varroa mites

August is a critical time for mite management

Varroa mite inside a hive. Pixabay

In late summer, the number of bees in a colony drops, but the number of mites continues to rise. If not treated, a colony will soon be swamped in a sea of mites.

In the temperate regions of the northern hemisphere, August is a critical time for mite management. Every year I find it hard to think about mites during spring and summer since they are nearly invisible. At that time of year, nearly 90% of all mites hide within the capped brood cells, out of our sight and mind. So unless you are in the habit of plucking pupae from their cells, you hardly ever see a mite. Your sticky board counts are low and your colonies are booming. Mites, it seems, are not the problem everyone talks about.

But it all changes in the eighth month. Sort of. It actually began to change at the summer solstice, back in June. That’s when your colony growth rate began to level off. Although hardly noticeable at first, the queen lays fewer and fewer eggs per day as summer progresses. As a result, the colony gradually shrinks as the weather warms into July and August.

Mite populations rise as bee populations fall

But while the bee population declines, the mite population continues to rise. More gravid female mites roam the hive looking for soon-to-be-capped brood cells where they can lay their eggs. If there are not enough brood cells, the mites will even double up and share the ones available. And by August, the colony is tired of drones and is actively expelling them. The queen isn’t laying many drones either, so all the female mites opt for what remains: worker brood.

Left untreated, an average-sized colony that may have had 6 mites per 100 bees at the end of June, may find itself hosting 35 mites per 100 bees by September 1. That’s a nearly seven-fold increase. Assuming you started the season with zero mites, the rate of increase is dependent on the number of mites that joined your colony during the spring and summer.

Mites can arrive in many ways but drifting bees, especially drones, probably bring in the most. A colony with ten introductions could end up with five times as many mites as a colony with two introductions, depending on when they occurred.

More mites carry disease to more bees

A six- or seven-fold increase in the number of mites per bee means a similar increase in the number of bees infected with the viral diseases that mites spread. Worse, by fall the mites the drones are not divided between the drones and workers but reside on the workers alone.

While the number of mites per bee gradually rises in June and July, by August it literally explodes. Unfortunately—and here is the real kicker—the worker bees reared in September and October are the bees that will see the colony through until next spring.

Winter bees can’t afford to be sick

While a spring or summer forager may live a mere four to six weeks, a so-called winter bee (or diutinus bee) may live up to nine months. Since these long-lived bees care for the colony during the cold and confined winter months, they cannot be sick at the beginning or the colony will not survive.

To raise healthy bees in September and October, your colony needs to be virtually mite-free by the end of August, the very month that the mites-per-bee ratio explodes. So if you are going to treat your hives, August is the month to do it.

Timing is everything

For many years, I read that any mite treatments should be completed by August 31. But lately, I’ve noticed that many groups are recommending an August 15 completion date for the best shot at healthy winter colonies. That means if you are doing a three-week course of something like ApiLife VAR, you should have already started.

Many beekeepers like to treat the mites in August and then again in the dead of winter when little capped brood is present. A second treatment in winter may be especially important in very strong colonies that robbed other colonies in the fall. Robbers often attack a weak colony that is dying. In addition to bringing home the honey, they bring home the mites as well.

But however you decide to proceed, remember that timing is everything. The ultimate goal is to raise a crop of disease-free bees that can take care of themselves from fall until spring.

Honey Bee Suite

Varroa destructor on honey bee pupa 640px
August is a critical time for mite management because the number of mites per bee increases drastically as the bee population decreases. Varroa destructor on honey bee pupa. Photo by Gilles San Martin from Namur, Belgium [CC BY-SA 2.0], via Wikimedia Commons


  • How do bees that don’t have the benefit of a beekeeper ever manage to make it through the many thousands of years without human intervention? From what I can observe of wild hives (in trees and such), there is no natural mechanism that seems to provide the colonies with insecticides to kill mites? So how come the earth still has lots of bees, even before there were beekeepers dosing them with insecticides?

    • Honey bees evolved in different part of the world where each group had its own diseases and parasites that they evolved with. And like you said, they did it over millions of years. It all worked fine without us. In fact, it all worked fine because they didn’t have us.

      But then we humans came along and within just a few hundred years, everything changed. Using planes, ships, cars, trucks, and trains we transported species from where they evolved to everywhere else. So for example, European honey bees which did not evolve with Varroa mites suddenly have to contend with them. They’ve only had a few decades of exposure, so of course they haven’t been able to evolve defenses because there hasn’t been enough time.

      The answer to your question is in your first sentence. Those original bees didn’t have the “benefit” of a beekeeper, but they also didn’t have humans spreading diseases and parasites all over the planet. Bee populations were isolated. Their problems were isolated. We humans took all these species and threw them into a big pot where nothing evolved with anything else.

      After the introduction of Varroa mites to the United States in the 1980s, the wild and feral honey bee populations were nearly wiped out. It appears that now there are patches, small wild populations here and there, that are showing positive sign of Varroa resistance. That is cause for hope.

