title: Hygienic food to reduce pathogen risk to bumblebees.
abstract: Bumblebees are ecologically and economically important pollinators, and the value of bumblebees for crop pollination has led to the commercial production and exportation/importation of colonies on a global scale. Commercially produced bumblebee colonies can carry with them infectious parasites, which can both reduce the health of the colonies and spillover to wild bees, with potentially serious consequences. The presence of parasites in commercially produced bumblebee colonies is in part because colonies are reared on pollen collected from honey bees, which often contains a diversity of microbial parasites. In response to this threat, part of the industry has started to irradiate pollen used for bumblebee rearing. However, to date there is limited data published on the efficacy of this treatment. Here we examine the effect of gamma irradiation and an experimental ozone treatment on the presence and viability of parasites in honey bee pollen. While untreated pollen contained numerous viable parasites, we find that gamma irradiation reduced the viability of parasites in pollen, but did not eliminate parasites entirely. Ozone treatment appeared to be less effective than gamma irradiation, while an artificial pollen substitute was, as expected, entirely free of parasites. The results suggest that the irradiation of pollen before using it to rear bumblebee colonies is a sensible method which will help reduce the incidence of parasite infections in commercially produced bumblebee colonies, but that further optimisation, or the use of a nutritionally equivalent artificial pollen substitute, may be needed to fully eliminate this route of disease entry into factories.
authors.affiliation: School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK; Department of Entomology, University of California, Riverside, CA 92507, USA.
authors.forename: P
authors.initials: P
authors.lastname: Graystock
authors.affiliation: School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
authors.forename: J C
authors.initials: JC
authors.lastname: Jones
authors.affiliation: School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
authors.forename: T
authors.initials: T
authors.lastname: Pamminger
authors.affiliation: School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
authors.forename: J F
authors.initials: JF
authors.lastname: Parkinson
authors.affiliation: School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
authors.forename: V
authors.initials: V
authors.lastname: Norman
authors.affiliation: Natural England, Mail Hub Block B, Whittington Road, Worcester WR5 2LQ, UK.
authors.forename: E J
authors.initials: EJ
authors.lastname: Blane
authors.affiliation: Bumblebee Conservation Trust, Cottrell Building, University of Stirling, Stirling FK9 4LA, UK.
authors.forename: L
authors.initials: L
authors.lastname: Rothstein
authors.affiliation: Biobest NV, Ilse Velden 18, B-2260 Westerlo, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Wäckers
authors.affiliation: School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK.
authors.forename: D
authors.initials: D
authors.lastname: Goulson
authors.affiliation: School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK. Electronic address: william.hughes@sussex.ac.uk.
authors.forename: W O H
authors.initials: WO
authors.lastname: Hughes
mesh_terms: D000818:Animals; D001516:Bees / Q000469:parasitology*; D005720:Gamma Rays; D010271:Parasites / Q000528:radiation effects; D011058:Pollen / Q000469:parasitology* / Q000528:radiation effects*; D013242:Sterilization / Q000379:methods*
keywords: Apicystis; Bombus; Commercially produced bumblebees; Disease; Pollen; Pollination services