesticide label. Fogging is not an approved method.

Q. Is fogging the same as using an oxalic acid vaporizer?

A. No, fogging is different than using a vaporizer. With fogging the oxalic acid is mixed with alcohol or oil.

Q. Is it true that oxalic acid only treats for 3–4 days? Would it be safe to treat with oxalic acid every 4 days for 24 days? Benefits? Draw backs?

A. Read and follow the label carefully ( There is not a restriction on how often you can apply OAV but there are restrictions on when you should be applying it: when there is little or no brood, packages, or swarms. The current research shows that it does not matter how often you treat with OAV, if you have brood in the hive it is not effective. This is because the vast majority of the mites are found in cells under cappings (50–80%) and the OAV does not kill them. You should monitor using an alcohol roll to determine if and when you need to treat.

Q. Is wood bleach okay to use for oxalic acid?

A. No, it is not approved for use in bee hives.

Q. Is the oxalic acid that you would buy the same as the oxalic acid that says “deck crystals—metal cleaning 99.6%”?

A. No, you want to get oxalic acid that is specifically labeled for treating mites on bees. You can find it online from various bee suppliers. You do not want to use anything you get at a hardware store—those products are not labeled for use in hives, so it is illegal to use them in that way. Also there are other things in those products besides oxalic acid that could kill your bees or harm you.

Q. Use of organic acids like formic acid or oxalic acid is common in India for varroa management. What are the ill effects of these organic acids to bees or pupal brood if applied over dose?

A. Formic acid can kill open brood and the queen, especially if applied over dose and when temperatures are too high.

Q. Does acetic acid fumigation (as for Nosema) help reduce virus counts in frames from dead-outs?

A. We do not know the answer to this. There is a lot of research currently being done on the longevity of virus on comb after a hive dies.

Q. On your schedule of treatments, you’re using Api Life Var in May with honey supers on?

A. They use Api Life Var if the supers are not on.

Q. Should Apivar and OAV be used at the same time?

A. We do not know if applying multiple miticides in the same hive has detrimental effects on the bees. I would caution doing it.

Q. Considering negative impact on queen development and drone sperm by miticide residues within the hive, are some classes of miticides worse than others? Do synthetic pyrethroids (fluvalinate and flumethrin) and Amadines (Apivar) have more impact than organic acids and/or essential oils? And are synthetic (chemical) miticides more persistent in wax? If these are true, should one tend to reserve the use of synthetic (chemical) miticides until after queen-rearing/swarming-season (after harvest) and use “softer” miticides in the spring?

A. All currently registered miticides have been found in the wax of hives. The way to mitigate the effects of these buildups is to rotate out your comb on a 3–5 year cycle.

Q. Do any of the miticides affect the microbiome in the bee gut?

A. I am not aware of any studies that found this to be the case, but there is a lot of new research being done (in the past two years) looking at the gut microbes of bees, so I wouldn’t be surprised if someone is looking at it.

Q. When will this RNA treatment for mites get on the shelves?

A. There have been some hiccups with the research, but they are still working on it. No idea what their timeline for release is.

Q. If I want to use OAV for mite treatment, is it best to do five treatments five days apart, or is there another method?

A. Read and follow the label carefully ( There is not a restriction on how often you can apply OAV but there are restrictions on when you should be applying it: when there is little or no brood, packages, or swarms.

Q. If I keep my yard organic, does applying this pesticide negate that?

A. There are varroa mite treatments that are OMRI (organic) certified including the two formic acid products.

Q. I had two hives in Huntington, NY. Survived one winter. Last nectar flow season the queens in both hives died, or somehow disappeared (almost at the same time, maybe a few days apart). Both hives had eggs and capped brood at the time the queens died, and they raised new queens and the hives got back on track. After a few weeks, the queens were again replaced naturally by the hives (not sure why, as both queens were laying eggs and looked healthy). In the fall we had stable hives with queens, brood and eggs. We got Formic Pro to treat the hives, but chose not to do the treatment because one of the warnings on the information sheet that came with the Formic Pro was that the queen may die during the treatment. Did not notice many varroa mites in the fall and chose not to do the treatment. As a result, both hives died in the winter because of the mites, of course! The hives had most of the honey left in the hives... How likely is it that the queen would die during treatment with Formic Pro?