      Of the colonies you see in trees and such, some may have Varroa resistance and be thriving, but some may be recent escapees from managed hives. Those escapees can last a couple of years in the wild before they die, so it is difficult to know their situation from just a brief look.

      You say the world still has lots and lots of bees. That’s true, but it doesn’t have as many as it used to. Bees in general are not doing well. All bees are having problems from the diseases we spread all over the world, to destruction of their environments and damage to their food supplies. What we have done to the planet is not pretty. People talk about letting nature take its course. But what nature? We’ve pretty much wiped it out. The world that bees evolved in has disappeared and that’s why we must care for the ones that are left.

      On a separate note, insecticides are not used to kill mites. Insecticides kill insects. Varroa mites are not insects, but are arachnids. They require different control measures called miticides or acaricides. This is a fundamental reason why we can sometimes use compounds on bees to kill the mites. If mites were also insects, it would be much harder to do.

  • Great reminder, Rusty. How do you like to count, and what infestation numbers do you use for treatment levels? I am doing sugar roll testing with the UMN Gizmo device (from Kelley) this year – my first time using the device. I have seen an occasional bee with DWV, even though my queen is meant to be VSH. I am afraid that I believe that I can’t trust the genetics, and as I only have 2 hives, I can’t afford the survivor approach either – I just need to know for sure.

    • Dawn,

      With a sugar roll, I usually treat at three or more mites per 100 bees. That usually means you have 6 or more mites per 100 bees once you include brood. Some people wait until they see 5 or more. I’m not saying my way is the best, that’s just the way I do it. I don’t worry as much about an occasional case of deformed wings because deformed wings can arise from more than one reason. Although, if I see multiple cases of deformed wings, I assume mites.

  • Rusty,

    I still have my honey supers on. I have a first year colony that started out with fully drawn frames and loads of capped honey left over from a hive that didn’t make it through last winter. My most recent inspection looked good in terms of stored honey and brood activity in the deeps.

    I was hoping to leave the supers on a few more weeks as one is almost full and the other getting worked on. Should I just harvest what I have now so I can treat, and be grateful that I got anything at all year 1?

    Should I do a sugar shake before treatment or just treat to be safe?

    BTW, we are in CT, about an hour NE of NYC.

    • Barry,

      That’s a call only you can make. Mite-Away Quick Strips can be used with honey supers in place, so that may be an option. If you do a sugar roll count and find nothing significant, then you wouldn’t have to treat. If it were me, I would do a sugar roll and then decide.

  • The whole mite situation is terrible. We started raising Purdue ankle biters this year and it will be exciting to see if they kill mites at a rate the university claims. What’s really frustrating is that I can talk to 5 different local bee keepers who have healthy hives and all 5 have different methods, from a regimented schedule of treatment to only treating high mite count colonies (because you can only manage mites, you never really “win” the battle). Heck the most successful beekeeper I know doesn’t treat and believes in generational adaptation. I guess it comes down to your individual hive health, but I have a lot of sleepless night thinking of what to do about mites.

    • Alex,

      Terrible is right. I think mite management has to be a personal decision based on location, experience, philosophy, and one’s willingness (or not) to lose everything to the mites. I don’t think there is one right way to do it, and all the ways seem to have down sides. I believe overall colony health and diet play a major part in whether a colony can control mites. I don’t think good health assures survival, but poor health is a certain killer.

  • Rusty,

    That is very well said. I live is western Ohio and August/September treatment is tough here bc we have a HUGE goldenrod nectar flow that lasts into October. In fact The population in almost all of my hives are extremely high right now and will remain the same into October. Just a interesting bit of information for you, my friend who does not treat but prefers battling mites though breeding had a interesting theory. Instead of breeding out aggressive behavior he encourages it. About 75% of my bees came from him and I will say they are hard to work with at times but are tough as nails. He runs roughly 500-600 hives and averages less then a 3% loss so something he is doing must be working. With that said his bees are not for anyone who doesn’t want to wear anything other then a full suit!!!

    • Alex,

      I wouldn’t hesitate to keep aggressive bees if they could control the mites. Certainly a fair trade.

  • Hi Rusty,

    Another honey question. I have a hive that I did the sugar roll test on and I definitely need to treat that hive. Like a previous person stated, I still have my honey supers on. My thought was that I was going to leave them on to make sure the bees had stockpiled enough for their own use during winter. I am treating with Oxalic Acid using a vaporize inserted below my screened bottom board so to minimize coupling the bees. I’m still unsure how to manage the honey frames once I take them off. I wilk probably harvest some of the honey but not all. Will freezing the honey frames ruin the honey if I store them frozen for an extended period?

    • Paul,

      A couple of things here. Honey that will be used for winter feed can be left on during oxalic acid treatment. It is only honey for human consumption that needs to be removed. The EPA label says, “Do not use when honey supers are in place to prevent contamination of marketable honey.”

      Freezing is probably the best way to store honey. Most people don’t do it because it takes up lots of space. But long-term freezing is fantastic. If you freeze it in the frames, just make sure they are well wrapped in plastic to reduce condensation on the surface of the honey when it is removed from the freezer.

