>I'm wonder what finally wore them down and what was, if anything, connected to the artificial diet. Hi Grant, Nurse bees will dig into their body reserves to supply critical nutrients to the brood. This is especially true for sterols, esp 24-methylene cholesterol. Research has shown that their reserves are good for a couples of brood cycles (can't cite off the top of my head). My guess, and it's only a guess, is that the colonies ran out of a critical nutrient, that was supplied by the beebread that cured the problem.bread. Randy Oliver ******************************************************* * Search the BEE-L archives at: * * http://listserv.albany.edu:8080/cgi-bin/wa?S1=bee-l * *******************************************************