Hi All Bob wrote about Diana Cox-Foster, reminding us that comb can be virus-contaminated. Steve asked: > 1. How many years can you safely use brood comb? It seems > like you could have virus infected comb after one season and Chris asked: > How do they persist on comb? For how long? Here (http://www.bbka.org.uk/articles/bee_diseases.php) it is stated that Sac Brood Virus becomes non-infective within a few weeks. Longer than many viruses away from their hosts, but not long enough to for re-infection from equipment vacated in the winter and re-occupied in the subsequent summer. Of the other picorna viruses more strongly associated with Parastic Mite Syndrome, I know nothing. Does anyone? Bob mentioned that Diana Cox-Foster's research, suggesting that comb renewal could be important to reduce virus load. Reading her papers (this one in particular): http://vir.sgmjournals.org/cgi/content/full/86/8/2281 .. it would seem that Varroa and its saliva does carry some picorna-like viruses and could be a vector, but also the queen lays virus-contaminated eggs and that worker to larva transmission takes place. Simply renewing comb is unlikely to break the cycle of infection with this and related viruses, and so I doubt that comb renewal could be justified on this issue alone. One of our regulars wrote this back in 1999: "Destroying older combs that are still in good shape is another of those things small-time beekeepers do to make sure that they stay small-time." Yet comb renewal has become a popular call - does anyone have concrete evidence of a benefit from comb renewal, beyond the possibility of relief from Foulbrood, Nosema and perhaps Chalkbrood? all the best Gavin ****************************************************** * Full guidelines for BEE-L posting are at: * * http://www.honeybeeworld.com/bee-l/guidelines.htm * ******************************************************