      • Hi Rusty, following your feedback regarding to storing honey supers, how could I store the medium supers with honey and nectar during mite treatment if I do not have access to a freezer?

          • After counting mites a few days ago in two of my hives i am planning to apply ApiLife Var and for the 21 days that last the treatment I need a place to storage my medium suppers that have some capped honey and uncapped as well. I do not have a spare freezer as many beekeper seems to have so I am not sure the best method/place to store them. Thanks in advance.

            • Diego,

              If wax moths are a problem, stack the boxes crisscross so that light gets into every box, and keep them away from insects. I stack mine crisscross in a shed with skylights so the sunlight shines down into every box. Wax moths will not lay eggs in the light. However, do not tightly enclose the frames or the combs may develop mold.

  • Feral colonies will usually swarm that helps with mites and we try to manage bees and keep them from swarming.

    • Randal,

      This is true. I think we put too much emphasis on swarm control, although it seems warranted in populous areas where people are freaked by swarms.

      • Whew! Glad to see the clarification! I just read this article because of some other recent updates. I wondered why anyone would purposely introduce “ankle-biting” bees – mine already go for my ankles every time. Also my left wrist – clearly, that black watchband is a real threat to any right-thinking bees. I wasn’t even in the hive yesterday, I was mowing. They let me know that THEIR front yard didn’t need any mowing, thank you.

        But to the topic – 3rd year beek, and I’m still struggling with the timing for treatments. Can’t do X if it’s too hot – which it generally is, in July/August here in TN; can’t do Y under some other circumstances which I so far haven’t been able to time correctly; don’t like the caveats/risks about using Z; and I can’t do any of them when a family catastrophe intervenes and I have to leave town for 2 weeks. I’ve about settled on oxalic drip as something I’m actually willing to do, but again, I’m nearly stumped by the coordination. I guess I can drip even with brood present, as long as I’m willing to treat again later, yes?

        • I hear you as regards the timing and conditions of mite treatments, which is why I have defaulted to HopGuard. It has the fewest conditions, you can use it during a honey flow, and it won’t kill bees. The downside is messiness, but HopGuard III is way less drippy than I and II. I get excellent mite control with the fewest drawbacks with HopGuard, so I’m sticking with it.

          Yes, you may have to treat multiple times with oxalic drip to get the newly emerging mites. However, some people think multiple drip applications are hard on the queen, so that is the downside.

          Oh yes, my bees have a taste for ankles as well. It’s the only spot where I’ve received more than 20 stings at a time.

  • I know that Micheal Bush, among others, promotes the use of small cell bees (Bush calls it natural cell size) to help keep varroa populations down. Have you done any type of comparisons with this?

    Everything I’ve seen on this is compelling but I don’t know how much has been done in the form of a proper scientific experiment. Most beeks just don’t have the background to run such experiments. As I recall, you have the training and background to do so.

    • Craig,

      “Small cell” refers to pressed foundation that has a cell diameter of 4.9 mm. “Natural cell” refers to cells that are built naturally by the bees with no foundation to guide them. Bush uses natural cell almost exclusively (at least at the last time I heard him speak). What that usually means is there is a range of cell sizes, most of them smaller than standard commercial foundation, but not necessarily 4.9 mm.

      That said, I hold the unpopular opinion that cell size has no affect on Varroa mites.

  • This is my first year caring for bees, & I received my first colony pretty late (June 15); the person I purchased the nuc from doesn’t treat, & my bees came with a pretty high mite count, so I treated with 1 strip of MAQS, to great success, though I haven’t done any counts yet, other than mite drop on the tray in my SBB. I’m seeing few mites, if any (last count was 9 mites over 4 days).

    My question is whether or not I should do a count using a roll method, treat regardless as a preventive measure, or assume that everyone is doing well based on low mite drop counts?

    I’m also having a heck of a time with wasps near my hive, & just replaced my robber screen last night, after only using a reducer. With that, I’m going to remove my tray, to increase hive ventilation, so I really won’t be able to do mite counts. Would this affect a decision on treatment plans? (I live in Delta, BC) Thanks for your help!

    • Loralei,

      I like to keep bees based on the facts I find in the hive. So I would definitely do a test, probably a sugar roll, to determine the situation. I don’t like to treat proactively, because that tends to increase resistance in the long run. You can do a sugar roll test without harming the bees, and then you can make an informed decision on treating.

      Btw, you did the right thing with the wasps. Good decision.

      • Thanks very much for the advice, Rusty – I appreciate your taking the time – I’ve scheduled a roll for next week, after the pollen patty that I placed recently is consumed 🙂

  • As a hobbeeist with just 4 hives, I have also been considering the idea of a “fall split” as part of August management. I live in PA, and so I am prepping for overwintering. Are splits okay in August? I have one target hive that is loaded with festooning bees – top to bottom (one deep, one medium and two full supers). My three other hives are not as lively (one nuc from a swarm, one deep hive, and one medium hive make up the 3 others). My other thought was just to open up the main hive’s brood by donating to the weaker hives in prep for winter.


    • Neil,

      You can do a split in August assuming you can get a mated queen from somewhere. It is getting late to mate one locally. My drones are mostly expelled by the end of August, and that probably holds true in your area as well.

