Although it is believed to be confined to the tropical and subtropical regions of Asia, the Asian parasitic brood mite, Tropilaelaps clareae, is a pest that has many beekeepers on edge. It is one of the parasites specifically mentioned in the Honeybee Act of 1922 and it is considered to be more menacing than Varroa destructor.
The mite is native to Asia and its natural host is the large Asian honey bee, Apis dorsata. However, in some regions such as Pakistan, it is found on many Apis species, including Apis mellifera. It is particularly prominent in warm areas where brood is raised throughout the year.
In many ways the Asian parasitic brood mite is similar to the Varroa mite. It is large and reddish brown and can be seen adhering to brood. In contrast to Varroa, however, this mite is longer than it is wide and runs quickly across the comb.
The female foundress mite enters a brood cell at the larval stage just before it is capped. There she lays about four eggs. These hatch and feed on the honey bee pupa, which causes malformations and/or death of the host. Complete development of the mite takes only about a week. It is this short development time that has beekeepers worried: populations can build up much more quickly than can populations of Varroa mites.
Evidence of Asian parasitic brood mites includes an irregular brood pattern and young bees with misshapen abdomens, irregular wings, and distorted or missing legs. The hapless newborn bees are frequently seen crawling at the entrance or along the top bars.
For the moment, control of Tropilaelaps is similar to control of Varroa. But considering our limited success at controlling Varroa, we should definitely be worried. At present Tropilaelaps does not thrive in regions that have periods of depressed brood rearing such as occurs in northern climates, but creatures with short life cycles evolve quickly, so we must consider Tropilaelaps to be a potential threat.