title: The effects of single and mixed infections of Apicystis bombi and deformed wing virus in Bombus terrestris.
abstract: Many pollinators are currently suffering from declines, diminishing their gene pool and increasing their vulnerability to parasites. Recently, an increasing diversity of parasites has been recorded in bumblebees, yet for many, knowledge of their virulence and hence the risk their presence poses, is lacking. The deformed wing virus (DWV), known to be ubiquitous in honey bees, has now been detected in bumblebees. In addition, the neogregarine Apicystis bombi has been discovered to be more prevalent than previously thought. Here, we assess for the first time the lethal and sublethal effects of these parasites during single and mixed infections of worker bumblebees (Bombus terrestris). Fifteen days after experimental exposure, 22% of bees exposed to A. bombi, 50% of bees exposed to DWV and 86% of bees exposed to both parasites had died. Bumblebees that had ingested A. bombi had increased sucrose sensitivity (SS) and a lower lipid:body size ratio than control bees. While dual infected bumblebees showed no increase in SS. Overall, we find that A. bombi exhibits both lethal and sublethal effects. DWV causes lethal effect and may reduce the sub lethal effects imposed by A. bombi. The results show that both parasites have significant, negative effects on bumblebee health, making them potentially of conservation concern.
authors.affiliation: Institute of Integrative and Comparative Biology,University of Leeds,Leeds LS2 9JT,UK.
authors.forename: Peter
authors.identifier: http://orcid.org/0000-0002-0248-2571
authors.initials: P
authors.lastname: Graystock
authors.affiliation: Department of Crop Protection,Faculty of Bioscience Engineering,Ghent University,Ghent,Belgium.
authors.forename: Ivan
authors.initials: I
authors.lastname: Meeus
authors.affiliation: Department of Crop Protection,Faculty of Bioscience Engineering,Ghent University,Ghent,Belgium.
authors.forename: Guy
authors.initials: G
authors.lastname: Smagghe
authors.affiliation: School of Life Sciences,University of Sussex,Brighton BN1 9QG,UK.
authors.forename: Dave
authors.initials: D
authors.lastname: Goulson
authors.affiliation: School of Life Sciences,University of Sussex,Brighton BN1 9QG,UK.
authors.forename: William O H
authors.initials: WO
authors.lastname: Hughes
mesh_terms: D000818:Animals; D016782:Apicomplexa / Q000502:physiology*; D001516:Bees / Q000737:chemistry / Q000187:drug effects / Q000469:parasitology* / Q000821:virology*; D049628:Body Size / Q000502:physiology; D008055:Lipids / Q000032:analysis; D010849:Picornaviridae / Q000502:physiology*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D013395:Sucrose / Q000494:pharmacology; D016019:Survival Analysis
chemical_list: D008055:Lipids; D012337:RNA, Ribosomal, 18S; D013395:Sucrose
keywords: DWV; emerging disease; neogregarine; pathogen; pollinator