Climate change: Potential impacts on honey bee populations and diseases

Transcription

1 Climate change: Potential impacts on honey bee populations and diseases Yves Le Conte INRA, UMR 406 Abeilles et Environnement, AVIGNON, France

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3 Effects on honey bees?

4 10 honey bee species Bees in highly diverse climates Important distribution range

5 25 Apis mellifera sub-species including different ecotypes adapted to their biotopes Adaptation to very diverse biotopes Genetic variability and biodiversity

6 Impacts on different levels: - Bees : Individual and colony level - Floral environment - Diseases, pathogens and predators - Beekeeping management

7 Individual level: Ex: Foraging behavior Bees adapt their foraging behavior to meteorological conditions: Do not forage when it is raining Warm weather means more water foraging and fanning.

8 Colony level : Thermoregulation Development cycle Amount of brood Louveaux et al, Ann. Abeille, 1966 Time (months)

9 Climate influences Flower development Nectar and pollen production Honey bee foraging and colony development

10 Nectar foraging: More dryness less nectar, no aphids Too much rain washed flowers, no honey

11 Pollen foraging: More dryness less pollen Too much rain no foraging Fall pollen foraging:

12 Extreme example: Apis sahariensis?? Less land for the bees Honey bee conservation

13 But, what about northern countries? More land for the bees??

14 Honey bee development cycle Photo: Blaize Example of heather Louveaux et al, Ann. Abeille, 1966 What about those ecotypes?

15 Host parasite equilibrium will change Ex: extension of brood period means more varroa mites Nosema ceranae Chalk brood

16 Transfer of diseases facilitated Ex: brood period extended means a chance for Tropilaelaps to invade Apis mellifera out of Asia.

17 Invasive species Aethinea tumida

18 Impacts on different level: - Behavior and physiology of the bees - Floral environment - Diseases, pathogens and predators - Beekeeping management Needs to adapt: Change transhumance habits Look at changes in colony development Ligustica example Avignon example

19 Consequences for the geographic distribution: Natural movements Movements instigated by beekeepers Potential for adaptation Trade in honey bee Slow climate changes ecotypes adapt to new biotopes Feral colonies: example of Varroa resistant bees Photo: Blaize

20 Consequences for the geographic distribution: Natural movements Movements instigated by beekeepers Potential for adaptation Trade in honey bee Rapid climate changes Adaptation possible?? Feral colonies endangered Saving endangered subspecies (sahariensis) Photo: Blaize

21 Consequences for the geographic distribution: Natural movements Movements instigated by beekeepers Potential for adaptation Trade in honey bee Beekeepers Change beekeeping practices Move to better environments Importing queens of other races to test their potential to adapt to new climate

22 Consequences for the geographic distribution: Natural movements Movements instigated by beekeepers Potential for adaptation Trade in honey bee Important genetic variability Adaptive capacity : almost everywhere in the world highly diverse climates imported by colonists in Americas and Asia great biodiversity possibility to use this genetic variability to adapt to climate change

23 Consequences for the geographic distribution: Natural movements Movements instigated by beekeepers Potential for adaptation Trade in honey bee Needs to import bees? test their potential to adapt to new climate Example of France : Long tradition for importation royal jelly producers triple hybrids versus mellifera? High genetic variability Photo: Blaize Other countries selecting bees less variability Countries importing bees loose their own bees conservation

24 Consequences for the geographic distribution: Natural movements Movements instigated by beekeepers Potential for adaptation Trade in honey bee Honey bee conservation: conservation area (expensive) cryoconservation

25 Conclusion When actual colony losses demonstrates the fragility of honey bee Climate change will : Act directly on bee biology (individual and colony level) shift the balance between the bees, plant environment and diseases A hope:honey bee geneticdiversity and capacity to colonize diverse environments Butclimate stress can add to the various stress endangering our bees Human modify bee environment, so we have the responsibility to take conservation measures to prevent losses of this rich biodiversity. We must help the bees to adapt. For that we must support the beekeepers

26 Conclusion Few data on this topic: very prospective Needs for collaboration with bee biologists and climatologists