The postings by Randy and Stan have redirected my sunday morning reading away from the usual collection of political joustings in the newspapers, to more scholarly articles on the defence mechanisms utilised by insects against parasites and pathogens! (Thanks guys, I find that a far less stressful way to pass my valuable leisure time). Although I am not an entomologist I do have enough scientific background to understand much of what I have read. It is clearly apparant that knowledge has advanced tremendously in the relatively short time since I last focussed on this subject. But what has not changed is the importance of the social or behavioural immunity mechanisms deployed for protection by colony insects such as termites and honeybees. Whilst as Randy has pointed out these differ from, and should not be confused with, the innate or humoural immunity systems, they are well enough understood for us to be able to take advantage of them to improve (eg Hygienic Behaviour selection in honeybees) or reduce (eg use of Imidacloprid to disrupt Grooming Behaviour in termites) fitness for survival for these insects. Indeed, at the humble practising beekeeper level, utilising the very simple pin killed brood test has enabled us to select for enhanced Hygienic Behaviour in our bees. Breeders selection based on this test has made a huge impact on the incidence of AFB and Chalkbrood infected colonies in this part of the world, as I am sure it has in others. And it costs nothing. What I have been waiting for is a similarly useful and simple method to select for enhanced Grooming Behaviours in honeybees to improve their ability to deal with varroa. I haven't seen any evidence of the development of such a test....maybe I missed it? I have always assumed, perhaps incorrectly, that the breeding efforts focussed on SMR bees was a move in this direction, since they did appear to have quite enhanced grooming characteristics. But I am sure that there is a lot more than meets my eyes in that story. Whilst I am fascinated and encouraged by the work on RNAi and efforts to bring products using this technology to market, I am cognisant of the limitations that a costly treatment will have in dealing with the varroa problem, compared to a more widely, husbandry-based system. I am just grateful that I live in Western Australia where we still don't have the varroa problem. Peter Detchon *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html Guidelines for posting to BEE-L can be found at: http://honeybeeworld.com/bee-l/guidelines.htm