The Classroom
The Classroom – November 2024
Q: To treat or not to treat?
On August 8, I did a mite wash on my hives, one of which had a mite count of 15. On August 10, I treated with Formic Pro and today, September 4, I did another mite wash on that hive. It had a mite count of 5, but no brood at all. I saw the queen on the first mite wash and made sure she was safe. Is there any point in treating if there is no indication of a queen?
Dave Daiute
Massachusetts, September
A
I would not be so sure that the queen is absent. One of the potential side effects of treating with formic acid is that queens can stop laying or colonies can abort brood. It is possible, then, that this is just the colony’s response to treatment with formic acid. It is also possible that the queen is dead. If this is the case, the colony should have initiated the process to replace the queen. You should see queen cells or a virgin queen in the nest. Let us assume you had a queen on 10 August and that she died shortly after you worked your hive, which would represent the maximum amount of time the colony was queenless before your next inspection on 4 September. That is roughly a four-week period. During that time, the colony could have made a new queen (~2 weeks) and the new queen mated (~2 weeks). You, then, should have seen at least a few eggs when you worked the hive on 4 September. It is also possible that the queen died closer to your most recent visit (close to 4 September). In that case, you should have at least seen queen cells present in the nest as the bees worked to requeen themselves. If they went queenless on you, your colonies should be near the end of the requeening process (if she died right after 10 August) or at the beginning (if she died close to 4 September). My point is that you likely have a virgin queen running around in the nest, about to lay within the next week.
Your question, though, is, “Is there any point in treating if there is no indication of a queen?” First, I would follow the product label. Some treatments are labeled to occur in series, with treatments administered so many days apart. If that is the case for this treatment, then you would treat as instructed. If, though, there is a “queen clause” (i.e., do not treat in the absence of a queen) or if the label allows you to forego or delay a follow-up treatment, then I would not treat until the colony is requeened and brood is present in the nest.
Q: What to do with old pollen
A friend asked me this question: Older frames with some really old pollen, bees will not touch it, what should I do with it? I suggested soaking it in water a few days, washing it out with a garden hose and letting it dry. Maybe the bees will use it after this. How would you make use of old pollen bees are unwilling to use?
Bob Limbird
Arkansas, August
A
If the bees do not use it, there is not much you can do with it. I would do exactly what you suggest, except that I would try to spray it out with a garden hose before soaking it as it might wash out without soaking. Honestly, though, I tend to put frames like this back into a hive to see if the colony will clean it out themselves. If the colony does not clean it, then I might go the garden hose route. If enough old pollen washes out of the comb, you could just put it into your compost pile.
Q: Queen Feces
I was reading Dr. Collison’s master beekeeping study guide “What Do You Know,” which had a question as to whether virgin queens emit a pheromone that repels other workers and queens. The answer was “true,” so I had to look it up. I found a synopsis of a study that says a virgin queen’s feces contain a pheromone that repels workers and other queens. The pheromone in the feces causes the workers to groom themselves. The synopsis says, “Bioassays of virgin queen fecal material demonstrated that it contains pheromone that repels workers and stimulates grooming behavior. Pheromone was present only in the feces of virgin queens that were more than 24 hr old and less than 2 weeks old. Feces of 2- to 4-day-old workers and virgin queens more than 2 weeks old did not elicit an avoidance response by workers. Moreover, the feces of young virgin queens had a strong fragrance, while that of older queens had a rancid odor and that of young workers had no detectable odor.”
This was from the Journal of Chemical Ecology [source provided].
Unfortunately, it is an article that I cannot access due to it not being open source. Can you tell me a little bit more about this study? I am not sure if it is only expressed in Italian bees. Also, I am assuming this was done in a laboratory or observation hive. I am not sure if it is transferable to a full-size colony. I have never seen this since hives will kill virgins if they are not hopelessly queenless.
Regina Rhoa
Pennsylvania, August
A
I did find the study you note. The full reference for this study is: Post, D.C., Page Jr., R.E., Erickson Jr., E.H. 1987. Honeybee (Apis mellifera L.) queen feces: source of a pheromone that repels worker bees. Journal of Chemical Ecology, 13: 583 – 591. https://www.doi.org/10.1007/BF01880101.
I was able to download the article and I will tell you a little about what the authors did. First, all the research was conducted in the laboratory. The queens used in the study were reared according to standard queen rearing protocols. The workers used in the study were collected from test colonies. The queens and workers were brought into the laboratory and fed various diets (sugar candy, royal jelly, etc.). The workers were put into cups in groups of 10. Then, one of the test queens was placed in a cup with the workers to see the worker response to the queen and vice versa. The observer watched the queens for 5 minutes after introduction. About 30 minutes to 6 hours after this, a virgin queen was moved from one cup and placed into a second cup that already had its own queen. The observer then monitored interactions between the newly introduced queen and the one already present in the cup, and between the queens and workers in the cup.
The authors followed this with a study on how queens use feces. Here, 10 workers were placed into a single cup and exposed to feces of a test queen or another worker. The observer recorded worker behavior 60 seconds before and 60 seconds after exposure to the feces, recording one of three test behaviors.
In short, the study authors said that virgin queens, when introduced into the cups with workers, would offer a clear liquid from their mandibles to the workers. The workers, in turn, would take that liquid. If any workers showed antagonism to the queen, the queen would release liquid from the hindgut (mostly likely feces), causing the workers to move away from the queen. Two virgin queens exposed to one another released the hindgut material (again, most likely feces) on each other while fighting. Workers exposed to the fecal material would move away from it and begin grooming.
This research led the authors to suggest that the fecal material contains a pheromone that repels workers and stimulates grooming behavior. Queen feces have an odor that changes as the queens age. The authors noted “only feces of young queens that had a strong floral fragrance elicited avoidance behavior by bees.” At the time, the authors speculated how queens may use feces, or the pheromone they posited it to contain, in other settings: in the colony, at drone congregation areas, kin recognition, etc. The pheromone was not identified at the time.
Just for your information: There are ways that you can learn more about this topic. Most journals (in this case, the Journal of Chemical Ecology) list on the article page other articles in which the original article was cited. You can look at those articles to see how the science related to this topic has changed. You can also go to Google Scholar and enter the name of the article in the search box. Once done, you will see the article in the list of options. You will notice, if you do this, that Google Scholar says this article has been “Cited by 28.” This means that 28 other papers reference this one. Chase down those references (which you can do by clicking on “Cited by 28”) and you can see how the science on this topic has matured. This is a fantastic way to do additional investigative sleuthing on a topic …
