English adaptation of the Turkish article, updated to include research published in 2026. Read the original Turkish article.
Recent studies suggest that the honey bee mite Tropilaelaps mercedesae can increase rapidly in infested colonies. Two complementary approaches have attracted research attention: deliberate brood interruption, which exploits the mite’s dependence on developing brood, and carefully timed formic-acid treatments. Research on early detection and swarming also shows why surveillance and management at the apiary level are essential.
Varroa destructor has long been among the most serious parasites in Turkish beekeeping. Tropilaelaps mites now pose another concern as their geographical range expands. However, it is important to distinguish evidence from experimental studies involving T. mercedesae from reports in which the species was not identified.
Official reporting of Tropilaelaps in Türkiye
In an announcement dated 14 August 2026, Apimondia referred to mites consistent with Tropilaelaps observed in a honey bee colony in the Artvin region on 26 July 2026. An occurrence was subsequently reported to the World Animal Health Information System (WAHIS) on 31 August 2026. The United Kingdom imposed temporary import restrictions on specified bees, apiculture by-products, used beekeeping equipment, and certain comb products originating from Türkiye from 4 September 2026.
The official report used the designation Tropilaelaps spp. This does not, by itself, establish that the mite in Türkiye was confirmed to be T. mercedesae. Species-level identification and appropriate surveillance remain important.
A parasite capable of rapid population growth
T. mercedesae reproduces in honey bee brood cells. A reproductive female enters a cell shortly before it is capped and can feed and reproduce on the developing host, damaging larvae and pupae. Tokach and colleagues (2024) investigated cultural and chemical control under experimental conditions in Thailand.
The proportion of infested brood cells in untreated control colonies increased from 0.40% to 15.25% over 60 days. The results illustrate how low initial infestation levels may grow dramatically in a relatively short period. This is one reason why early diagnosis and timely monitoring deserve priority.
New findings on early detection
Schouten and colleagues (2026) compared six methods of detecting Tropilaelaps in 27 infested Apis mellifera colonies in Papua New Guinea. Environmental DNA (eDNA) analysis detected mite presence in 100% of the infested colonies examined, while acaricide-assisted sticky boards showed 92% detection sensitivity. Alcohol washing yielded 41%, and the brood-frame bump method 33%. Rapid inspection of opened brood cells was identified as a relatively inexpensive method.
A separate study by Tokach and colleagues (2026) also found higher detection sensitivity with sticky boards, capped worker-brood inspection and brood-frame bumping than with conventional adult-bee alcohol-wash or powdered-sugar approaches.
Practical interpretation: A monitoring technique effective for Varroa cannot automatically be assumed to be equally sensitive for Tropilaelaps. The percentages above are study-specific estimates, not universal performance guarantees for every apiary.
Can natural swarming spread Tropilaelaps?
Uzunov and colleagues (2026) described a natural swarm in Georgia that transported eight female T. mercedesae mites. Four entered the first capped brood cells in the new colony and two reproduced successfully. This directly illustrates a possible pathway for dispersal and subsequent establishment.
Monitoring should therefore consider natural swarms in addition to managed colony movements, migratory beekeeping, and the trade in bees or beekeeping materials.
An important biological vulnerability: dependence on brood
Unlike Varroa, Tropilaelaps has a limited ability to feed for prolonged periods on adult honey bees. In the conditions examined by Tokach and colleagues, mites without access to suitable larvae approximately 3.5 days old or older could die within three days or less.
Once egg laying resumes in a broodless colony, it still takes about 6.5 days for newly laid eggs to develop into larvae suitable for mite feeding. This creates a potentially important interval during which the parasite may be unable to obtain a brood-based food source.
The 24-day queen-caging experiment
In the Thailand study, 51 queenright A. mellifera colonies were allocated to untreated controls, brood interruption alone, brood interruption combined with formic acid, and brood interruption combined with oxalic acid. The experimental queen-caging devices measured approximately 80 × 33 × 12 mm and were placed within brood frames near the center of the brood nest.
The queens remained caged for 24 days, after which they were released. At the time of release, sealed worker brood was no longer present in the brood-interruption groups. This approach temporarily removes the brood-cell environment needed for mite reproduction.
Brood interruption substantially reduced infestation
By day 60, brood infestation in untreated controls had reached 15.25%. In contrast, it was approximately 0.10% in the brood-interruption-only group and 0.11% in the brood-interruption-plus-oxalic-acid group. No mites were detected in the sampled capped worker-brood cells of the brood-interruption-plus-formic-acid group at that observation point.
Sticky-board data supported the same pattern: estimated daily mite fall in control colonies was around 15.48 mites per 24 hours, compared with fewer than 0.2 mites per 24 hours in treated groups.
However, a strong reduction in detectable mites must not be interpreted as proof of complete eradication. Very small surviving populations, reinfestation, and the limits of the sampling procedure all matter. The findings support a coordinated apiary-level approach rather than reliance on a single treatment of an isolated hive.
The 2026 Georgia field study: why treatment timing matters
A study by Janashia and colleagues published in Veterinary Parasitology in 2026 evaluated seasonal differences in the effects of formic-acid treatments against T. mercedesae and V. destructor in western Georgia. The colonies were managed in modified Dadant hives, with experiments conducted during August and October 2025.
