title: An Inert Pesticide Adjuvant Synergizes Viral Pathogenicity and Mortality in Honey Bee Larvae.
abstract: Honey bees are highly valued for their pollination services in agricultural settings, and recent declines in managed populations have caused concern. Colony losses following a major pollination event in the United States, almond pollination, have been characterized by brood mortality with specific symptoms, followed by eventual colony loss weeks later. In this study, we demonstrate that these symptoms can be produced by chronically exposing brood to both an organosilicone surfactant adjuvant (OSS) commonly used on many agricultural crops including wine grapes, tree nuts and tree fruits and exogenous viral pathogens by simulating a horizontal transmission event. Observed synergistic mortality occurred during the larval-pupal molt. Using q-PCR techniques to measure gene expression and viral levels in larvae taken prior to observed mortality at metamorphosis, we found that exposure to OSS and exogenous virus resulted in significantly heightened Black Queen Cell Virus (BQCV) titers and lower expression of a Toll 7-like-receptor associated with autophagic viral defense (Am18w). These results demonstrate that organosilicone spray adjuvants that are considered biologically inert potentiate viral pathogenicity in honey bee larvae, and guidelines for OSS use may be warranted.
authors.affiliation: Department of Entomology, Center for Pollinator Research, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Julia D
authors.initials: JD
authors.lastname: Fine
authors.affiliation: Department of Entomology, Center for Pollinator Research, The Pennsylvania State University, University Park, PA 16802, USA.|USDA-ARS-PWA Pollinating Insect Research Unit, Logan, UT 84322, USA.
authors.forename: Diana L
authors.initials: DL
authors.lastname: Cox-Foster
authors.affiliation: Department of Entomology, Center for Pollinator Research, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Mullin
mesh_terms: D000818:Animals; D001516:Bees / Q000187:drug effects / Q000821:virology*; D056629:Dicistroviridae / Q000187:drug effects / Q000472:pathogenicity*; D007814:Larva / Q000187:drug effects / Q000821:virology; D017646:Organosilicon Compounds / Q000737:chemistry; D010575:Pesticides / Q000633:toxicity*; D013501:Surface-Active Agents / Q000737:chemistry; D016019:Survival Analysis
chemical_list: D017646:Organosilicon Compounds; D010575:Pesticides; D013501:Surface-Active Agents