title: Evaluation of the distribution and impacts of parasites, pathogens, and pesticides on honey bee (Apis mellifera) populations in East Africa.
abstract: In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations.
authors.affiliation: The International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya; Department of Biological Sciences, South Eastern Kenya University (SEKU), Kitui, Kenya.
authors.forename: Elliud
authors.initials: E
authors.lastname: Muli
authors.affiliation: Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: Harland
authors.initials: H
authors.lastname: Patch
authors.affiliation: Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: Maryann
authors.initials: M
authors.lastname: Frazier
authors.affiliation: Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: James
authors.initials: J
authors.lastname: Frazier
authors.affiliation: The International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
authors.forename: Baldwyn
authors.initials: B
authors.lastname: Torto
authors.affiliation: Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: Tracey
authors.initials: T
authors.lastname: Baumgarten
authors.affiliation: The International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
authors.forename: Joseph
authors.initials: J
authors.lastname: Kilonzo
authors.affiliation: The International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
authors.forename: James Ng'ang'a
authors.initials: JN
authors.lastname: Kimani
authors.affiliation: The International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
authors.forename: Fiona
authors.initials: F
authors.lastname: Mumoki
authors.affiliation: The International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
authors.forename: Daniel
authors.initials: D
authors.lastname: Masiga
authors.affiliation: Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: James
authors.initials: J
authors.lastname: Tumlinson
authors.affiliation: Department of Entomology, Center for Pollinator Research, Pennsylvania State University, University Park, Pennsylvania, United States of America.
authors.forename: Christina
authors.initials: C
authors.lastname: Grozinger
mesh_terms: D000351:Africa, Eastern; D000818:Animals; D001516:Bees / Q000187:drug effects / Q000469:parasitology / Q000502:physiology*; D003247:Conservation of Natural Resources; D004781:Environmental Exposure; D054884:Host-Pathogen Interactions; D010575:Pesticides / Q000633:toxicity*; D054817:Pollination; D011157:Population Dynamics; D057077:Varroidae / Q000502:physiology
chemical_list: D010575:Pesticides
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