Tropilaelaps: biology, detection and the threat to Europe

Key points

An Asian brood mite with a faster reproductive cycle than varroa.
Established in south-western Russia, confirmed in Georgia in 2024 and in Türkiye in 2026.
Smaller and more elongated than varroa, it runs fast across combs and survives only briefly away from brood.
Look for it in capped brood: washing adult bees detects it poorly.
Absent from the EU and notifiable: report any suspicion without delay.

Tropilaelaps is a parasitic mite of honey bee brood. It comes from Asia, where it originally lives on giant honey bees such as Apis dorsata. Having jumped to the western honey bee, Apis mellifera, it reproduces faster there than varroa and can devastate a colony within a single season. Specialists describe it as a major emerging threat to the European honey bee².

It is now moving westwards: established in south-western Russia, confirmed in Georgia in 2024, then in Türkiye in 2026. The European Union is still free of it. This page covers its biology, how to tell it apart from varroa, how to look for it in a hive and how to respond if in doubt.

Four species, two dangerous to the honey bee

Until 2007, most Tropilaelaps mites parasitising the honey bee were assigned to a single species, T. clareae. Anderson and Morgan’s genetic and morphological study showed that the genus contains at least four species¹:

T. mercedesae: described in 2007, it parasitises Apis dorsata in mainland Asia and most of Indonesia, as well as the honey bees introduced into those regions. It is the most widespread species and the one advancing towards Europe.
T. clareae: now more narrowly defined, it is restricted to the Philippines and the island of Sulawesi, where it also parasitises the honey bee.
T. koenigerum: found on giant honey bees, with no known importance for the western honey bee.
T. thaii: described in 2007 from the Himalayan giant honey bee, Apis laboriosa.

The original hosts are therefore the giant honey bees, A. dorsata and A. laboriosa¹. Only T. mercedesae and T. clareae are adapted to the western honey bee, and T. mercedesae is the main risk for Europe^{5, 9}. The species look alike: accurate identification requires molecular methods⁸.

Biology: a parasite entirely dependent on brood

A shorter cycle than varroa

Like varroa, the female enters a brood cell just before it is capped, but everything happens faster. According to the UK bee inspectorate, she lays her first egg about 10 hours after capping, then one egg every 24 hours; varroa lays its first egg after about 60 hours, then every 30 hours⁶. Development from egg to adult takes about six to nine days, depending on climate^{5, 6}.

The mites feed on the haemolymph of pupae; unlike varroa, they cannot pierce the cuticle of adult bees or feed on them⁸. Another difference: they show no clear preference for drone brood⁶, which makes drone brood trapping of little use.

Very short survival away from brood

The transport phase on adult bees is brief. The UK National Bee Unit gives survival of up to 3 days on adult bees, about 3 days on honey, pollen or candy, and up to 6 days on empty comb⁶. This is the key to control: a colony deprived of brood for long enough sees its mite population collapse.

Winter alone does not stop it, however: the parasite has become established in regions where a winter brood break is assumed to occur⁵.

How it spreads

Over short distances it travels on adult bees (drifting, robbing, swarms); over long distances, through trade in queens and colonies, migratory beekeeping and used equipment⁹. French authorities regard queen imports as the main possible route of entry into France¹⁰.

Why it is so dangerous

It multiplies very fast. Its short cycle lets it gain the upper hand over varroa when both mites share a colony. In the Krasnodar region of Russia, infestation reaches up to 75% of brood in September⁶.
It destroys brood. Parasitised pupae die or emerge as deformed bees; the colony weakens, absconds or dies^{2, 9}.
It transmits viruses, including deformed wing virus².
It comes on top of varroa. In Georgia, infested colonies also carried varroa, with high infestation rates and good Tropilaelaps reproductive success⁴.
It is hard to see and slips through routine varroa monitoring⁵.

Where is it in 2026?