      However, unless I am misreading this, it seems like your colonies are small. It is my understanding that most Pennsylvania beekeepers like to overwinter in two deeps or three mediums, all packed with winter stores. You have long and cold winters which will require lots of honey. You can equalize your colony strength, as you mention, and that might be your best bet.

  • Randy

    Mann Lake is requiring an applicator’s license to ship Mite-Away Quick Strips. The rules seem pretty arbitrary. Hop-Guard was available in CA at first and then became restricted.

    I recently tried your oaxalic acid drip and have yet to know how it worked.
    Do you recommend any other commercial options that aren’t restricted?


    • Carter,

      You must live in California? I think California is the only state that requires an applicator’s license. I recently ordered HopGuard II from Mann Lake in California and they shipped to Washington, no questions asked. But as far as other commercial options, I don’t know the extent of California’s law, except that it recently got much more restrictive. The fact that I think the law is stupid won’t help you.

  • Hi Rusty,

    This is my first comment/question, admittedly I feel like a kid asking for an autograph from her idol. I love your blog, I’ve laughed and learned more from your website than anywhere else. Thank you for the information you research and put out there for us to find and for sharing your personal stories. Your personal stories leave me with a chuckle and a sigh of relief, “at least I’m not the only one!”

    I realize someone asked you previously about the Purdue ankle biters, I was wondering if you have any additional information about them. I have been offered the opportunity to re-queen my failing queen with a Purdue Ankle Biter queen. While I understand their desirable traits, I have been unable to find any information regarding their disposition. Even the breeder I am getting her from has not had her long enough to know what disposition will show up. Have you had any experience with these queens and their offspring or have you heard from anyone that has?

    While I am excited to try something new, I have young children that help me with the hives (my 9 year old has her own hive this year!) so I aim to keep docile bees. I worry that the aggression these bees show towards smaller ‘bugs’ could transfer to aggression at the large beast peeking into their home.

    Thank you!

    • Heather,

      Your generous compliment made my day. Thank you!

      As for ankle biters, I have no experience but I would jump at the chance to try them. I have not heard anything negative (or positive) about their disposition, which leads me to believe it is probably not remarkable one way or the other. If they were exceptionally mean, I think I would have heard by now.

      One thing to remember is that aggressive biting behavior is biologically different from aggressive stinging behavior. I don’t think you can conclude that because they like to bite parasites in the nest that they also like to sting animals in the field. They seem like two very different responses to different situations. If the behaviors are controlled by different genes, the responses are probably not related. Again, I’m only speculating, but that would be my guess.

      As I said, I would be eager to try them. If ultimately you find the offspring too aggressive for your taste, you can always re-queen again.

      If you go for the ankle biter, please write and tell me your experience with her. I’m really interested.

      • Just a quick update, queens were installed 6 weeks ago. I left the queens caged until the bees released her. 1 queen disappeared (I think she was killed during a yellow jacket robbing) but the other queen has settled in and is laying like a champ. I checked the hive yesterday (Sunday) and the bees were so mellow I didn’t even need smoke. They were so quiet I couldn’t even hear them buzz until I popped a propolis lock off the inner cover. Even then, they buzzed for a millisecond and then, it sounded like, they decided it was too much effort to buzz and went about their business. I pulled frames, shook bees from frames, moved things around to get ready for winter, all the while none of the bees cared. The entrance was busy with bees ‘coming home’ as the sun was getting quite low while I worked, still, the bees didn’t care. So far, I’m very impressed with the temperament!

  • Rusty,

    I think I will just boost out my weakest hives by having my best hive donate some frames as August rounds out. Will the weaker colonies accept a frame or two of bees from another hive without getting hostle or protective? Will they accept the strangers?



    • Neil,

      Weak hives are often not in the position to fight. But if the brood is ready to hatch, you can knock off the workers and just add the brood. If you want to add some of the workers as well, use plenty of smoke.

  • Hi Rusty,

    I’m working with ankle biters in Seattle and they typically need smoke and gloves to work. They do have a little fight to them but there is some price to pay for having bees that want to survive. I have also run into the occasional CA packages that have been equally or more aggressive. The bees are completely workable with smoke, gentle hands and good weather.

    – Jeff

    • Thank you for sharing your experience, that’s exactly what I was looking for. I’m ok with needing smoke and gloves. My kids are fully suited up when they check hives with me.
      I have decided to go ahead and try the AB queen. The breeder offered me an additional queen so I will have 2 hives to compare against each other. Rusty, I’ll let you know how it goes!

  • I have a colony that I thought lost its queen because there was no eggs or brood. I re-queened and they just killed her. I tested them with a frame of eggs and open larva from my 2nd hive which they just capped up. I’m told I may have a virgin queen as there were some older emergency cells that were opened. Yesterday I found one cell with 2 eggs in it (the bottom) and a couple of cells with royal jelly in them. This all started around the middle of June. Is there a chance my virgin queen has been bred or do I have a worker starting to lay and what’s with the royal jelly? The hive has been dwindling over the summer. Is there anything I can do to save it now? This is just my 2nd year with bees and last year seemed so easy.

