2.4.4. Species identification

A 458 DNA base-pair fragment of varroa mtDNA cox1 gene has proved useful in identifying mites to a particular species (Anderson and Trueman, 2000). To do this, a sequence of the fragment is obtained from a mite and compared to other sequences of the same region deposited in the GenBank database. If this sequence shows 2 % or less difference from the one in the database, then it is considered to be a member of this particular species. Fragments from each of the 4 recognized species differ from each other by about 6 % (Anderson and Trueman, 2000). Sequences of the cox1 gene fragment have been obtained from all Varroa spp. mites that have been identified to date by molecular methods. Hence, sequences of this fragment should be incorporated into all new molecular studies on varroa mites, as it places this new work in context with what has gone before.