Journal Article

The carry-over effects of pollen shortage decrease the survival of honeybee colonies in farmlands

Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Zone Atelier Plaine et Val de Sèvre (LTSER-ZAPVS) ; LTSER Réseau des Zones Ateliers (RZA) ; Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Henry, Mickaël, UMT Protection des abeilles dans l’environnement (UMT PrADE) ; Association pour le Developpement de l'Apiculture Provencale (ADAPI)-Institut de l'abeille (ITSAP)-Centre National de la Recherche Scientifique (CNRS)-Terres Inovia-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Entomologie (

2017

Overview

1. Many studies have reported honeybee colony losses in human-dominated landscapes.While bee floral food resources have been drastically reduced over past decades in humandominatedlandscapes, no field study has yet been undertaken to determine whether there is acarry-over effect between seasonal disruption in floral resource availability and high colonylosses.2. We investigated if a decline in the harvest of pollen by honeybees in spring affected managedhoneybee colony dynamics (brood size, adult population and honey reserves) and health(Varroa mite loads and colony survival) throughout the beekeeping season.3. A decline in pollen harvest was associated with a direct reduction in brood production,leading to a negative effect on the adult population size later in the season, and lower honeyreserves before the onset of winter. Furthermore, the decline in pollen harvest negativelyimpacted the health of the colony, resulting in higher Varroa mite loads and higher seasonaland winter colony losses.4. Early-warning signs of these carry-over effects were identified, showing that preferentialinvestment in honey reserves instead of brood production early in the season increased thedecline in pollen harvest and its associated carry-over effects.5. Synthesis and applications. The results suggest that the decline in pollen harvest may havebeen overlooked as a cause of pollen shortage and associated bee colony losses. Strategies toavoid such losses in intensive farmland systems include (i) limiting or avoiding honey harvestsin spring, (ii) monitoring colonies for early-warning signals of colony failure and (iii) increasingthe amount of floral resources available through wise land-use management.

• Publisher: Wiley,CCSD,John Wiley & Sons Ltd,Blackwell Publishing Ltd
• Subject: adults / Agricultural land / Agricultural landscapes / Apiculture / Apis mellifera / Beekeeping / Bees / carry‐over effects / Colonies / Constraining / Direct reduction / Dynamical systems / Environmental Sciences / Financing / floral resource scarcity / Food resources / Harvesting / Honey / honey bee colonies / honey bees / honeybee colony losses / Intensive farming / Land management / Land use / Land use management / Landscape / landscapes / life‐history strategy / Loads (forces) / Mites / monitoring / Pollen / Population number / population size / Reserves / Resource availability / Resource management / Seasons / Signal monitoring / Spring / Spring (season) / Survival / trade‐offs / Varroa / Varroa mite / Warning / Warning systems / Winter
• ISBN: 0004055345000