Agricultural production: plan for a sustainable future with honey bees? · Agricultural production: plan for a sustainable future with honey bees? Robin Crewe and Robin Moritz Social

Agricultural production: plan for a sustainable future with

honey bees?

Robin Crewe and Robin MoritzSocial Insects Research Group

Department of Zoology and Entomology

Actually a world without honey bees!

Actually we do know what the world looked like without bees

Origins of Bees

The early Cretaceous era (145-113 mya) when flowering plants and their associated bees emerged for the first time.

Collaboration between evolving flowering plants and early bee species started in the relatively dry regions of Western Gondwana some 120 million years ago

Oldest fossil bee worker –stingless bee

Relationship between Fossil bees and contemporary species

~40 species ->761 species

Vegan ancestral wasp

Oligocene climates- 34 -23 mya

warm temperate

warm temperate

warm temperate

cool temperate

arid

arid

arid

arid

arid

warm temperate

warm temperate

tropical

tropical

tropical

cold

Types of honey bees

Open nest species

Cavity nesting species

Honey bee extinction

Stars indicate fossil worker bees in amber

Recent radiation of populations

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Colony densities per km2

Jaffe et al. Cons. Biol 2010

Distribution of Apis cerana

Relationship between Fossil bees and contemporary species

~40 species ->761 species

Vegan ancestral wasp

Decline in managed bee colonies?-FAO data

Whole Europe

World

Southern Europe

Moritz and Erler 2016

Honey production

Moritz and Erler 2016

Honey production/colony

Moritz and Erler 2016

What is the FAO data NOT telling us?

• Pollination services do not get measured by national governments-measuring products and not services

• The number of colonies used in providing pollination services is not recorded.

• There is no current method for determining what the pollination service deficit will be in the future.

• Pollination services are a unique national requirement that must be provided locally. Cannot be outsourced!

Provision of Pollination Services

• Essential for productive industrial agriculture

• Dependent on reliable supply of managed colonies

• Dependent on a sustainable source of honey bee colonies

Source of honey bee colonies• Either from wild (African, Europe or middle

east) or feral populations (Americas, Australia)

• Influence of beekeepers – may be colony multipliers (Europe, North America, Australia/New Zealand) and/or colony harvesters (Africa, Central and South America)

• Sustainability is dependent on the management of these two kinds of beekeeping strategies

Responsible colony harvesting for industrial farming & rural development

• Determine the size and fluctuations in the wild population.

• Variation in relation to climate

• Determine safe levels of harvesting in various biomes

• Continuous monitoring of the state of the wild population to adjust harvesting levels.

Estimation of honeybee populations densities

• Effective population size of social insects is determined by colony density or number of reproductively active queens

• Finding and counting colonies is very difficult because they are cryptic –so alternative estimation methods required

• Drone ‘trapping’ through virgin queens and

analysis of their offspring.

• Direct drone trapping with Williams drone traps

Kinds of honey bee colonies

• Wild colonies – unmanaged colonies in an areawhere honey bees are indigenous

• Managed colonies in apiaries –queen breeding • Feral colonies – colonies escaped from apiaries

and living freely

Drone Trapping

43

William’s Trap

South African Biomes

Proposal for a Survey of the South African honey bee populations

• Get a consortium of the three universities undertaking honey bee research and the ARC to plan and undertaken the work

• A number of sampling sites in each of the South African biomes will be identified and samples taken 3 times a year for three successive years.

• The results will provide a rough estimate of the size of the wild honey bee population, its sensitivity to climate variability and its dynamics.

• Will provide for realistic estimates of the potential for both professional and developmental beekeeping at particular sites.

Acknowledgements

Estimation of honeybee colony Densities using drones & workers

Sampling area is almost twice as large using workers than drones. Effect of queen mating flights.

Both methods suitable for estimating colony densities. Drone trapping gives superior precision.

Tswalu experiment – 47.2 colonies from worker sample26.5 colonies from drone sample.5.7 colonies /km2 -drones

Moritz, Dietemann and Crewe, J. Insect Conservation 12:455 -459 (2008).

Temporal variation in colony presence at Ezemvelo

Temporal dynamics studied in a nature reserve unaffected by the influence of beekeeping activities. 

80% of drone contributing queens were replaced in successive 8 month periods. 

The effect of this high turnover is high genetic diversity, boosting effective population size and hence maintaining genetic diversity.

Jaffe et al. 2009 Molecular Ecology

• Large wild population ≈ 10 million colonies, small proportion ‘managed’ in apiaries

• Two subspecies– Apis mellifera capensis and – Apis mellifera scutellata

• All major honey bee diseases & parasites present– Varroa mites– Viruses– American foulbrood– Capensis problem (social parasites)

South African situation

• Large wild population –unknown size, very small proportion ‘managed’ in apiaries

• Four subspecies– Apis mellifera litorea– Apis mellifera scutellata– Apis mellifera monticola– Apis mellifera yemenitica

• All major honey bee diseases & parasites present– Varroa mites– Viruses– Nosema

Kenyan situation

Kenyan situation

Muli E, Patch H, Frazier M, Frazier J, Torto B, et al. (2014) PLoS ONE 9(4): e94459.