    • Susan,

      I’m not sure I understand. If the bees have been queenless for a while and then killed a newly introduced queen, you could very will have laying workers. That said, seeing only one cell with multiple eggs is not definitive, because some queens lay multiple eggs just after they are mated. I don’t know what you mean by “I tested them with a frame of eggs and open larva from my 2nd hive which they just capped up.” Do you mean they didn’t build queen cells? Are you sure it is royal jelly in the empty cells? I’m not sure why that would be. It sounds like the colony won’t make it. Perhaps you could combine it with your larger colony, but even that can be tricky, especially if you really do have laying workers.

  • I’ve noticed that some of my orchard bees seem to be heavily infested with mites on emerging. Are they Varroa? Is there a risk of cross contamination with honey bees and vice versa?


    • Cyrus,

      The mites you see on orchard mason bees are Chaetodactylus, also known as the hairy-footed mite or pollen mite. They eat pollen, but reproduce inside the nest with the developing bee. The are pretty much confined to bees in the Megachilidae family. They cannot infect honey bees because their life cycle does not mesh with the honey bee life cycle, just as Varroa cannot infect your orchard bees.

  • Hi there! Rusty, thank you for all of the work you put into this blog…I have come to rely on it as one of my primary go-to resources for beekeeping info specific to western Washington.

    I was curious if anybody can speak to how well the Purdue “ankle-biters” overwinter here in W. WA?

    Also, have you heard about the even more parasite hostile “mite-mauler” bees that actually chew on the mites’ bodies?

    • Julia,

      I read about these often, but like any strain of honey bees, their genetics washes out very quickly and is usually completely gone by the third generation. Bees are hard to control, so after the bees replace the queen with another that is bred to local drones, there isn’t much left of the genetics that made them special. Not to say this work shouldn’t be done because it should be, and we learn a lot from it. But it’s hard for someone who is not isolated from other colonies to make these things work over the long haul. If you are isolated, or if you have enough colonies that you basically can control the drones’ genetics, then it might be worth it.

      • What you say is a little disheartening, but makes total sense. Of course, if one only requeens every other year, assuming everything else went reasonably well, a person could get at least 4 good years out of a queen purchase.

        I read/heard somewhere, probably a recorded Landi Simone lecture or the like, of a guy who engaged in breeding mite-resistant queens of some sort, and gave them to beekeepers all over his county in an effort to bring down the mite population. Apparently he had some success with it…

        • Julia,

          Mite-resistant stock works best when you can influence most of the bees in your area, especially the drones. So providing local beekeepers with mite-resistant queens could have a huge influence.

  • Hi Rusty, I need to make sure I get all this straight. I have a few questions.

    1. You said you use the oxalic drip after the winter solstice and that you always use “soft treatments”. Which treatment do you use in August?

    2. I see where you have used Apiguard and Api Life Var . Do you still use these? Do you have a preference?

    3. Do you usually only treat in August and after the winter solstice?

    4. I checked my hives this weekend using a varroa board with oil on it. Out of 3 hives only one had one mite. I will keep checking through out June.

    5. If I see mites in June can I wait and just do my treatment that would end in August? I’m concerned about doing treatments too close together otherwise.

    6. I see where you were not happy with HopGuard. Has your opinion changed on this one at all?

    7. Last but not least. I have a horizontal hive (new this year) Trying to figure out how to use oxalic vaporizer on it in the winter. Any thoughts or ideas?

    Thanks again Rusty I appreciate all your help.

    • Linda,

      Q. You said you use the oxalic drip after the winter solstice and that you always use “soft treatments”. Which treatment do you use in August?
      A. In August I use formic, thymol, or hop-beta acids. The term “soft treatment” refers to compounds derived from nature (although they are much stronger) as opposed to chemicals that were designed in a lab.

      Q. I see where you have used Apiguard and ApiLife Var. Do you still use these? Do you have a preference?
      A. Yes. No.

      Q. Do you usually only treat in August and after the winter solstice?
      A. Usually, but it depends on my mite counts.

      Q. I checked my hives this weekend using a varroa board with oil on it. Out of 3 hives only one had one mite. I will keep checking through out June.
      A. White boards are not reliable. You should use a sugar roll or alcohol wash. In any case, at this time of year when there is so much brood, most mites are well hidden.

      Q. If I see mites in June can I wait and just do my treatment that would end in August? I’m concerned about doing treatments too close together otherwise.
      A. It depends on how many mites you see in June. If there are a lot, the colonies may not make it till August.

      Q. I see where you were not happy with HopGuard. Has your opinion changed on this one at all?
      A. My opinion has not changed on the original HopGuard, but I like HopGuard II.

      Q. Last but not least. I have a horizontal hive (new this year) Trying to figure out how to use oxalic vaporizer on it in the winter. Any thoughts or ideas?
      A. Unless I know how the hive is designed, I couldn’t say. They are all different.

