Archives for posts with tag: Varroa mite

It’s been a bit over a month since I’ve posted about the bees. It’s not that there isn’t anything interesting happening; au contraire! I’ve been busy with them, whether mine or someone else’s, nearly every weekend. I simply have not taken the time to organize my thoughts about what to write.

Since I began learning about beekeeping, I find myself questioning my own motives, as well as those of other well-meaning folks who want to help “save the bees”.  Non-native honeybees, as far as I can tell, are not the pollinators desperately in need of our help.  Humans generally recognize the importance of honeybees in pollinating our food crops and, since they are useful to us, these bees tend to receive the attention they need. Plus, the increased attention on honeybees has been instrumental in conversations to limit pesticide use, which helps far more species. So I’m not completely knocking the honeybee; rather, I am simply cautioning that there are native bee species who may need our care more.  What about species that aren’t as charismatic as our sweet little honeybee?

The diverse array of native bees, of which there are 1600 species in California alone, are left mostly to their own devices. Fitting, I suppose, since many are solitary bees.  However, to compound the issue, not only have we eliminated much of the native habitats and open spaces these species depend on for nesting and foraging, but the landscape is swarming in non-native honeybees who out-compete these locally-adapted species. Native bee species tend to be specialists that are evolved to forage on plants local to their environment. Non-native species, like honeybees, can take advantage of a wider variety of species, and in better pollinating them, help those to spread even wider.

So where does all this leave me and my wee colony of bees? Well, they are growing well. So well that I needed to buy an emergency extension when the equipment order did not arrive in time (a local beekeeper was generous and offered me a loan, but I was pretty sure I’d need the gear eventually). I don’t want to be a beekeeper who is casting swarms about willy-nilly and adding to the problem; I don’t think it’s particularly neighborly to do so when living in a residential area.

In my last hive inspection, I did a sugar roll to count the number of mites and found two, which equates to less than one mite per hundred bees and is in the acceptable limits. I’ll do another count in a week or so as part of Mite-a-Thon, a citizen science project to track mite numbers across North America.  I sent the inspection video to a few family members as a preview, and my mum supplied me with some questions that I’d like to answer here for her and others. I think my mum asks some pretty great questions about things that I tend to go over quickly or ignore assuming everyone knows what they are. Anywhoo, I hope you’ll find these interesting:

  1. Q: Did I ever find the queen? A: That day, nope, I don’t think I did; but there were other signs of her somewhat recent presence through young larvae.
  2. Q: What are those two cups for that were on the first few frames? A: Those are the start of queen cells, signs that the bees might be feeling a little cramped for space or that the queen isn’t doing an adequate job. Not things one wants to find in the colony, and signs that make finding either the queen or eggs important.
  3. Q: What was that white looking screen for? A: That is a queen excluder. The spacing is such that the larger-sized queen can’t get past it, but the workers can. It’s used for limiting where the queen can go and lay eggs.
  4. Q: Every time you inspect the hive, you have casualties? A: Yes, unfortunately. It’s one of the reasons to not inspect too frequently. Every 2 – 4 weeks is recommended, depending on timing and other considerations.
  5. Q: What do you think the bees think when you put all the sugar on them? A: “WTF, lady? Get this shit off of me!”
  6. Q: What happens with all those bees flying around afterwards? A: They all go back home. They know exactly where it is and will go back to their home with their queen, who is the only one that can reproduce. An individual bee can’t survive by herself. She needs the hive and her sisters for food, warmth, and protection.

I decided to check the colony one week after the first Apiguard treatment rather than waiting the full two weeks and discovered that the first patty was nearly finished. I am in a time crunch with rain arriving finally and plants soon to start blooming, so I am attempting the two patty treatment in a constricted timeframe. The colony appears strong despite the alarming number of mites I find on the sticky bottom board when I check it each morning. I’ve estimated 30 – 50 mites per day, with the numbers definitely falling over time; assuming a full hive body holds 20,000 – 30,000 bees that results in a 2 – 3.5% infestation rate, which is getting too high. According to Honey Bee Health a beekeeper should strive to keep the colony infestation below 3%.