Key behavioural traits of African Honey bees

• Migratory swarms resulting from seasonal abundance of food

• Absconding in response to disease/disturbance • Faster generation times and smaller colonies

Drone ‘trapping’ by queens

Estimation of honeybee colony Densities using Drones

Figure 1 : Sex determination in hymenoptera.Genotypes and sexual fate under the system of complementary sex determination found in many hymenopteranspecies (ants, bees, wasps, sawflies). Males derive from unfertilized eggs and have only one sex determinationallele (marked by different colored bars). Fertilized eggs with two different sex-determining alleles(heterozygous) develop into females. Diploid males arise from fertilized eggs that are homozygous for the samesex-determining allele. These diploid males arise most commonly under inbreeding conditions in which thefather has an allele in common with the mother.© 2009 Nature Education All rights reserved.

http://www.nature.com/scitable/resource?action=showFullIm...

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Estimation of honeybee colony Densities in Germany & SA

African populations 12.4 – 17.6 colonies/ km2 analysis of dronesEuropean populations 2.4-3.2 colonies/ km2 analysis of workers

1. Ezemvelo, 2 Leeufontein and 3 SuikerbosrandMortiz et al. J. Insect Conservation 11, 391- 397 (2007)

Temporal variation in colony presence at Evemvelo

Jaffe et al. Molecular Ecology 11: 1511-1522 (2009)

Colony losses in South Afrcia

• Absconding – 52%• Vandalism – 46%• Honey badgers & ants – 30% • Capensis social parasite – 26%• Fire – 28%

Floods & veldfires

VandalismFloods

Veld fires

Removal of forage trees

Conclusions• Beekeepers in South Africa colony losses are largely

not attributable to diseases, pesticides or parasites• Losses are caused by behaviour of the bees and the

actions of beekeepers– Absconding which is not a loss to the population of colonies– capensis social parasite specific to SA

• Losses made up from trapping colonies from wild population of honeybees as opposed to breeding of colonies as in Europe.

Future• More extensive honeybee surveys across SA to

determine colony densities on a finer scale• Long term monitoring of these sites to determine

the effects of – Changes in land utilization – Harvesting of honeybee populations by beekeepers– Effects of diseases – Effects of pesticides

Losses scutellata > capensis

Average percentages of colony losses

2009/2010 2010/2011 2011/2012 2012/20130

5

10

15

20

25

30

35

40

45

50Scutellata

Capensis

Overall

colo

ny lo

sse

s %

Effect of migrating (2011/2012 – 2012/2013)

Significant for A. m. scutellata and for A. m. capensis – different responses to queen loss.

Scutellata Capensis Overall0

10

20

30

40

50

60Migration Stationary Hobby/SM

Commercial

colo

ny lo

sse

s %

Honeybadgers Monkeys

Kinds of honey bee colonies

• Wild colonies – unmanaged colonies in an areawhere honey bees are indigenous

• Managed colonies in apiaries –queen breeding, management of colonies, pollination

• Feral colonies – colonies escaped from apiaries

and living freely.

Neumann & Carreck 2010

Potts et al 2010

Status: 2010Status: 2010

47

Parasitic Cape honey bee worker in scutellata colony

Primary cause of losses

• Absconding – 52%• Vandalism – 46%• Honey badgers & ants – 30% • Capensis social parasite – 26%• Fire – 28%

49

Distribution of South African subspecies of honeybees

Vaudo et al. J Insect Cons. 2012

scutellata

capensis

50

Origin of Cape worker social parasitism

51

Development of a single family of social parasites

52

Effect on colony survival of beekeeping activites

53

Capensis infestation of Colonies

54

Conflict over Reproduction

55

Conflict over Reproduction

✦ Complete sterility of workers in eusocial colonies is rare

✦ Conflict over reproduction between: Queens & workers Workers for chance to reproduce Workers over rearing of brood✦ Apparent harmony is a consequence of

temporary resolution of conflicts✦ When relationships amongst individuals are

disturbed then strong conflict emerges

56

Capensis worker reproduction

✦ Workers rarely reproduce in presence of own queens

✦ Workers reproduce –lay diploid eggs that produce females – mainly workers

✦ In own colony - leads to laying worker headed colonies

✦ In other colonies: ✦ capensis – self social parasitism ✦ scutellata - social parasitism and

colony loss

• Working Group Monitoring and Diagnosis - investigating colony losses

• Standardised protocol for collecting data - allow for comparisons

COLOSS Network

Monitoring & Diagnosis

Pests & Pathgens

Country Losses

Algeria 13.45Austria 17.2Bosnia and Herzegovina

6.18

Croatia 9.52Denmark 20.91Estonia 25.53Finland 17.02Germany 15.39

Ireland 37.08Israel 5.9Italy (Veneto region) 12.2Latvia 19.65Netherlands 13.71Norway 18.15Poland 18.11Scotland 31.06Slovakia 9.13Sweden 22.62

losses 31% (USA) and 34% (UK)