  • I wanted to say I enjoy reading your writing and tweets too. I am a seventh year bee keeper and traditionalist. I have read many “old” beekeeping books, etc. and I spend countless hours sitting, watching and listening to my bees. I have four top bar hives and a Langstroth hive which I’ve converted to using top bars. I do not vent my hives at all ever. Personally and from reading etc. I believe that may be one of the reasons for mite infestation. From what I have gleaned mites like the temperature and humidity lower than the average bee hive. Guess what happens when you vent? Right, both temperature and humidity drop. I am not saying I haven’t lost hives- I have but it was not due to mites. Keep the temperature and humidity high- the bees love it and the water condensing on the walls of the hive is the perfect drinking water source for the bees! Also I hear of some bee keepers inspecting their hives 6 times a month and more and I wonder why they think bees make and use propolis? Opening a bee hive is a little like a home invasion and I think inspections should only be done for a good reason. Rusty, you actually wrote and tweeted a great article on this so thank you. It was well written. So I say watch and listen to your bees and disturb them gently and only occasionally. Do nothing that you don’t see happening in nature! So don’t vent. The bees know what to do and instead of thinking you know best watch and learn from the masters- the bees themselves.

    • Peter,

      I believe the real problem is that Apis mellifera didn’t evolve alongside Varroa destructor. There is no extended history of the two species living together. The mites jumped species from Apis cerana, so this is all new to our honey bees. Give them a few thousand years and they’ll have it all sorted out.

  • Rusty- sure enjoy the excellent interchange you create here.
    I’m a multi generational bee observing possessor and this year decided to beek.
    Any general wisdom you can offer starting this at 19th Lat., Hawaii ? Do’s, don’ts ?

  • Hi Rusty,

    I have two hives, each in a single deep. I want to treat with Apiguard but I’m not sure if I should use a full
    dose or a half rose. Their literature says use a half dose on small or weak hives. Their video demonstrates how to apply a full dose and they do it on a single deep. I wouldn’t call my hives weak but what is the definition of small? I don’t want to use too much and harm the hive but don’t want to use too little and not be effective. Any thoughts?


    • The Apiguard website says, “Apiguard gel comes in 50g ready-to-use aluminium trays (two will treat one standard colony).” Later it says, you can use half that for “nucleii and very small colonies”

      Reading between the lines, I would say a nuc is generally 4 to 5 frames of bees, both sides. So if it is larger, I would use two. Personally, I would probably go to two at about 6 frames, both sides.

  • Hi Rusty.
    I read recently about some beekeepers in Canada (I want to say Southern Ontarior or Southern Quebec) that were trying out a special mite that kills varroa mites. I’ve lost the article, but it was a much smaller mite than a varroa that bites off the legs and head of a varroa. Apparently the plant nurseries use it to control issues in greenhouses. They did a small control test that looked promising. Have you heard anything about this? Thanks, Vikki

  • Yes, that is the mite. Niagara Beeways has a video on them on Youtube and they sounded promising. It looks to me like you would need to sprinkle them on you hive in the spring and in the fall. I just tried it. I sprinkled the mite medium (mostly vermiculite) on top of the frames, just under the inner cover. The bees cleaned it all out within a day, but I am hopeful that as they traveled downwards, they left some of the mites in the brood chamber. I may treat them once more this fall. And then we will see…… Have you tried it yet??
    Here is the link I read about these.

  • Hi Rusty – I just extracted honey last week but left tons for the bees. I only pulled a few frames from one of my supers (I have two on). The bottom super was mostly capped so I took 4 frames of 10. The upper supper was mostly uncapped so I left all of it. I would like to treat for mites as I’ve seen them in Drone brood but not physically on the bees (at least not those I examined with several close of photos). To treat, I know I shouldn’t have honey supers on but at the same time I figure the supplies are good for the winter.

    My thinking is to use a fume board to push the bees down into the bottom two brood boxes (deeps), pull the supers, treat with OA and replace one super after a couple of days and freeze the other for spring.

    Does this sound reasonable? The brood boxes look good with brood, honey and other stores but I’ve been told to leave one honey super for the bees to ensure they have enough for the winter.

    I’m on the other side of puget sounds so similar weather conditions.

    I put my wet frames back in the hive to allow the bees to clean them. I read elsewhere on the blog that another strategy may be to put my mostly uncapped frames above the inner cover. That may work well but still can’t do that if I treat and hope to use those frames for honey in future.

    Any recommendations would be helpful.

    • Sean,

      You don’t want oxalic acid in the honey to be used for human consumption, but if the honey in the supers is for winter feed, it doesn’t matter. You can leave it on or not.

      The best way to determine if you have enough honey for winter is to count frames. I’m extra conservative and usually leave about 80 pounds in place. You can probably do with less if you monitor them. A deep frame of honey, both sides weighs about 8.5 pounds, and a full medium, both sides, weighs about 6 pounds. So just count frames and you will know how much to leave.

  • Hi Rusty, don’t want to sound cliche, bit LOVE this forum and your answers and generosity for sharing. Newbee here, and am completely hooked on these bees!

