1. The essentials in brief

• Queen ringing aims to interrupt laying without confining the queen: a small tube placed on the abdomen prevents proper egg-laying while still allowing the queen to move about in the hive.
• The practical objective is close to that of queen caging: to obtain a broodless period so that an oxalic acid treatment becomes more effective against phoretic varroa mites.
• The only published experimental trial on summer queen ringing remains modest: 21 colonies in Beijing, of which 7 ringed, 7 caged and 7 controls.
• In this trial, queen ringing did not significantly reduce colony development, but a queen problem appeared in 2 of the 7 ringed colonies.
• Winter use, often presented as the method's main appeal, remains to date insufficiently documented to make it an established recommendation in Switzerland.

2. What the study shows

Two publications describe queen ringing: one presents the method, the other compares it with queen caging in a small summer trial in China.

 

Fig.: Placement of the device on the queen. On the left, the forceps used by the researchers.

Question. Queen caging is a known method for inducing an interruption of laying. It makes oxalic acid treatments more effective when the colony becomes temporarily free of capped brood. But caging immobilises the queen, which can be a problem, especially in winter, when the cluster moves about in the hive. The authors therefore study an alternative used in China: queen ringing.

Method. The first article, published in Bee World in 2023, describes the device and how it is fitted. It is a small split, slightly conical plastic tube placed around the front part of the queen's abdomen. The wide opening measures about 5.8 mm in diameter and the narrow opening, positioned towards the petiole, about 3 × 2 mm. The tube prevents the queen from positioning her abdomen correctly to lay eggs at the bottom of the cells, but must not block her legs or wings. The authors stress the quality of the material, the absence of sharp edges and the need to practise before fitting the tube on a queen.

The second article, published in 2024 in the Journal of Apicultural Research, compares ringing with caging. The trial was conducted in Beijing from June to October 2023, during the summer flow of Vitex negundo and scattered flowers. Twenty-one Langstroth colonies, run with one-year-old queens from a local stock of Apis mellifera ligustica, were divided into three groups of seven: a control group with no interruption of laying, a group with a caged queen and a group with a ringed queen. The queens were caged or ringed on 28 June, then released 25 days later, on 23 July. A trickling treatment with 4.2% oxalic acid was applied at the time of release.

Results. The authors observed no statistically significant difference between the groups in colony strength, measured in frames covered by bees and in brood frames. The colonies with an interruption of laying thus partly compensated for the temporary stop in laying. The control colonies nonetheless tended to be slightly stronger, which is to be expected when a colony rears brood without interruption.

The honey harvest was higher in the two groups with an interruption of laying than in the control group. The reported means are 9.3 kg for the controls, 12.8 kg for the ringed colonies and 13.1 kg for the caged colonies. The authors interpret this result as the possible consequence of a lower expenditure on brood rearing for about three weeks. It should not, however, be turned into a general rule: this result depends on the local timing of the flow and on the trial context.

The most sensitive point concerns the queens. In the ringed group, one queen was lost after release and another coexisted with a daughter at the final inspection. The authors rule out an effect of age, since all the queens were one year old, and suggest instead an injury during removal of the tube or during the wearing period. Eggs, larvae and queen cells were also observed in some groups where the queen's laying was supposed to be blocked. The arrangement of the eggs suggests laying workers, but the authors consider the exact origin to remain uncertain.

Interpretation. The authors present queen ringing as a promising alternative to caging for inducing a summer interruption of laying. Their trial shows above all that, under the conditions studied, ringing did not lead to a measurable loss of colony development compared with caging. It does not directly demonstrate efficacy against varroa, since the trial measures neither mite mortality nor the evolution of the infestation. The authors themselves stress the need for larger studies, in particular on queen health, winter use, possible injuries and the effect in different beekeeping environments.

3. A critical look

The idea is biologically plausible, but the direct data on queen ringing are still too limited for a rapid transposition to the Swiss apiary.

Strengths. The 2024 study compares three clearly defined groups: control, caging and ringing. The colonies were balanced at the outset according to their strength, and the parameters observed are relevant to beekeeping: colony development, queen survival and performance, queen cells and honey production. The comparison with caging is useful, because caging is today the reference method when one wants to induce an interruption of laying without destroying all the brood.