The researchers compared two formic-acid products, Formic Pro® and Muraviinka®, and investigated mite mortality, including mites associated with capped brood. This is important because many contact-based treatments do not adequately reach mites protected inside sealed brood cells.
High Tropilaelaps sensitivity to formic acid
Both products produced rapid, very high T. mercedesae mortality in the experimental conditions. During the August trial, Formic Pro reached approximately complete observed mortality in about 2.5 days, while Muraviinka required roughly 2.5–5 days. During the October trial, both approaches produced near-complete mortality in approximately 2.5 days.
The study also found a strong decline in infestation within brood cells. The results are consistent with the ability of volatile formic acid to reach mites in the brood environment. Nevertheless, these outcomes are specific to the tested products, doses, application conditions, colony state, and seasonal temperatures.
Varroa did not respond identically
The response of V. destructor was more variable and appeared more dependent on season and brood stage. An appreciable increase in Varroa mortality was especially evident during the cooler October conditions, but results were not equivalent to those for Tropilaelaps. The survival of Varroa in younger brood stages also differed between treatment conditions.
An important lesson is that an application effective against one mite species cannot be assumed to be equally effective against the other, even when both parasites are present in the same colony.
Do beekeepers still need a 24-day brood interruption?
The two research lines examine different mechanisms. Queen caging interrupts the production of suitable brood and therefore the parasite’s reproductive cycle; formic acid can affect mites even when capped brood is present. Neither approach automatically replaces the other in all conditions.
A combination of biological brood management, surveillance and appropriately authorized chemical measures may be worth evaluating as part of integrated pest management. This is a research-based interpretation, not an officially validated treatment protocol for Türkiye. Regional validation, product authorization, and expert oversight remain necessary.
Temperature and colony safety are critical
High efficacy does not mean that formic acid is risk-free. In the Thailand experiment, temperatures above approximately 30°C were associated with reductions in adult bee populations in colonies receiving brood interruption and formic acid. The Georgian work also highlights the importance of season, weather, colony strength and product-specific conditions.
The summer climate of Artvin and the eastern Black Sea region differs markedly from that of Thrace, the Aegean, the Mediterranean or southeastern Türkiye. Beekeepers should therefore not directly transfer foreign experimental regimens into local practice or improvise formic-acid dispensers. Only legally permitted products and label-specific directions should be used under appropriate guidance.
Reinfestation and the movement of bees
The continuing or renewed detection of mites after intensive control raises an essential practical issue: treatment of an individual colony cannot prevent reinfestation from surrounding colonies, drifting bees or swarms. Movement controls, official reporting, and coordinated surveillance become particularly important in newly affected areas.
If an unfamiliar mite is suspected, its identity should be checked through the appropriate veterinary or agricultural authorities. Moving potentially infested colonies before assessment may complicate surveillance and containment.
What should Türkiye prioritize?
- Rapid recognition of suspicious mites, appropriate laboratory identification and official reporting.
- Monitoring approaches validated specifically for Tropilaelaps, including brood-focused inspections where appropriate.
- Surveillance of colony, swarm and equipment movement in areas at risk.
- Field research on brood interruption and legally authorized products under different Turkish climates.
- Long-term monitoring for reinfestation and assessment at the whole-apiary level.
Conclusion
Tropilaelaps mites can reproduce rapidly, yet their strong dependence on brood and susceptibility to some formic-acid treatments may offer opportunities for control. Research from Thailand and Georgia has established a scientific foundation, while newer monitoring and swarming studies clarify how easily infestation may be overlooked or spread.
For Türkiye, the priority is not to copy a single treatment used elsewhere, but to combine accurate detection, surveillance, coordinated biosecurity and locally validated integrated management. The 2026 official report makes these needs more urgent.
Scientific references
Tokach, R., Chuttong, B., Aurell, D., Panyaraksa, L., & Williams, G. R. (2024). Managing the parasitic honey bee mite Tropilaelaps mercedesae through combined cultural and chemical control methods. Scientific Reports, 14, 25677.
Janashia, I., Kovačić, M., Wilson, G., Uzunov, A., Costa, C., Chen, C., & Gill, M. C. (2026). Timing matters: Seasonal variations in the efficacy of formic acid treatments against the honey bee parasites Tropilaelaps mercedesae and Varroa destructor in the Caucasus. Veterinary Parasitology, 345, 110771.
Schouten, C. N., et al. (2026). Evaluation of methods for early detection of Tropilaelaps mites in European honey bee (Apis mellifera) colonies. Scientific Reports, 16, 22309. https://doi.org/10.1038/s41598-026-52776-1
Tokach, R., et al. (2026). Sensitivity of current Tropilaelaps mercedesae monitoring methods in Apis mellifera colonies. Scientific Reports, 16, 16778. https://doi.org/10.1038/s41598-026-46467-0
Uzunov, A., et al. (2026). Swarming promotes Tropilaelaps mercedesae dispersal in Apis mellifera. Journal of Economic Entomology, 119(2), 1473–1477. https://doi.org/10.1093/jee/toag027
Official context: World Animal Health Information System (WAHIS); United Kingdom Department for Environment, Food & Rural Affairs (Defra) notice of 3 September 2026 relating to Türkiye.
Original Turkish article: Türkiye arıcılığı için yeni alarm: Tropilaelaps akarına karşı bilim ne öneriyor?
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