    I started this spring in Ontario (Canada eh?), and with my late start and wet season, the girls did not do anything on my honey super that I put on beginning of August. Last week’s inspection showed tons of honey in both of my deep brood boxes so I did pull one deep frame last weekend (and will replace with an empty one today) and pulled off the empty super to start medication and winter prep. Now that I started my medications, Murphys law has decided to give us some late summer weather and I suspect we may get an Indian summer to make up for the summer we didn’t have! I’m a bit worried that the bees are going to get crowded and want to swarm now that I’m feeding (for the medication) and that there is no super to go to. My top deep was stuffed with capped honey last week (almost all frames) and the bottom chamber had 5 full frames of capped honey and about 5 frames of emptyish brood frames. I suspect the brood frames will be full of brood when I inspect later today thanks to superb weather last week.

    Can I put the empty super back on in the hopes they can draw some foundation for next year and so that they have room to go to while the weather is awesome and they are getting fed? (Remember the brood boxes were full of honey). Not sure if this will take too much energy for them at this point in the season, or if I’d be able to eat that honey next year from drawn medicated comb, but feel they need some space. Or should/could I pull another brood honey frame and freeze for the winter and have them work on a couple empty frames to give them workspace? Again, just worried since there are many bees and weather looks like it will stay.

    Finally, if you do freeze frames with plan to return in winter, how do you do this? Do you open up box during cold weather and trade with an empty frame which seems like it would chill that brood box, or do you put on an empty super above the inner cover (but I assume they can’t break cluster to go get that honey in winter?) Sorry for so many questions! Love all you beekeepers. Thanks for sharing, from your friends up north!!!

    • Julia,

      I don’t think a late-summer warm spell will make much difference in the amount of brood in your hives. The colony is more influenced by the approach of winter and the shortening day length than they are about a few warm days. If you haven’t, read “Your beekeeping year is about to change.” Basically, this is the half of the year where colonies are shrinking. Many will soon enter a broodless period that can last from one to three months. For more see, “My hive have no brood.”

      Remember too that under normal circumstances, your bees won’t swarm now. Swarm season is long past, and many colonies don’t even have drones now, which makes reproductive swarming impossible. A colony might abscond if they don’t think they can survive where they are, but that sounds unlikely.

      Also, colonies are highly unlikely to build comb at this time of year. It’s not something they normally do in the fall because it is energy wasteful. If they do build some, it won’t be much.

      There is nothing wrong with opening a hive in winter, especially on a warmish day. Anything above freezing works really well, or even less, if you are quick. Regardless of the conventional wisdom, you often do much more good than harm by opening a hive and repositioning the food.

  • Hello Rusty

    I am treating my hives for mites this year with Apiguard. Today is the start of my fourth week so technically I would be done this next Monday. I am still seeing a large mite drop and it concerns me. The bees have been coming back absolutely loaded with pollen so it is possible that the mites are simply just hitching a ride back to the hive. I plan on doing another mite count at the end of the week but what do I do if it is high. Is it unheard of to do a third round of Apiguard? Should I maybe hit them with OA vapor instead?? I was already planning on an OA vapor treatment some time around the winter solstice but if my mite count is high I may not be able to wait that long. Have you ever experienced this same thing? What did you do? I do feel like I got a late start this year but I had a lot of uncapped honey and I was trying to wait so that the bees would seal as much of it as possible.

    • Paul,

      Yes, I’ve had mite treatments not work, or not work as well as I had hoped. I would treat again, but I would definitely change products. If you can go with OA, try that.

  • Hi, Rusty

    I did a sugar roll yesterday, and at a 2% estimated infection rate, I am planning on applying MAQS. The supers are off, but there is still quite a bit of capped brood, so I don’t think thymol is the right treatment at this time.

    My question is, have you given any more thought to the pros and cons of proactive treatment? The tests are invasive and I have never tested and NOT found mites. I am wondering if I should leave the bees alone more and just treat early spring with thymol, mid season with MAQS and then OA in the winter.


    • Barry,

      After many years of always finding mites, I didn’t find treatable levels this year. I have no idea what’s going on, but if I get away without treating, I will.

      • Hey Rusty,

        First, I love your site. It is so informative especially for those new to beekeeping! I have been reading for a few years now but just now am having an opportunity to get 2 hives. I will be getting his hives later this week. I will obviously need to test for mites once I have them. The current owner told me he tested one hive with a sticky board and it had 1 mite per inch in a double deep. That seemed high to me but he doesn’t seem concerned. For what it’s worth they are double deeps and we are in Indiana. If levels are high is it too late to treat them and have an impact before winter? From what I read MAQS may be my best bet at this point because it only need 7 days if it’s needed at all but I wanted to get your thoughts. Thanks!

        • Matt,

          One mite per inch sounds high, although that’s an odd way to count them. I would treat to be on the safe side and, yes, MAQS would be fine.

  • So I have done so much reading about using OA vapor when capped brood is present. Some say 3 treatments in 5 day interval is the way to go…while others say 3 treatments in 7 day intervals.

    Could you shed light on what you think is most effective? I’m in Texas…drones production is pretty much obsolete so don’t really need to factor them into the equation right now.

