|Schneider, Stanley - UNIV. NORTH CAROLINA|
Submitted to: Insectes Sociaux
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 17, 2004
Publication Date: November 20, 2004
Citation: Schneider, S.S., Deeby, T., Gilley, D.C. and DeGrandi-Hoffman, G. Seasonal nest usurpation of European colonies by African swarms in Arizona, USA. Insect. Soc. 51:359-364. 2004. Interpretive Summary: Nest usurpation (also known as colony takeover) consists of a small swarm of African honey bees invading a European honey bee colony. The African queen in the swarm replaces the European queen in the invaded colony. Colony takeover has been suggested to play a role in the success of African bees in the New World. While nest usurpation has been previously documented in South America, it has not been reported to occur in the U.S. We monitored usurpation activity over a two-year period in an apiary with 76 five-frame nucleus colonies in Tucson, AZ. Each colony was headed by a "Golden Italian" European queen. We examined the colonies every 10-14 days to determine if the colony was thriving, weak or queenless. Weak colonies were requeened. We observed an average annual usurpation rate of 21.1 plus or minus 9.3%. The greatest usurpation activity occurred from October-December and coincided with the period of seasonal absconding by African bees in the Tucson region. Thriving and weak colonies experienced similar, low monthly usurpation rates. However, queenless colonies and those that had a caged queen or had been recently requeened were 2-8 times more likely to be invaded especially in the fall-winter. These results suggest that cues associated with compromised queen condition or diminished brood rearing could be used by usurpation is an important, but annually variable factor contributing to the spread of African bees in the southwestern U.S.