My colony has filled all the frames now and there is no room for them to grow. They are apt to swarm if I don’t add more space for them soon. Some of the sites I’ve read recommend adding more space when the colony has filled six to eight frames in a ten frame box. Managed colonies expand by the beekeeper adding additional boxes with frames for the bees to build new comb. There is a balance to maintain because if there is too much empty space during the winter, it’s harder for the bees to maintain and protect their environment and it’s easier for intruders like wax moths or hive beetles to get a foothold into the colony. I am hoping that with the swath of lemonade berry about to bloom behind my property, there will be plenty of honey to keep the bees through next winter as well as a bit for my harvest. That means I need to add a super at a time when I am not also treating for varroa mites since the thymol treatment can lead to funky tasting honey. If it weren’t for my honey greed, I could have added another box at any time and just left whatever was produced for the bees.

Lush chaparral hillside

The timing of my inspection was not ideal as it was still a little too cold and most of the bees were in the hive rather than out foraging. That meant a lot of angry bees when I started peeking in their house! Here are links to the videos on YouTube if you’re interested in watching: inspection and summary. One note if you watch the second video, don’t do as I say and run and hide if bees are chasing you; if you safely can, calmly walk away. I tried to be quick about the inspection due to the weather, but became a bit disturbed when I could not locate the queen.

What I did find was several capped drone cells (I’ve highlighted them in the photo to the right) and one large bee sans blue dot. Last week I had found a couple drones, so I thought I knew how to distinguish them from the queen, but I’m clearly not confident in this.

Though this larger bee lacked the dot, I thought this was a queen due to a more elongated abdomen. It also seemed to have rather large eyes, a drone feature, so I clearly need more practice. Unfortunately, the bees were so upset that Marc, my super-handy husband and chief videographer (pictured to the left; yep, he needs a beesuit), was not able to get in close to get a photo for my later reference so it’s all a bit of a mystery for the moment. I did not find queen cells, neither supersedure, nor swarm cells, so I assume she’s there.

I’m going back in today to pull the second Apiguard treatment and add the honey super. My beekeeper friend is coming to help so we can be certain if the colony is queen-right. Wish us luck! It’s still a little cold.

I decided to try a prophylactic mite treatment for my hive after doing the powdered sugar roll a couple weeks ago. You may recall that my test failed due to operator error and it appeared that I did not have any mites. However, among beekeepers in this part of southern California it is known that no mites is highly unlikely, so I was fairly certain that I have mites in my colony; I had simply failed to detect them. I spoke with my beekeeper friend who shared with me some pictures of mites on the bottom boards of her colonies. We even played a little “Where’s Waldo”-esque game of Find the Mite to help me develop a good search image. Equipped with this information, I carefully searched the bottom board a few days later and I found a couple of the little buggers. (Side note: my aging eyes are getting more problematic. I’ve found that even wearing my glasses, the mites are too small for me to be certain of them so now I take a picture of the area where there is something that resembles a mite and then zoom the picture in closer to confirm. Perhaps I’ve found a use after all for Marc’s odd real estate gift magnifying glass he handed me a few weeks ago.)

European honeybees (Apis mellifera) are not co-evolved with the Varroa mite so they have not developed adequate adaptations to this threat, which they have only been dealing with since sometime in the 1960s for the species, and since the 1980s in North America. Varroa mites were originally known in Asia where they parasitize Asian honeybees (Apis cerana), a different, albeit sister, species. I’ve been looking into the array of methods one can use to treat for these mites and the reasons for and against treatment. As a biologist, I tend to agree with some of the treatment-free beekeepers I’ve read. In this philosophy, mite infestations are generally viewed as a genetic issue best handled by re-queening from a treatment-free breeder. A queen bred from stock that has survived without the use of chemical treatments should have genes better adapted to combating and co-existing with the mite. This is why I opted to purchase my queen where I did, since they have queens that have been selected for what is known as VSH, Varroa selective hygiene. Increased mite resistance is also one of the advantages for keeping feral colonies with some Africanized genetics who seem better-adapted to handling Varroa.