Area	Situation	Source
South and South-East Asia	Native range; present on A. dorsata and on honey bees in many countries	²
China, Pakistan, Afghanistan, Papua New Guinea	Present on honey bees; possibly present in Iran	⁶
Russia (Krasnodar region)	Established populations; colonies affected from 2021	^{3, 8}
Georgia (Samegrelo-Zemo Svaneti)	Confirmed in 2024 on A. m. caucasica	⁴
Türkiye (Borçka area)	Detection confirmed by Turkish authorities on 31 August 2026, near the Georgian border	⁷
Uzbekistan, Tajikistan, Crimea, Belarus, Azerbaijan	Suspected reports, not officially confirmed	^{6, 9}
European Union	Free	^{9, 10}

Türkiye, with its large migratory beekeeping sector, is now affected. The situation changes quickly: check the latest updates from the French Plateforme ESA or the UK National Bee Unit^{5, 9}.

Identifying Tropilaelaps

Differences from varroa

Feature	Tropilaelaps (female)	Varroa destructor (female)
Size	About 1 mm long and 0.5 to 0.6 mm wide	About 1.1 mm long and 1.6 mm wide
Shape	Elongated, longer than wide	Crab-like, wider than long
Colour	Reddish-brown to light orange-brown	Dark reddish-brown
Movement	Very fast, runs across combs	Slow
On adult bees	Rarely, for a few days at most	Common, for several days
Preference for drone brood	Not clear	Strong

Sources: ^{6, 8}; for varroa, see the Varroa page.

Harmless pollen mites or the small, pale male varroa can cause confusion: only laboratory analysis is conclusive.

Photo needed — Side-by-side comparison, at the same scale, of a female varroa and a female Tropilaelaps on a white background, with a scale bar. Openly licensed image only.

Signs in the colony

The symptoms resemble those of a heavy varroa infestation⁸:

patchy, spotty brood with perforated cappings;
dead or malformed pupae, sometimes removed by workers and dumped in front of the hive;
young bees with stunted wings and shortened abdomens;
small elongated mites running over combs lifted from the hive;
rapid weakening, or even absconding of the colony.

None of these signs is specific: you need to find the mite itself.

Photo needed — Capped brood cells opened with forceps, showing white pupae with small elongated reddish-brown mites, taken in raking light with an illuminated magnifier.

Detection: step-by-step methods

Since the mite lives mainly in brood, that is where to look. Methods based on adult bees detect it poorly^{8, 11}.

Uncapping brood

This is the reference method.

Choose a frame of older capped brood, with pupae still white or lightly pigmented.
Shake off the bees.
Open a block of about 100 cells and remove each pupa⁶. Use fine forceps or depilatory wax strips rather than an uncapping fork, which damages the mites¹¹.
Examine pupae and cells with an illuminated magnifier and a head torch: the mite shows up as a small brown speck on the white pupa⁶.

The bump test

Hold a frame of capped brood over a white tray and give it a sharp knock. Any mites that fall run across the pale surface. The method is quick but not very sensitive: in a trial in Papua New Guinea, it detected the mite in only about a third of cases¹⁴.

Sticky boards

A board slid under a mesh floor collects falling mites. It needs to be checked often, under good light, because the mite blends into debris¹¹. In the Papua New Guinea trial, sticky mats combined with a 24-hour acaricide treatment detected the mite in 92% of cases¹⁴. In Europe, as no acaricide is authorised against Tropilaelaps, this approach is a matter for official services.

Alcohol wash and sugar roll

These varroa counting methods detect Tropilaelaps poorly: about 41% sensitivity for the alcohol wash in the trial cited¹⁴. But any unusual mite found during a count should be kept and reported⁶.

New methods

Swabs used to detect the mite’s DNA picked up Tropilaelaps in every infested colony in the trial, even at low levels, but cost more¹⁴. They are still a tool for research and official surveillance.

