Varroa jacobsoni (Acari: Varroidae) is more than one species

Abstract

Varroa jacobsoni was first described as a natural ectoparasitic mite of the Eastern honeybee (Apis cerana) throughout Asia. It later switched host to the Western honeybee (A. mellifera) and has now become a serious pest of that bee worldwide. The studies reported here on genotypic, phenotypic and reproductive variation among V. jacobsoni infesting A. cerana throughout Asia demonstrate that V. jacobsoni is a complex of at least two different species. In a new classification V. jacobsoni is here redefined as encompassing nine haplotypes (mites with distinct mtDNA CO-I gene sequences) that infest A. cerana in the Malaysia Indonesia region. Included is a Java haplotype, specimens of which were used to first describe V. jacobsoni at the beginning of this century. A new name, V. destructor n. sp., is given to six haplotypes that infest A. cerana on mainland Asia. Adult females of V. destructor are significantly larger and less spherical in shape than females of V. jacobsoni and they are also reproductively isolated from females of V. jacobsoni. The taxonomic positions of a further three unique haplotypes that infest A. cerana in the Philippines is uncertain and requires further study. Other studies reported here also show that only two of the 18 different haplotypes concealed within the complex of mites infesting A. cerana have become pests of A. mellifera worldwide. Both belong to V. destructor, and they are not V. jacobsoni. The most common is a Korea haplotype, so-called because it was also found parasitizing A. cerana in South Korea. It was identified on A. mellifera in Europe, the Middle East, Africa, Asia, and the Americas. Less common is a Japan/Thailand haplotype, so-called because it was also found parasitizing A. cerana in Japan and Thailand. It was identified on A. mellifera in Japan, Thailand and the Americas. Our results imply that the findings of past research on V. jacobsoni are applicable mostly to V. destructor. Our results will also influence quarantine protocols for bee mites, and may present new strategies for mite control.