  • Rusty, I am so stressed out about this very subject! It’s been too hot to apply the Formic Pro I thought I would try. But it will be at least another week or two until the heatwave subsides. Think I’ll be okay in central NH getting my August mite treatment done by the 30th instead of the 15th? Stressed! Thank you, Suz

  • Hi Rusty, It’s mid-August and I was going to use oxalic acid to treat my hives with a Varrox vaporizer this weekend. However, the instructions say only to use on broodless hives which would be mid or even late October where I live.
    My understanding is that the vaporization won’t hurt the brood, it just won’t kill any mites already on them. Later in October I could repeat the treatment before winter settles in.

    What would you recommend? Should I go ahead and vaporize now and repeat later in the fall?

    Many thanks, Valerie

    • Valerie,

      You are correct that the vapor won’t hurt the brood, it just won’t kill the mites under the caps. If you want to do a treatment now to knock back the mite count, you can do that. Then later, with no brood present, you can do another treatment.

  • Wow, I don’t think I had blinked before you wrote back! Thanks so much for your help with this and the 10,000 other questions I’ve had over the years. You’re the best, Rusty.

  • Rusty,

    The question I have today is about treating with Formic Pro in a hive which I feel sure is in the process of replacing the queen. At first I thought they may preparing to swarm, but after a thorough inspection last week, noticing the low number of queen cells, the location of the cells, and the overall condition of the hive, I truly believe they are just replacing the queen. In fact, I think the previous queen has died already because I saw no sign of her at all. But as many bees as there are in there, it’s a good possibility I just missed her. This hive is from a swarm I caught at the first of May and is now incredibly strong. In the case that I have made a correct assumption about supersedure, should I wait to treat for mites with Formic Pro until after I have a newly-mated queen or is it ok to treat beforehand? Last week, the queen cells were still capped. I wasn’t sure if the treatment would hinder the queen from taking her mating flight or possibly kill her. To be honest, I haven’t completed a mite check yet, but after losing several hives last year due to mites (even after checking and treating), I feel I need to treat regardless. I did notice several mites on the bees during my last inspection so that made me a little nervous!! Even though there is a break in the brood cycle, I should still treat, correct??

  • Rusty,

    First of all, thank you for always taking the time to provide me with some good information on questions I have about the complicated task of beekeeping. The question I have today is about treating for mites using Formic Pro…I currently only have 2 hives. One of my hives is from a swarm caught in a trap on May 1st which is now incredibly strong, in fact, they are 3 deep high. I noticed in my inspection last week that they were in the process of replacing the queen for whatever reason, and it seemed like a queen was fairly close to emerging. Today, some of the queen cells were open, so I’m assuming they are close to having a mated queen (hopefully). Let me say I have not done a mite count yet, but plan to this week. If the mite count is high, when is the best way to treat using Formic Pro in this situation? Will the treatment hinder the queen from mating or cause the bees to reject her if I treat now. Should I wait until the queen is laying before I treat? Will the break in the brood allow me to treat a little later without too many consequences? I’m prepared to treat if I get a high mite count, but I don’t want to hinder the new queen. I also don’t want to wait too late and lose the hive. One other question is, should I need to treat, where would you place the Formic Pro in a hive that is 3 deep high? Ordinarily, I put it on the top bars of the top box of a 2 deep hive, but what about having 3 deeps?

  • Hi Rusty,

    This is my first year of beekeeping. Bees (Saskatraz) were installed on 5/2. I have 2 deep brood boxes and a medium honey super. On 7/14 I did a sugar roll test and found 0 mites. Thinking that was too good to be true, I did an alcohol wash on 7/28 and found 3 mites. I figured I would do one more alcohol wash in 10 days or so, which would be about 8/7. Is that too soon to do another alcohol wash? I have a slatted board, screened bottom board and the sticky board that I will put on if/when I do a treatment. I have both MAQS and Hopguard III. Based on the expiration of the products, I will probably use the MAQS now and the Hopguard III this coming Spring. Does this sound like a practical plan to you? Thank you.

    • Sheila,

      Since you recently did a mite check, you could just go ahead and treat with MAQs now and then do a follow-up check afterward to make sure it worked. You could do another one now, but I really don’t think it’s necessary.

  • Thank you for the response, Rusty. It came just in time; I was heading outside to do an alcohol wash!

    How soon after the MAQS treatment ends (I’m doing the 2 strips, 7-day method) would you suggest I test for mites again? And IF there still are lots of mites (hope not) I was thinking I’d do MAQS again, but am not sure if I should do it right away, or wait a bit. Can you steer me in the right direction on that?

    Thanks a lot. I really appreciate your help.

    • Sheila,

      I would check for mites right after the treatment is over. If you need to treat further, I would check the package insert for instructions.

  • Hi Rusty,

    I have two top bar hives in Portland started as packages this year.

    Do you feel it is okay to place Apiguard on the floor of a top bar hive to treat mites? If so, while the instructions suggest not feeding while it is used, it seems hard to avoid that at this time of year as I need to help them build up winter stores. Do you have any thoughts on this?


    • Doug,

      Different products have different temperature recommendations. Be sure to read the package insert or look them up online.

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