A. The risk to the queen is reduced if you follow the instructions on the label carefully (especially temperature restrictions). If it is too hot when you do the treatment, you are more likely to lose your queen. Also if you treat one pad 10 days, followed by one pad 10 days (one of the two approved methods) you will have less impact on the queens.

Q. Kim, how can we check to see if a product is registered for use in my state?

A. Kelly Registration System or NPIRS

Q. I used HopGuard II a couple of years ago and it did not seem to work well. What do you think of its efficacy?

A. HopGuard works best when there is little or no brood in the hive and when you follow the label specifically.

Q. Are you aware of any more research on the use of lithium as a treatment?

A. There was some initial research that showed some positive results using lithium chloride, but follow up studies did not support those first results. I think there are still one or two labs still working on it.



Q. If the queen is infected with a virus, will that virus be transferred to the eggs she is laying? How would you know if that’s happening?

A. Yes, this can definitely occur with some viruses—depending on the virus type. Traditionally, folks have recommended re-queening as a method for viral control, but this is not always effective. Most likely it will not hurt, but does not guarantee viral elimination.

Q. Has there been any research conducted on adult bee survival once a mite has begun feeding? After treatments, assuming mites are killed, there will be bees that have had their exoskeleton punctured. Will that wound site heal and the bee survive?

A. Most bees do not recover well once they are fed on by the varroa mite. Besides the hole the feeding makes, the varroa mite can introduce viruses and bacteria that further sicken the bees. Also varroa parasitism is associated with decreased lipid synthesis, reduced protein titers, desiccation, impaired metabolic function, inability to replace lost protein, precocious foraging, heightened winter mortality, impaired immune function, decreased longevity, and reduced pesticide tolerance. A great paper on mite feeding can be found here:

Q. Is there a federal agency that is working on the varroa problem?

A. The problem of varroa is being worked on by several entities at the state, federal, university, not for profit, and private industry level. It has everyone’s attention.

Q. If you do the acid wash, how long will it take IF the tracheal mite were to grow into a problem?

A. I’m going to assume you are referring to an oxalic acid treatment. We are not sure. In the example I gave, the transition to OAV happened over a couple of years, but it really depends on the level of tracheal mite already present in your hives and in those that you introduce into your apiaries (in the form of packages and nucs).



Q. Are there any clear signs/symptoms that equipment (frames specifically) should NOT be reused year to year? It is tough to let go of established drawn comb but if the frames have previous mites or disease, is it better to burn/let it go?

A. The rule of thumb is to replace comb on a 3–5 year cycle. You want to remove about two per box per year which would give you a rotation of all frames over five years. Focus on replacing those that are very dark and have small cells or totally waxed over.

Q. When using a drone frame, I remove them at the appropriate time and freeze them. How do I then reuse those frames full of dead drone brood (and dead varroa mites)? Put them back into a hive and let the bees clean them out?

A. You can also use a hose (or chickens) to clean out drone frames, although that can damage the drawn comb...

Q. Do you feed green frames to chickens and not freeze them, or chickens first and then freezer?

A. Usually once the chickens are done, there is no need for freezing!

Q. I don’t like to take insulation off my existing hives before frost is certain, and I have a new package arriving to replace one that died. In the interest of keeping everyone healthy, I want to treat. Don’t want to do oxalic acid since it won’t get to new brood... what do you recommend?

A. Apivar and HopGuard don’t have any temperature restrictions.

Q. With a Warre hive, without sidebars on the frames, can you still use the wash basin the same way?

A. Yes. Instead of tapping the frame in the bottom, gently shake the bees off into the pan.

Q. Another Warre question, is there a key times to check for varroa mites? The philosophy is to avoid opening the hive.

A. At first full hive inspection and then monthly after that.

Q. Given that we are still experiencing cold snaps at night, I have not taken off my insulation. I also don’t want to take apart the hives because it disrupts the propolis they’ve built to stay warm. So, should I, in the interest of discovering my mite count, take them apart on the next warm day? It’s a trade off... what’s the answer?

A. Messing with hives in the cold only hurts them, never helps them. Leave it till it’s warm.

Q. I know that you have to remove honey supers before doing an OAV. How long do I need to wait before placing supers back on hive?

