Tropilaelaps mites originally come from the tropical and subtropical regions of Asia. They are originally parasites of several honey bee species native to Asia. The two mite species T. mercedesae and T. clarae have extended their host range to the western honey bee Apis mellifera.

On all continents where the western honey bee occurs. For Europe, the occurrence of T. mercedesae was detected in the eastern Black Sea region from 2021. Tropilaelaps mites are not yet present in Austria or the EU.

Infested bee colonies with brood. Tropilaelaps mites can feed and multiply in brooding bee colonies. According to current knowledge, their ability to survive on adult bees and in colonies without brood is limited to a few days.

Tropilaelaps mites multiply in the capped bee brood and leave the cell when the bee hatches. They then linger briefly on combs and adult bees and again actively invade a brood cell that is about to be capped. Transmission from colony to colony occurs either naturally by bees flying away with Tropilaelaps mites on them or through beekeeping work, when infested brood combs or bees are transferred to other colonies.

Due to the rapid reproduction dynamics, damage can occur a few weeks or months after the initial infestation and a colony of the Western honey bee can die off after just one year of infestation.

Adult Tropilaelaps mites are approx. 1 x 0.5 mm in size, reddish-brown in colour and move rapidly around the hive. In an infested brood cell, the adult mite and its offspring suck on the bee pupa, damaging it. Clinical symptoms are bees with malformed or missing wings and legs, flightless crawlers, incomplete brood nest and dead brood. The damage caused by Tropilaelaps mites is similar to that of the Varroa mite.

Control is possible using biotechnical methods (brood interruption), as Tropilaelaps mites can only survive in colonies with brood. Varroa control agents are also used in Asia.

No movement of bees from distribution areas

Tropilaelaps mites do not currently occur in Austria.

Mites can be discovered on the combs when inspecting the colony. In contrast to Varroa mites, Tropilaelaps mites move quickly across the combs. Checking capped brood cells reveals possible brood infestation. The natural infestation can be checked by means of a mixture diagnosis.