title: Prospective large-scale field study generates predictive model identifying major contributors to colony losses.
abstract: Over the last decade, unusually high losses of colonies have been reported by beekeepers across the USA. Multiple factors such as Varroa destructor, bee viruses, Nosema ceranae, weather, beekeeping practices, nutrition, and pesticides have been shown to contribute to colony losses. Here we describe a large-scale controlled trial, in which different bee pathogens, bee population, and weather conditions across winter were monitored at three locations across the USA. In order to minimize influence of various known contributing factors and their interaction, the hives in the study were not treated with antibiotics or miticides. Additionally, the hives were kept at one location and were not exposed to potential stress factors associated with migration. Our results show that a linear association between load of viruses (DWV or IAPV) in Varroa and bees is present at high Varroa infestation levels (>3 mites per 100 bees). The collection of comprehensive data allowed us to draw a predictive model of colony losses and to show that Varroa destructor, along with bee viruses, mainly DWV replication, contributes to approximately 70% of colony losses. This correlation further supports the claim that insufficient control of the virus-vectoring Varroa mite would result in increased hive loss. The predictive model also indicates that a single factor may not be sufficient to trigger colony losses, whereas a combination of stressors appears to impact hive health.
authors: Monsanto Company, Chesterfield, Missouri, United States of America.
authors: Merav Gleit
authors: MG
authors: Kielmanowicz
authors: Monsanto Company, Chesterfield, Missouri, United States of America.
authors: Alex
authors: A
authors: Inberg
authors: Monsanto Company, Chesterfield, Missouri, United States of America.
authors: Inbar Maayan
authors: IM
authors: Lerner
authors: Monsanto Company, Chesterfield, Missouri, United States of America.
authors: Yael
authors: Y
authors: Golani
authors: Monsanto Company, Chesterfield, Missouri, United States of America.
authors: Nicholas
authors: N
authors: Brown
authors: Monsanto Company, Chesterfield, Missouri, United States of America.
authors: Catherine Louise
authors: CL
authors: Turner
authors: Monsanto Company, Chesterfield, Missouri, United States of America.
authors: Gerald J R
authors: GJ
authors: Hayes
authors: Monsanto Company, Chesterfield, Missouri, United States of America.
authors: Joan M
authors: JM
authors: Ballam
mesh_terms: D000818:Animals; D001516:Bees / Q000469:parasitology*; D056631:Colony Collapse / Q000453:epidemiology* / Q000469:parasitology*; D015995:Prevalence; D011446:Prospective Studies; D057077:Varroidae; D014777:Virus Diseases / Q000453:epidemiology