However, what is the actual mechanism that causes a dead out in a colony in > Jan. where the count is > over 6% ? > > > My question is, does the beekeeper community recognize any standard of a > post mortem exam of a dead out? > > When looking at deadouts in the spring. The ones I generally attribute to varroa have nearly all of their winter stores and a very small cluster of dead bees. Sometimes a couple of small patches of dead brood. Empty comb in the brood nest has significant mite droppings or "frass". There is often a lot of dead varroa in the junk on the bottom board and along the edge of entrance reducer. Basically the colony hits a breaking point from mite load and viruses and steadily dwindles down to small cluster with the bulk of the sick bees flying off to die. In our area, brood area has generally ceased by or before Nov 1 and won't start up again until late February/early March. Adam Barrie, ON *********************************************** 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