I am puzzled. The following is an extract from "Varroasis disease of honey bees - diagnosis and control", a MAFF (British agriculture ministry) publication:- "A mated female mite enters the brood cell a few hours before it is capped. ... She begins to lay single eggs at intervals of about 30 hours. ... The first egg develops into a male, the remainder become females with which the male eventually mates, inside the capped cell. ... Male mites never feed or leave the cell and presumably die after the bee emerges." I get the same story from other publications. "Living with Varroa jacobsoni", by the Devon Apicultural Research Group, agrees in most respects although it says "either the first or second egg will develop into a male; all others develop into females". It confirms that the mites mate in the sealed cell and the male (and any unmated females) die when the bee emerges. I have read the same thing elsewhere and heard it in lectures I have attended. It would appear that the female mite _always_ mates with her brother. Is this true? If so, does it only apply when Apis mellifera is parasitized or is it the same with A. cerana, its traditional host? If it is true, then there is no efficient mechanism for spreading advantageous mutations, the 'reason' for sexual reproduction. So why is there concern about the acquisition of drug immunity? None of the publications I have read have quoted sources for the assertion. I suppose it is possible that they have all obtained their information from the same, incorrect, source. I apologise if this has been discussed here before - I have only been subscribed to BEE-L for a short time - but I would still be interested in some answers. -- Malcolm Roe Phone : +44 442 230000 ext 4104 Crosfield Electronics Ltd Fax : +44 442 232301 Hemel Hempstead, Herts. HP2 7RH, UK E-mail : [log in to unmask] ------------------------------------------------------------------------