The Classroom
The Classroom – December 2025
Q: Composition of bee venom
Do you think the winter bee biological/chemical makeup makes the stings more potent? Are the stings’ chemical makeup stronger because of the biological makeup helping bees live six months instead of 41 days? Have there been any studies? I think that there would be a simple chemical breakdown at different times of the year.
Ray Johnson
New Jersey, October
A
I found a study comparing winter and summer honey bee venoms. That paper was published by Danneels et al. in 2015.
Danneels, E.L., Van Vaerenbergh, M., Debyser, G., Devreese, B., De Graaf, D.C. 2015. Honeybee venom proteome profile of queens and winter bees as determined by a mass spectrometric approach. Toxins, 7(11): 4468-4483. https://doi.org/10.3390/toxins7114468.
The authors concluded that the compounds found in winter bee venom were also present in summer bee venom, but winter bee venom did lack compounds found in summer bee venom (vitellogenin, for example). The authors did not speculate about the potency of the venom (by “potency,” I assume you mean how much the sting would impact the individual stung). They only noted that there were some compounds absent in winter bee venom that were present in summer bee venom.
I used Google Scholar to find another five or so papers about seasonal differences in venom composition, but most authors noted differences without offering much discussion about how impactful a sting would be to the victim if stung by bees in summer or winter. In conclusion, there do appear to be differences in summer and winter bee venom composition, but the relevance of these differences to overall potency of the sting seems unknown.
Q: Cycling out old brood comb
In Tina Sebestyen’s September 2025 article “The Dark Side,” she referenced a very interesting article in Entomologia Experimentalis et Applicata to cast her argument to cycle out old brood foundation. Two things are highlighted by Sebestyen from this article experiment:
- Shortened brood cells before having newly hatched grafted larvae placed into them were invaded by mites either 2-3 times more or 1.5-2 times more than normal control cells for worker and drone cells, respectively.
- When a shortened distance of cell rim to larva occurred, foundress mites were more attracted for a longer period of time, 6-10 hours longer for worker cells and 12-14 hours longer for drone cells.
My questions are as follows: First, why, and how were the brood cells shortened? Does this occur in a normal beehive located in a beekeeper’s apiary? Second, for the test results to indicate a preference of worker brood over drone brood seems opposite to what we have been taught, that mites prefer drone brood over worker brood. What are we to conclude from this?
Third, and last, could there be other factors in this scenario causing this attractiveness to brood cells by Varroa mites? Is this possibly a limited study with just the two factors emphasized or are there other studies that verify the importance of these two factors? As a side note, I am intrigued by the fact that prepupa feces are enveloped in spun cocoons during the metamorphosis to the pupal stage, adhering to cell walls, and whether this results in giving an odor that help mites in any way be attracted to brood cells.
Bruce Snavely
October
A
I found the article in question (Boot et al., 1995) and read about how the authors shortened the brood cells. They used a hot knife to reduce the total length of the brood cells so that they could evaluate the hypothesis that the distance between the cell rim and the larva it contains is responsible for mite invasion into the cell. I think the idea is that Varroa want to invade cells that contain larvae ready to pupate. These larvae have grown to fill the cell, making them closer to the cell rim than are larvae still developing. The authors speculated that this could be one way the mites know when it is time to invade the cell.
Your ask if cells shorten over time in hives. We know that cell walls thicken over time, thus reducing the total diameter of the cell. I imagine this same effect happens at the bottom of the cell as well. This thickening happens because of generations of brood reared in the cell depositing silk and general wax accumulation in the cell. I do not think that the study authors were making the argument that old combs have shallower cells, making Varroa infestations worse in those hives. Instead, they simply wanted to control the distance between the cell rim and the larva to see how that affects Varroa invasion.
I read the paper and Tina’s article and did not get the impression that either author was saying that Varroa preferred worker brood to drone brood. We have ample evidence in the literature that Varroa prefer drone brood.
Regarding cell invasion: Boot et al. (1995) were making the argument that Varroa use certain physical cues (distance of larva from cell rim) when deciding whether to invade a cell. This work was done when Varroa were becoming an international threat to honey bee health. Now, we know much more about Varroa invasion into cells. For example, Liu et al. (2023) and others clearly demonstrated Varroa attraction to volatiles produced by drone and worker larvae. This finding shows that Varroa cue into certain chemicals produced by developing bees. Indeed, chemical cues may be the main driver of Varroa invasion into brood cells.
Honey bee larvae create cocoon-like structures in their cells when they develop. This webbing can trap feces and other materials in the cell, making it difficult for adult worker bees to clean the cell. Of course, the odors produced by these materials may also attract Varroa, but more work is needed on this front. Nevertheless, the cocoon-like structures contribute to the shrinking cell diameter that occurs as generations of brood are reared in the cells.
Boot, W.J., Driessen, R.G., Calis, J.N.M., Beetsma, J. 1995. Further observations on the correlation between attractiveness of honey bee brood cells to Varroa jacobsoni and the distance from larva to cell rim. Entomologia Experimentalis et Applicata, 76(3): 223 – 232. https://doi.org/10.1111/j.1570-7458
.1995.tb01966.x.
Liu, J., Zhang, R., Tang, R., Zhang, Y., Guo, R., Xu, G., Chen, D., Huang, Z. Y., Chen, Y., Han, R., & Li, W. 2023. The role of honey bee derived aliphatic esters in the host-finding behavior of Varroa destructor. Insects, 14(1): 24. https://doi.org/10.3390/insects14010024.
Q: Honey bee pheromones
Having just read and re-read Allison McAfee’s “How a Colony Decides to Replace its Queen” makes me curious about what tools might become available to beekeepers that could ascertain pheromones present in a hive? Ms. McAfee’s use of such tools in research tells me there are such methods in the laboratory for scientists to explore the mysteries of the hive. I have asked this question of a couple scientists I know and have been told capturing pheromone molecules is a great challenge requiring extensive equipment and processes. It just seems that pheromones are the key to the language of the hive, and a handy-dandy little gadget would go far to understand what is going on in the hive. How is it done in the laboratory?
Gregg Caudell
October
A
You are correct. Pheromone usage represents an important way that honey bees communicate to one another inside and outside the hive. The scientists you queried are also correct. The process of capturing and analyzing pheromones is difficult and can be expensive.
Pheromones are chemicals that can be deposited onto surfaces or volatilized. Chemical ecologists use various strategies to collect pheromones. For example, they may wash a surface to collect pheromones deposited onto it. They may use special absorbent materials, such as SPME (solid phase microextraction) fibers, to collect pheromones that are volatilized. Once collected, the analyte (the pheromone in this example) is passed through an expensive machine (a high-performance liquid chromatography machine if a liquid, and a gas chromatography-mass spectrometry machine if a gas) that will characterize the compound(s) present. This can be used to determine the chemical composition of a particular pheromone.
From there, other scientists attempt to determine how the organism uses the pheromone. You must attach the pheromone to a behavioral or physiological change in the organism receiving the pheromone. Simply knowing its chemical composition is not enough to determine the importance of the pheromone to the honey bee. This can take a lot of time, money, supplies, reagents, etc. It is not really feasible at the beekeeping scale currently.
Of course, I am a believer in science and the ability of humans to solve problems. While doing what you suggest is not financially or practically feasible today, it certainly could be in the future. Machine learning, rapidly advancing technologies, and the affordability of analytical capacity may make doing what you propose possible in the future. I know scientists who are conducting similar work with sounds that honey bees produce. It would be nice to be able to put a microphone and chemical analyzer next to a hive and know what the bees are saying. Imagine the management decisions we could make if we could decipher a colony’s language in real time …
