The mite Varroa destructor is an economically devastating ectoparasite of the Western Honeybee (Apis mellifera). It was originally known only from Apis cerana (which is found in southern and eastern Asia), but expanded its host range to include A. mellifera during the first half of the 20th century, spreading rapidly around the world, and is currently considered the single greatest threat to apiculture. Varroa mites have been considered a problem for beekeeping since around the late 1960s; by the 1970s, they had reached Western Europe and South America and by the 1980s they had reached the United States. On A. cerana, both V. jacobsoni and V. destructor apparently only parasitize drone (i.e., male) brood, whereas, for unknown reasons, the two mtDNA lineages of V. destructor that are capable of reproducing on A. mellifera utilize both drone and worker brood. (Rosenkranz et al. 2010 and references therein) Today, it can be safely assumed that all honey bee colonies within the mite’s range harbor varroa mites. As a consequence of mite infestation, dramatic colony losses have repeatedly occurred in affected countries (vanEngelsdorp and Meixner 2010 and references therein).