The following has been received from Peter Kennedy at Exeter University.

“Varroa are needed as part of a collaboration between Rothamsted Research (where I was previously based) and myself. It links to a paper that will hopefully be published soon (already accepted): González-Cabrera , J., Davies, T.G.E.,, Field, L.M., Kennedy, P.J. and Williamson, M.S. An amino acid substitution (L925V) associated with resistance to pyrethroids in Varroa destructor. PLOS ONE. The paper describes how molecular biology / chemist colleagues at Rothamsted have identified a mutated gene that is likely to be involved in the mutation that has conferred varroa resistance to the pyrethroid-based varroacide products, Apistan and Bayverol. This was based on samples collected from hives in Bedfordshire & Hampshire.

We are now keen to confirm how common this single mutation is over a broader range of counties, hence the request for varroa. For the genetic analysis, it is important that the mites have not been dead for too long to avoid deterioration of DNA. Live would be even better, that is harder to achieve; we’ll take them dead or alive. Hence the request for varroa mites or board scrapings within a few days of clean boards being added under mesh floors (or trays inserted onto solid floors). To avoid the additional delay in transit of samples coming to me and having to forward them on, I am asking people to send samples directly to my colleague, Joel Gonzalez Cabrera, at Rothamsted (see address below). To make sense of the samples, we also need some additional information (as described below) and are particularly keen to receive samples from colonies that have received either Apistan or Bayvarol within the last 5 years (but are equally keen to receive varroa samples that haven’t).”

How to collect and supply samples

Collecting Mites Using Bottom Board

• slide in your clean board (if in already, just slide out to clean first and return).
• leave in for 24 – 48 hrs.
• collect all mites as you count them (place in small container), or … just brush everything into a sealable bag.
• mites from each hive in a different container/bag.

Mites need to arrive within 7 days of boards going in; e.g. set up Sunday, collect Tuesday, & post Tuesday/Wednesday.

Sending Mites

Include the following details:

• your name.
• your address (approximate if you prefer; postal address if you’d like to receive results).
• colony ID.
• dates & details of previous treatments.

Send mites & details 1st class to:

Joel Gonzalez Cabrera,Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ.

Mites need to arrive within 7 days of boards going in; e.g. set up Sunday, collect Tuesday, & post Tuesday/Wednesday.

This is interesting research towards understanding and perhaps control the process of resistance to treatments.

The team, led by Dr Stephen Martin from the University of Sheffield working in Hawaii, has identified how Varroa results in a lethal strain of the Deformed Wing Virus becoming dominant in the bee colony.

See coverage of the report on the BBC Nature or, better, the Guardian website.

Since its arrival in Wales in 1994  the varroa mite has become the major threat to honeybees. It is also evolving resistance to the treatments originally used to manage it. You should monitor the level of the mite in your hives regularly and take action to deal with infestation.

These articles from Scientific Beekeeping may be of interest if you want more information about using icing sugar (powdered sugar) as a non-chemical method of mite control.

• Part 1
• Part 2
• Part 3