Hi All As regards the query as to when Varroa crossed the species barrier I think it has something to do with this: A.cerana has a weak guarding system. Hence A.mellifera tends to rob A.cerana colonies early in the morning. The bees would crawl into the hives over the bottom boards. A.cerana has very bad hive hygene, chewing combs and letting the toolings drop to the floor where they accumulate. Hence one would theorize that much of varroa infection naturally with cerana would probably be from mites crawling onto bees after dropping down into this muck. A.cerana has actually been quite badly damaged by the fact that natural hives are raided by A.mel hives. Keep well Garth --- Garth Cambray Camdini Apiaries 15 Park Road Apis melifera capensis Grahamstown 800mm annual precipitation 6139 Eastern Cape South Africa Phone 27-0461-311663 On holiday for a few months Rhodes University Which means: working with bees 15 hours a day! Interests: Fliis and bees Disclaimer: The views and opinions expressed in this post in no way reflect those of Rhodes University.