A. As soon as the vapor recrystallizes it is safe to put back on the honey supers. Usually keeping the honey supers off for 30 minutes following treatment is sufficient.

Q. Can you rotate supers and drawn comb that has been extracted, or should you keep to each specific hive?

A. You can move frames/boxes between hives. Just be careful that what you are moving is healthy. You do not want to move a diseased frame to an otherwise healthy hive and make that one sick.

Q. It seemed like Jen and Kim gave opposite answers to whether or not you can consume the honey in the spring after treating with OA in the fall?

A. The first question was whether it was safe for the frames to be reused the following year for honey supers after the bees have eaten all the honey. That is safe. The second question was whether it was safe for humans to eat honey from OAV treated frames. That is not allowed by the label.

Q. When we get to the appropriate time, what treatments, if any, can we use with honey supers on? If none, is there a practical way to store them while treating and then put them back on?

A. HopGuard, Formic Pro, and Mite Away Quick Strips can be used with honey supers on.

Q. What is your opinion of the Mighty Mite heaters that say they can kill mites inside capped brood by heating to 106 degrees?

A. There has been some research on heating the hive to kill mites but not kill bees. The results have been varied but it can be one of the strategies used in your IPM tool belt.

Q. If you freeze a drone frame, then place it back in the hive, will at least the effort to create and cap the drone cells be recovered? Will they vacate the frozen drones/mites and reuse, taking up less resources?

A. Yes, the bees will remove the dead drones and refill with new brood. It does take some work for the bees to uncap and remove the dead drones but they will reuse the frame.

Q. Are the bees less likely to draw out drone brood on the bottoms of frames if you are using a drone frame?

A. It would be nice if the bees took our “hint” when we gave them the drone frames, but often they don’t and will still produce burr comb between and beneath the frames in the hive.

Q. What is a rim spacer?

A. It is also called a “shim” (web search: bee hive shim for some pictures). It is a 1–2 inch rim that you put on top of the top hive body to give a little extra space. Sometimes also called a feeding rim.

Q. I’ve seen a lot of these labels referring to deep frames. For those of us running all mediums, how can we adjust to account?

A. Typically we say 3 medium boxes is equivalent to 2 deeps.

Q. Would using a blow torch to sanitize used equipment be effective?

A. Boxes yes, frames not really.



Q. Not a question, but a possible suggestion. I worry more about moisture than cold over winter. This year I used Vivaldi tops with wood shavings and, for the first time in 3 years, haven’t lost a hive as of yesterday!

A. That is awesome! Congrats! :) We are hearing reports of hives having an overall successful winter for a lot of beekeepers, including “new-bees” so we are EXCITED to continue to hear about folks with live hives coming out of the winter!! :) Moisture can be a tough problem during winter, especially in climates that have a change in seasons (i.e., actual cool winter weather compared to just a few days of milder temperatures). Great to know that you have had success with these boards! :)

Q. How can I set up an appointment to inspect my hives? One is doing great, the other is dead and gone and the hive stinks.

A. Reach out to your local apiary inspector. Find them here:

Q. Really hard connecting with a mentor in these COVID times... I am in southern Maine. Bees due on the 1st.

A. Try reaching out to your local club and see if there is someone who lives close that can help you with your hives. Good luck with your new bees!

Q. I really need a hive inspection. How do I arrange for it, who do I contact, and how long does it usually take from the request till the actual inspection?

A. You can contact your state inspector if you have one. You can find your inspector here: One thing to note is that many states have halted inspections to help slow the spread of COVID-19

Q. How close together are these hives you have tested. The reason I ask is that mites are not my biggest problem because my hives are about 20' apart and I plant thyme and mint in front of my hives.

A. Apiary design is very variable. Some beekeepers have hives only a few inches apart, others very far apart.

Q. What is the recommendations for spacing hives to reduce drift and or mite levels? I have mine a minimum of 10 ft away from each other in order to reduce drift.

A. Spacing 10 or more feet apart can help reduce drifting. Also keeping entrances small to half open and facing entrances in different directions can also help.

Q. What about the dead fish or rotten meat smell?

A. Bad smell is usually a symptom of one of the foulbrood. If you have unusual smells coming from your hives, reach out to your apiary inspector to get them tested.

