I am involved in a project to select a honey bee stock with other desireable characteristics, from within a population which is resistant to tracheal mites. Do any of you know of evidence that may support (or not) the notion that the first crossing of un-related, low-aggression lines often results in high aggression, which then dissappears (regardless of selection) in subsequent generations. Kerry Clark, Apiculture Specialist B.C. Ministry of Agriculture 1201 103 Ave Dawson Creek B.C. V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299 INTERNET [log in to unmask]