Laboratory analysis

Identification is done by an official laboratory. In France, the Anses national reference laboratory in Sophia-Antipolis confirms suspicions¹¹. Mites are sent killed by freezing or preserved in 70% alcohol, in a sealed tube, with the exact origin of the sample⁸.

Regulations

In the European Union, Tropilaelaps infestation is a disease regulated under the Animal Health Law, Regulation (EU) 2016/429, listed in categories D and E: measures to prevent its entry and spread through trade, and mandatory surveillance. Notification is mandatory. It is also listed by the World Organisation for Animal Health (WOAH)⁹.

In France, any suspicion must be reported without delay to the departmental veterinary services (DDPP or DDETSPP), to the single contact point of the bee mortality observatory (OMAA) in regions where it exists, or to a veterinarian^{9, 10}. Control measures fall under a ministerial order of 23 December 2009; in a confirmed infestation, the protocol provides for the destruction of affected colonies and apiaries, with compensation for beekeepers¹⁰.

Trade in bees. Imports of live bees from non-EU countries are tightly controlled: queens may only be imported from a restricted list of countries, with a declaration and a health certificate^{9, 11}. Movements between Member States are also subject to health rules.

Medicines. No veterinary medicine is authorised against Tropilaelaps in the European Union^{8, 11}.

Rules differ outside the EU (in the United Kingdom, for example, it is also notifiable⁵): check with the veterinary services in your country.

Control options under study

This research, carried out mainly in Thailand, sheds light on what might work in Europe, but does not amount to authorisation for use.

Brood breaks

This is the most logical lever, as the mite survives poorly without brood. A brood break can cut mite numbers by more than 90%, but populations recover within about two months: interventions therefore need to be more frequent than against varroa⁶.

Formic acid

Formic acid works under the cappings, where the mite lives, and has given consistent results⁶. In central Thailand, a team including Samuel Ramsey (University of Colorado Boulder) and the USDA Bee Research Laboratory compared formic acid with heat treatment. Both forms of formic acid tested brought live Tropilaelaps numbers down sharply within a week, while numbers rose in control colonies; heat treatment reduced them by about 85%. Some adult bee mortality was observed¹³.

Combined methods

A Thai study combined a brood break with oxalic or formic acid: over 60 days, infestation soared in untreated colonies and stayed very low in the others. However, no method eliminated every mite, which would not be enough to eradicate it from a mite-free country¹².

In practice: what beekeepers actually do

In Europe, the goal is to keep the mite out and to spot it early. In Asia, it is about living with it. Here are the practices that come up most often.

Getting ready in Europe

Learn to recognise it, with a comparison photo to hand, and attend the training offered by beekeeping health organisations.
Look at brood differently. During inspections, it is worth opening a few cells of older capped brood and following any tiny mite that runs across a comb.
Read sticky boards under good light, with a head torch, looking for elongated mites.
Watch for unusual pictures: badly damaged brood despite low varroa counts.

Buying bees safely

Buy queens, packages and colonies from identified suppliers, with a health certificate; refuse anything of uncertain origin.
Before importing yourself, contact the veterinary authorities to learn the procedure.
Avoid used beekeeping equipment of unknown origin.

If in doubt

Collect the mites with a fine moistened brush and place them in a sealed tube of alcohol, or freeze them.
Photograph the mite and note the hive, apiary and date.
Do not move colonies, frames or equipment.
Report the suspicion immediately to the veterinary authorities or your veterinarian.

What beekeepers do in Asia

Where the mite is established, studies mainly describe repeated brood breaks (queen caging, splits, nucs), often combined with formic acid^{6, 12, 13}. The principle: never leave the mite with brood long enough to multiply.

Useful equipment

Fine forceps or depilatory wax strips, an illuminated magnifier, a head torch, a white tray, sticky boards under a mesh floor and sealed tubes of 70% alcohol.