Limitations. The trial remains very small: 21 colonies in total, i.e. 7 per group. It takes place over a single season, in a single experimental apiary, with a local bee of the ligustica type and in a flow and swarming context specific to the Beijing region. The method is tested only in summer. Yet one of the main arguments in favour of ringing concerns precisely the winter, since the queen could continue to follow the cluster, unlike a caged queen.

Possible biases and confounding factors. The swarming period in the study region complicates the interpretation of the queen cells observed. Honey production depends strongly on the timing of the flow, the initial state of the colonies and local resources. The available publications also come from the same network of authors, which is not in itself a problem but calls for independent replications.

What cannot be concluded. One cannot conclude that ringing controls varroa as well as caging, since the 2024 trial does not directly measure acaricidal efficacy. Nor can one conclude that the method is safe for queens on a large scale: in the small ringed group, two queen incidents out of seven deserve attention. Finally, winter use is not demonstrated by peer-reviewed results.

Transposition to the Swiss and temperate European apiary. The general principle — temporarily rendering the colony broodless in order to reach the phoretic varroa mites more effectively — is well known and consistent with integrated varroa control strategies. The ringing device itself, however, remains to be evaluated under Swiss conditions: winter temperatures, cluster dynamics, the real duration of the interruption of laying, hive types, the ability to find the queen and the safety of removal. The status of the material and its possible compatibility with Swiss regulations, notably in organic beekeeping, must also be checked before any practical dissemination. 

4. What related studies show

The related studies support above all the principle of " brood interruption + adapted treatment ", but not yet solidly queen ringing itself.

The related literature is more solid on brood interruption than on ringing. The European study by Büchler et al. (2020), conducted on 370 colonies in 10 countries, compares several methods: queen caging, total brood removal and the trap comb. It shows that these methods can contribute effectively to varroa control when correctly combined with an adapted treatment, notably oxalic acid during a broodless period. This study is important for the European context, but it does not test ringing.

Gregorc et al. (2017) point in the same direction: brood removal or queen caging, combined with oxalic acid, reduce varroa populations. Gabel et al. (2023) provide mechanistic support: interruptions of laying affect the reproduction of Varroa destructor, notably by increasing the non-reproduction of the mites. This work therefore supports the general biological reasoning, without directly validating the ring tube.

Other studies call for nuance. Kovačić et al. (2023), in six Mediterranean countries, show that summer caging combined with oxalic acid can reduce infestation, but that the timing of application influences honey production. Bubnič et al. (2024), in Slovenia and Italy, report good acaricidal efficacy from caging or the trap comb followed by an oxalic acid treatment, but without a significant rapid decline in the viral loads measured after 25 days. In other words, reducing varroa mites does not necessarily mean immediately reducing the associated viruses.

Conversely, Jack et al. (2020), in a different, American context, constitute a note of caution. In their trial, brood interruption by caging and vaporised oxalic acid did not provide sufficient varroa control, and some treatments were associated with a decline in colony strength or survival. This result should not be transposed as such to Switzerland, but it is a reminder that efficacy depends on climate, timing, the presence of brood, the application method and the initial infestation level.

Concerning ringing itself, the data remain limited. The page of the COLOSS " Varroa control " Task Force mentions the effect of queen ringing on varroa infestation among the planned activities, and indicates that an analysis of the impact of brood interruption on colony health and productivity is under way. The article in La Santé de l’Abeille also mentions a larger study coordinated within COLOSS, with more than 25 partners and around 500 hives, on the basis of a personal communication. At the time of this synthesis, I have not found a scientific publication presenting these results. This point therefore remains to be followed.

In summary, the convergence is strong enough to say that a well-conducted brood interruption can be integrated into a varroa strategy. It is still insufficient to make ringing an established method. Ringing remains an interesting technical avenue, but its practical value will depend above all on forthcoming results on overwintering, queen injuries, the consumption of food stores and the real efficacy against varroa in different contexts.

5. What to take away at the apiary?

At the apiary, the solid message concerns first of all the control of the broodless period; ringing remains an emerging method.

