Social-medication in bees: the line between individual and social regulation

Authors: SPIVAK, MARLA - University Of Minnesota; GOBLIRSCH, MICHAEL - University Of Minnesota; Simone-Finstrom, Michael

Submitted to: Current Opinion in Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2019
Publication Date: 4/27/2019
Citation: Spivak, M., Goblirsch, M., Simone-Finstrom, M. 2019. Social-medication in bees: the line between individual and social regulation. Current Opinion in Insect Science. 33:49-55. https://doi.org/10.1016/j.cois.2019.02.009.
DOI: https://doi.org/10.1016/j.cois.2019.02.009

Interpretive Summary: Social insects have evolved a series of behaviors to defend themselves and their colonies against parasites. Behavioral defenses that protect the colony against parasites and pathogens are described as social immunity. One aspect of social immunity that is not well understood is the concept of therapeutic medication. Honey bees, bumblebees and other species collect plant-based compounds that have medicinal value. In some cases, bees have been shown to self-medicate with these compounds. Self-medication occurs when an individual is sick and they preferentially forage on materials that reduce their own infection. However, here we describe social medication, whereby the colony is the sick individual and bees bring in resources to reduce infection at the colony level. The goal of this review is to provide examples of consumption and use of plant compounds by social bees (e.g., bumblebees, stingless bees and honey bees) that have a demonstrated role in parasite defense and health of the colony, and when possible, delineate whether they are examples of self-medication or what we are calling social-medication. Understanding bee defenses against parasites and pathogens is key to improving their resiliency.

Technical Abstract: We use the term social-medication to describe the deliberate consumption or use of plant compounds by social insects that are detrimental to a pathogen or parasite at the colony level, result in increased inclusive fitness to the colony, and have potential costs either at the individual- or colony-level in the absence of parasite infection. These criteria for social-medication differ from those for self-medication in that inclusive fitness benefits and costs are distinguished from individual costs and benefits. We consider social medication to be a form of social immunity if the plant compounds are shared among nestmates and help fight infection to increase colony health and survival. We provide examples among social bees (bumblebees, stingless bees and honey bees) in which the consumption or use of plant compounds have a demonstrated role in parasite defense and health of the colony. We indicate when more work is needed to distinguish between prophylactic and therapeutic effects of these compounds, and whether the effects are observed at the individual or colony-level.