Checklist

I can tell Tropilaelaps from varroa.
My queens and colonies have a known origin and a certificate.
During the season, I regularly open some older capped brood.
I have alcohol tubes and my veterinary services’ contact details.

The most common mistakes

Assuming an alcohol wash is enough: it detects poorly a mite that lives mainly in brood.
Mistaking Tropilaelaps for a male varroa or a pollen mite, and not reporting it.
Opening brood with an uncapping fork: damaged mites become hard to identify.
Importing queens outside official channels, the main feared route of entry.
Moving colonies or equipment after a suspicion.
Treating with an unauthorised product yourself: this delays diagnosis and can mask the infestation.

Frequently asked questions

Do my varroa treatments also protect against Tropilaelaps? Not reliably. Synthetic acaricides are much less effective: amitraz, for example, had little or no effect in Thai trials⁶. No medicine is authorised against Tropilaelaps in the EU.

When could it reach Western Europe? Some experts think it could reach France within a few years. Its confirmation in Türkiye in 2026 brings the front closer to the EU’s borders.

I found an elongated mite on my sticky board: what should I do? Keep it in alcohol or in the freezer, photograph it and contact your veterinary authorities. Most of the time it will be a harmless mite, but only analysis can confirm this.

References

Anderson D.L., Morgan M.J. (2007). Genetic and morphological variation of bee-parasitic Tropilaelaps mites (Acari: Laelapidae): new and re-defined species. Experimental and Applied Acarology 43: 1-24. doi.org
Chantawannakul P., Ramsey S., vanEngelsdorp D., Khongphinitbunjong K., Phokasem P. (2018). Tropilaelaps mite: an emerging threat to European honey bee. Current Opinion in Insect Science 26: 69-75. doi.org
Brandorf A., Ivoilova M.M., Yañez O., Neumann P., Soroker V. (2024). First report of established mite populations, Tropilaelaps mercedesae, in Europe. Journal of Apicultural Research. doi.org
Janashia I., Uzunov A., Chen C., Costa C., Cilia G. (2024). First report on Tropilaelaps mercedesae presence in Georgia: the mite is heading westward! Journal of Apicultural Science 68(2): 183-188. doi.org
National Bee Unit (APHA, UK). Tropilaelaps: factsheet and distribution map (map current as of December 2025). nationalbeeunit.com
National Bee Unit (APHA, UK) (2026). Tropilaelaps, parasitic mite of honey bees. Advisory leaflet. nationalbeeunit.com
National Bee Unit (APHA, UK) (2026). Tropilaelaps discovered in the Republic of Türkiye. nationalbeeunit.com
IZSVe, Italian reference centre for beekeeping (2025). Acaro Tropilaelaps spp. (in Italian). izsvenezie.it
Plateforme ESA, Anses, DGAL (2025). Geographical spread of the exotic mite Tropilaelaps: international situation as of 31 July 2025 (in French). plateforme-esa.fr
French Senate. Written question no. 03991 and answer from the Ministry of Agriculture (JO Sénat, 15 May 2025) (in French). senat.fr
Franco S., Roy C., Barascou L., Vallon J. (2026). Habituez-vous à prononcer son nom : « Tropilaelaps ». Réussir Apiculture (in French). reussir.fr
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. doi.org
Sankovitz M., Steinhauer N., Yemor T., Cook S.C., Evans J.D., Ramsey S.D. (2025). Evaluation of efficacy of formic acid and thermal remediation for management of Tropilaelaps and Varroa mites in central Thailand. Journal of Apicultural Research 64(4): 1049-1058. doi.org
Schouten C.N., Lees K., Roberts J.M.K., Brewster E.T., Gabriel F., Tonny K. (2026). Evaluation of methods for early detection of Tropilaelaps mites in European honey bee (Apis mellifera) colonies. Scientific Reports 16: 22309. doi.org

Updated : October 8, 2026
Written by : Apisanitas editorial team
Reviewed by : Review in progress