Good afternoon everybody This was one of the main topics on Apimondia Congress at Kiev. Jeff Pettis talked about his investigations on 23 drone laying queens. 64% was fully inseminated and 36 % poorly. He found and average of 62% of dead sperm compared to normal queens around 15%. Here it is the abstract published in the Apimondia Congress' book. The Role Of Pesticides In Queen Health & Sperm Viability USDA Agricultural Research Service Bldg 306 BARC-E 10300 Baltimore Ave, Beltsville, 20705, USA Dr. Jeff Pettis 301 504-7299, jeff.pettis ars.usda.gov In honeybees, queen health is vital to the survival of the colony. In many parts of the world queens are failing or being superseded after as little as six month instead of the 1-2 year life span that is often reported. To explore possible causes of queen failure we disssected queens from failing colonies, including drone laying queens and measured mating success and sperm viability. Additionally, we treated healthy queens with various low doses of pesticides, based on the amounts found in adult bees and wax, and then measured sperm viability. We found that many drone laying queens still had sperm present but at a mortality rate above normal. Similarly, we found that queens from failing colonies had high sperm mortality compared to queens in healthy colonies. Lastly, when we artificially treated queens with sub-letal dosages of pesticides we could kill up to 50% of sperm in only 7 days. Experiments are underway to look at the relationship between failing colonies, poor brood patterns and sperm viability. We have demostrated that queens from failing colonies can have high leves of dead sperm. Experiments are underway to look at booth pesticide exposures to drones and or mated queens to determine the source of the dying sperm relative to pesticide exposure. We hope to be able to report on the role that several pesticides may play in sperm viability and queen survivorship. We have data to support the conclusion that queens in failing colonies have high levels of dead sperm; the possible reasons, including pesticide exposure, for the dying sperm will be discussed. best regards fernando Córdoba - Arg. *********************************************** 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