Resin collection and social immunity in honey bees

Authors: SIMONE, MICHAEL - UNIVERSITY OF MINNESOTA; Evans, Jay; SPIVAK, MARLA - UNIVERSITY OF MINNESOTA

Submitted to: Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2009
Publication Date: 9/3/2009
Citation: Simone, M., Evans, J.D., Spivak, M. 2009. Resin collection and social immunity in honey bees. Evolution. 63:3016-3022.

Interpretive Summary: Honey bees can combat disease at the individual and colony level. Propolis (plant resins collected by bees and used throughout the nest) collection is carried out by all honey bees, though the effects of propolis on bee health are poorly understood. Since propolis has antimicrobial properties, we predicted that higher levels of propolis could relieve pressure on other honey bee disease responses. In fact, colonies whose hive boxes were coated with propels showed lower bacterial levels and lower immune expenses. This information suggests that bee propolis levels could be manipulated as one way to improve productivity and disease resistance in the field. A management tool such as that would prove helpful for beekeepers and bee breeders.

Technical Abstract: We determined if the use of resins, complex plant secretions with diverse antimicrobial properties, acts as a colony-level immune defense by honey bees. Colonies were enriched with extracts of Brazilian or Minnesotan propolis (a bee mixture of resins and wax) or were left as controls. We measured gene transcript levels of four antimicrobial peptides and one gene involved in cellular immunity to determine if the presence of propolis can compensate for individual immune responses. Honey bees in propolis-rich colonies showed lower immune transcript levels and lower overall bacterial loads, providing evidence that the nest environment affects these traits.