A powdered sugar dusting is one non-chemical method that can be used to encourage bees to clean themselves, which results in mite removal (Hive inspection video). This method does nothing for the mites that are busily reproducing in the capped brood cells, so multiple treatments are needed in quick succession to have any hope at reducing mite numbers. On some sites I’ve read that store-bought powdered sugar, which contains corn starch, is hazardous for bees and it’s recommended to make your own by putting granulated sugar into a blender. Other sites have cited research that cornstarch-laced powdered sugar is not harmful to bees, but other anti-caking agents are. I had powdered sugar on hand, so that’s what I used. After checking the bottom board this morning, I counted five mites. I’ll check the board again the next two days so I can get an average daily mite drop, and I’ll sugar them again in a week. Aside from the mites, the colony appears healthy. They are chugging through their sugar syrup and there were plenty of bees, capped brood, and capped honey visible on the few frames I pulled out.

Here I am sugaring the bees

So I’ve mentioned doing a mite check for a while now and finally did my first one over the Thanksgiving weekend. It was an epic fail that might be better described as a series of what not to do. I had read about the method I had selected; I probably should have looked online for a YouTube demonstration of the technique prior to attempting it myself. Perhaps I will remember that the next time I attempt something. Knowing me, I will not.

Varroa destructor, Varroa mite, is a common parasite of the honeybee. I’m not going to post any pictures because I think they’re pretty icky looking. Wikipedia has a good close-up image though, if you’re curious. This particular mite is a vector of multiple viruses that are passed to infested honeybee colonies. Serious infestations can result in death of the colony unless beekeepers step in with a variety of tools to protect their bees. The mite is native to Asia and so European honeybees, the most common honeybee in North America, have not evolved with this parasite and do not have adequate defenses against it. Beekeepers breed queens from selected stock with genetics that are more resistant to the mite, mainly through increased cleaning behaviors that are more likely to remove the mites. Africanized colonies are also thought to be more resistant to this threat. From what I’ve read, the mite is found throughout the United States. There is a citizen science project, Mite-A-Thon, to track mite levels across North America, but it is dependent on voluntary participation so a high reported mite level could mean that mite levels in the area are higher than other areas, but it could also mean that there is a high level of participation in the area.

There are a few methods to determine the mite level in a colony: alcohol wash, sugar roll, and a sticky board. The sticky board is a passive method that requires a layer of some sticky substance on a board placed under the hive. After three days, one looks at the board and counts the number of mites. This is not the most accurate method to use because it depends on the mites falling off or being cleaned off the bees for them to then land on the sticky board to be counted. The other two methods count the mites actually found on the bees. The alcohol wash is likely the most accurate, but it also kills all the bees used in the sample since they are swirled in alcohol to remove the mites, and then the mites are counted in the alcohol. The sugar roll is a similar method where the bees survive since they are only swirled in powdered sugar and can survive this level of abuse. So that was my preferred choice. Both the alcohol and sugar methods require collection of a sample of approximately 300 bees from different frames in the hive. Ideally the sample is composed primarily of nurse bees from the brood combs as these are the youngest bees and most likely to have mites since the mites attach to baby bees in the brood cells and emerge with the newly hatched bees already attached to them. The video is a great demonstration of how not to collect bees.

Besides my troubles with collecting bees, I also missed a key step in the method. After coating them, I was supposed to let the bees sit for a couple minutes to give them time to heat up in response to the sugar, which then causes the mites to release from the bees. You’ll see in the video my other error.

So after all that, the answer is that I still do not know if I have a mite problem or not. It has been so cold lately that I haven’t felt like disturbing them again so I may wait until spring to try again. Plus, I need to find a finer mesh screen to use that keeps the bees safely inside. My hope is that I won’t have a large mite problem yet since the colony was so small to begin with and I started with a queen known to have more hygienic behavior who will pass that on to some of her offspring. This may be wishful thinking.

I’ll leave you with a photo of my favorite assistant doing what he does best: enjoying the sun. I love this guy more than words can ever begin to express. He’s snoozing next to me now as I type this, hogging the entire chaise lounge and leaving only a small section of the sofa for Marc and I to share.

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