Q. I have three hives and one died from mites, but the other two seem fine so far. If bees will go to other hives, why didn’t they go to other hives and expose them?

A. There are many factors that can affect mite populations and drift between hives.

Q. I have a question. So can a selective chalkbrood be created that would activate only if the pupa has a varroa developing?

A. Chalkbrood typically develops in a hive under very specific conditions. The brood during a 3-day period becomes chilled and moist. I’m not sure developing a strain that would activate in the presence of mites would be possible.

Q. Are people rendering the wax or freezing?

A. I’m not sure I understand this question. Some beekeepers store their wax scraping/cappings in the freezer before they render it so wax moth and other pests do not get into it.

Q. Have you seen the bee gym and if so what is your opinion on its use to reduce varroa mites via mechanical means?

A. Most of the strategies that have been developed to physically remove mites from bees do not work well enough to totally control the mites but can be used as one of the tools in your IPM tool belt.

Q. Are people rendering/disposing of affected comb, or freezing and reusing because of the inherent value of drawn comb?

A. It depends on what it is infected with. For AFB, it is to be disposed of. For all other maladies, it can be cleaned and reused.

Q. Please talk about harvesting honey from dead-outs.

A. If you used a product in the hive that is not safe for use during honey production, you should not extract and consume that honey.

Q. Last week you said that honey treated by oxalic acid could not be consumed. Can you give an explanation as to why it cannot be consumed?

A. Its safety for human consumption has not been evaluated by the EPA.

Q. Important: I treated with oxalic acid last year, so that honey is unfit for human consumption. If I feed it to my bees this year, will THIS year’s honey also be unfit for human consumption?

A. It should be fine for human consumption after the bees process it.

Q. Please define FOB—how many bees does it take to consider as a “frame of bees”?

A. Look here:

Q. I had previously been chemical free using genetics with VSH queens but have found about only 1 out of 8 queens displaying the hygienic trait. Is this a common finding? If so, what is being done to improve the expression of the trait. It’s getting expensive to keep paying more for queens that aren’t expressing the trait. I have started treating the hive prior to requeening to at least give the queen a better chance of keeping the mites down instead of starting in a hive with high counts.

A. F2 queens show significant dilution of VSH genetics. Might be worth buying a new queen from a VSH supplier if you want to keep those genes going strong.

I generally don’t let them make their own queens because of dilution and replace with new purchased queen. We do see a dilution of the VSH genetics over time as queens are replaced and mate with drones from neighboring apiaries.

Q. If you purchase a queen from Mann Lake or Better Bee, how can you be certain of the traits... It seems like they may say it has traits for a marketing sell.

A. You can ask them if they have done any testing of their queens against varroa mites.

Q. I found two dead white bees outside of an overwintered hive. What are your thoughts?

A. They might be aborted pupa or adult bees that were sun bleached. Keep an eye out and if you see anymore try and figure out what is causing it.

Q. My bees would not use the drone brood frame for drones. They built comb, the same size of the drone comb, but they filled it with honey.

A. This is not unusual. One thing you can do to make the drone frames more attractive is to spread a coating of wax on the frame using some melted capping wax and a paint roller and make sure you place them near the center of the hive where brood is normally found.

Q. I split my strong colony and the split box has queen cells on the foundations. Should I purchase a queen or wait for a queen to be purchased and use a mated queen.

A. If you like the genetics of that hive you can let them make their own. If it doesn’t work out you can always recombine later.

Q. How can we mitigate the problem of acaricides residue in various bee products?

A. Rotating comb on a 3–5 year cycle can help reduce the residuals in a hive. Every year remove your two oldest frames per box and install new foundation. At the end of 5 years you will have rotated all the frames.

Q. I missed some of this and am unsure what you mean by rotate entrances. Would this just be flipping from small entrance to larger entrance, or would it be more like flipping the entrance from the U facing up to the U facing down?

A. Switching from one entrance east, the other west—the idea is to reduce drift.

Q. Do you ever use honey frames or drawn comb from dead-outs?

A. As long as the cause of death was not AFB, the frames and drawn comb can be reused. I usually suggest rotating out old comb on a schedule to reduce pesticide and pathogen buildup.