• A genuine broodless period remains an important lever in varroa control, especially when using a treatment that acts mainly on the phoretic mites.
• Ringing may be interesting in theory, notably in winter, because the queen is not immobilised in a cage and could follow the cluster. But this hypothesis still has to be confirmed by results published under conditions close to those of Swiss apiaries.
• The method requires excellent dexterity. At this stage, it should be considered only on a very small scale, by experienced beekeepers, with careful monitoring of the queen and the possibility of replacing her in case of an accident.
• The possible gain in honey observed in the Chinese trial should not be sought as the main objective. It depends on the local timing of the flow and may be paid for by a temporary reduction in population dynamics.
• A brood interruption does not replace infestation monitoring. It must remain integrated into a complete varroa management concept: monitoring the infestation level, choosing the right moment, an authorised treatment, verification of efficacy and proper preparation for overwintering.

 

Read the original study

Review article: Kievits J., 2024. Le cerclage de la reine, une nouvelle méthode pour interrompre l’élevage du couvain. La Santé de l’Abeille, no. 324, pp. 25–29.

Original scientific publications: Uzunov A. & Chen C., 2023. Queen Ringing – An Alternative Method for Inducing Brood Interruption. Bee World, 100(3–4), 67–70.

 Uzunov A., Chen C., Gabel M. & Kovačić M., 2024. Queen ringing vs. queen caging for summer brood interruption. Journal of Apicultural Research, 63(4), 660–663.

 

Find out more:

• Practical Guide: 1.6.1 Brood break
• Practical Guide: 1.3.2. Trickling method
• Laying block: varroa control
• Varroa control: summer brood interruption
• Winter varroa treatment: what to do if the colonies are still rearing brood?

 

Bibliography

Kievits J., 2024. Le cerclage de la reine, une nouvelle méthode pour interrompre l’élevage du couvain. La Santé de l’Abeille, n°324, p. 25–29.

Uzunov A. & Chen C., 2023. Queen Ringing – An Alternative Method for Inducing Brood Interruption. Bee World, 100(3–4), 67–70. DOI : 10.1080/0005772X.2023.2263285.

Uzunov A., Chen C., Gabel M. & Kovačić M., 2024. Queen ringing vs. queen caging for summer brood interruption. Journal of Apicultural Research, 63(4), 660–663. DOI : 10.1080/00218839.2024.2354087.

Büchler R. et al., 2020. Summer brood interruption as integrated management strategy for effective Varroa control in Europe. Journal of Apicultural Research, 59(5), 764–773. DOI : 10.1080/00218839.2020.1793278.

Gregorc A., Alburaki M., Werle C., Knight P. R. & Adamczyk J., 2017. Brood removal or queen caging combined with oxalic acid treatment to control varroa mites (Varroa destructor) in honey bee colonies (Apis mellifera). Apidologie, 48, 821–832. DOI : 10.1007/s13592-017-0526-2.

Gabel M., Scheiner R. & Büchler R., 2023. Immediate and long-term effects of induced brood interruptions on the reproductive success of Varroa destructor. Apidologie, 54, 1–17.

Kovačić M. et al., 2023. Honey vs. Mite — A Trade-Off Strategy by Applying Summer Brood Interruption for Varroa destructor Control in the Mediterranean Region. Insects, 14(9), 751. DOI : 10.3390/insects14090751.

Bubnič J. et al., 2024. Integrated Pest Management Strategies to Control Varroa Mites and Their Effect on Viral Loads in Honey Bee Colonies. Insects, 15.

Jack C. J., van Santen E. & Ellis J. D., 2020. Evaluating the Efficacy of Oxalic Acid Vaporization and Brood Interruption in Controlling the Honey Bee Pest Varroa destructor. Journal of Economic Entomology, 113(2), 582–588. DOI : 10.1093/jee/toz358.

COLOSS, Varroa control Task Force. " Varroa control " web page, section on current and planned activities. Non-peer-reviewed source, consulted in 2026.

Note: the two articles by Uzunov and colleagues were consulted in full text. The other studies in chapter 4 were used with caution based on the bibliographic information and available abstracts.