Ganz interessantes paper, fuer jeden frei lesbar bei PLOS.one (auf englisch; Google uebersetzt aber willig) - Kurzzusammenfassung: Bienen sammeln verstaerkt Propolis nach Infektion mit Kalkbrut.
Increased Resin Collection after Parasite Challenge: A
Case of Self-Medication in Honey Bees?
Michael D . Simone-Finstrom
Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America
Department of Entomology, University of Minnesota, St. Paul, Minnesota, United States of America
The constant pressure posed by parasites has caused species throughout the animal kingdom to evolve suites of
mechanisms to resist infection. Individual barriers and physiological defenses are considered the main barriers against
parasites in invertebrate species. However, behavioral traits and other non-immunological defenses can also effectively
reduce parasite transmission and infection intensity. In social insects, behaviors that reduce colony-level parasite loads are
termed "social immunity." One example of a behavioral defense is resin collection. Honey bees forage for plant-produced
resins and incorporate them into their nest architecture. This use of resins can reduce chronic elevation of an individual
bee's immune response. Since high activation of individual immunity can impose colony-level fitness costs, collection of
resins may benefit both the individual and colony fitness. However the use of resins as a more direct defense against
pathogens is unclear. Here we present evidence that honey bee colonies may self-medicate with plant resins in response to
a fungal infection. Self-medication is generally defined as an individual responding to infection by ingesting or harvesting
non-nutritive compounds or plant materials. Our results show that colonies increase resin foraging rates after a challenge
with a fungal parasite (Ascophaera apis: chalkbrood or CB). Additionally, colonies experimentally enriched with resin had
decreased infection intensities of this fungal parasite. If considered self-medication, this is a particularly unique example
because it operates at the colony level. Most instances of self-medication involve pharmacophagy, whereby individuals
change their diet in response to direct infection with a parasite. In this case with honey bees, resins are not ingested but
used within the hive by adult bees exposed to fungal spores. Thus the colony, as the unit of selection, may be responding to
infection through self-medication by increasing the number of individuals that forage for resin.