As promised a quick run down about Varroa.
Before I begin I must add that a colleague in Eire was asked to give a talk on Varroa. He researched this quite extensively and I will be using some of his work, his name is Ruary Rudd.
Varroa destructor was, until recently, thought to be a close related mite species to Varroa jacobsoni. Both species parasitize the Asian honey bee, Apis cerana. However, the species originally described as V. jacobsoni by Qudemans in 1904 is not the same species that also attacks Apis mellifera. The jump to mellifera probably first took place in the Philippines in the early 1960?s where imported Apis mellifera came into close contact with the infected Apis cerana. Up until 2000 scientists had not identified Varroa destructor as a separate species. This late identification in 2000 by Anderson and Trueman corrected some previous confusion and mislabelling in the scientific literature. As of 1005 the only Varroa mites that can reproduce in colonies of Apis mellifera (Western honey bee) are the Korea and Japan/Thailand genotypes of Varroa destructor.
There are several different species of Varroa, Varroa jacobsoni was found on a bee Apis cranea in 1902 by a man called Jacobson it was described by Oudemans and this mite did not damage Apis mellifera. Later on Apis mellifera came into contact with another varroa (the Korean haplotype) and researchers did not examine the beast carefully and misidentified it as Varroa jacobsoni. This mite caused devastation (as we all know) on Apis mellifera stocks.
In 1998 a scientist called Anderson checked out DNA of various mites which were called Varroa jacobsoni and found that there were six different species.
From Wikipedia;
Varroa jacobsoni mites are a relatively benign parasite of Apis cerana (Asian honey bees).
Until very recently it was thought that they were the cause of the varroatosis, a parasitic disease that plagues Western honey bees, Apis mellifera, since the early 1960s. Only in 2000 a separate species of Varroa, Varroa destructor, was positively identified as the only Varroa mites that can reproduce in colonies of Apis mellifera.
To help you to understand it better I have added what certain scientific words mean.
Haplotype; A haplotype is a set of genes in a piece of DNA that all have the same variant. This could be a little bit of a chromosome, or in organisms that don?t mix up bits of the chromosomes by crossing ?over (such as inbred Varroa mites), the whole genome.
In the case of Varroa mites, when you say it has haplotype variant A it just means the whole mite is type A.
Hope this has helped in understanding a little bit more about Varroa.
Regards;