Honey Bee Colony Losses Winter 2012-13

• “Losses remain greater than beekeepers consider acceptable” (2013 COLOSS press release)

• Explanations remain elusive• Several possible causative factors: both alone and in combination

– pesticides, – poor nutrition, – beekeeping management practices, – pests and diseases,

Global perspective

2011/2012 Questionnaire: Colony losses in South Africa

• Limited knowledge about colony losses• Aim of questionnaires to

• quantify colony losses • identify potential causes and threats• collect comparable data - standardised protocol

 Which of the following reasons would you give for your colony losses? How many colonies were lost to this reason?

Yes/ No # ColoniesAbsconding    Bad beekeeping    Bad weather / lack of forage/ drought    Capensis bees    Diseases    Fire    Honey badger / ants    Insecticides / poisoning    

Pollination stress     Small hive beetles     Vandalism / theft    

Added for country specific situation

Diseases and parasites present

• Varroa• Small hive beetle• Wax moth• European foul brood• American foul brood• Nosema apis• Chalkbrood• Viruses

capensis social parasite

• Remains a major problem in scutellata area– problem can be overcome using good beekeeping

practices

Increasing number of colony losses

Crop effects

Reported losses not significantly different from no losses

0

10

20

30

40

50

YesNoLO

SSES

(%)

Significantly more colony losses on these crops

Apples/Cherries Eucalyptus Onions Sunflowers0

10

20

30

40

50

60

YesNo

LOSS

ES (%

)

• Large wild population -14-18 million managed colonies (small proportion)

• Two subspecies– Apis mellifera capensis– A. m. scutellata

• All major honey bee diseases & parasites present– Varroa mites– American foulbrood– Capensis problem

South African situation

Bad beekeeping practises

Unsafe apiary sites

Perceived causes 2009/2011 2011/2013

• small hive beetle• Varroa • Absconding

(loss to beekeepers not bee population)

• chalkbrood• Capensis social parasite

• Vandalism & Absconding• ants• Bad weather & honey

badger • fire• Capensis social parasite

Colony losses-South African data?

0

10000

20000

30000

40000

50000

60000

70000

80000

FAO data SOUTH AFRICA

Years

Thou

sand

s of

col

onie

s

Trend

• After 20 years still a major problem in Scutellata areas– beekeeping practices to blame– problem in the Cape to a lesser degree?

• Number of colony losses increasing? Catching more infested swarms

Is it wise to consider the wild bee population as an inexhaustible resource for restocking ?

Average colony losses

2009/2010 2010/20110

5

10

15

20

25

30

35

20.6

28.6

Loss

es (%

)

Higher losses with scutellata (29.1%) than capensis (17.9%)

Effect of migrating (combined data)

Migratory beekeepers Stationary beekeepers05

10

1520

25

3035

4035.5

17.2

Loss

es (%

)

Only significant for beekeepers using A. m. scutellata, but not A. m. capensis, in their operations

Effect of migrating (2009/2010 – 2010/2011)

Only significant for A. m. scutellata, not for A. m. capensis

Crop effects

No significant differences between losses

Losses significantly higher on these crops

Wild honeybees can buffer some losses, but they also make an epidemic disease a serious ecological and economical issue if they came to be threatened

• Questionnaire Results will be published in JAR• All participants will be updated

Information on losses:• [email protected] • US http://

beeinformed.org/2013/05/winter-loss-survey-2012-2013

• UK http://www.bbka.org.uk/files/pressreleases/bbka_release_winter_survival_survey_13_june_2013_1371062171

• Questionnaire developed over 3 years• 20 countries part of this group• All questions well thought through

• Global decline in honey bee numbers (managed & feral colonies) – great concern – received attention

• Exceptional colony losses not unusual • Multiple records over 100 years

– early 1900s Isle of Wight 90% of bees lost – 1910 Australia lost 59% of colonies – 1915-1917 USA and Canada– 2002-2003 Sweden, Germany– 2006-2007 USA

• No definite cause, only speculation• An event or part of a cycle of disappearance?• RSA loss to beekeepers not bee population

Fact or fiction?

RESULTS• Biggest problem is the return rate

– 2013 data from 19 European countries• 15000 beekeepers and 280 000 colonies

– USA • 6,287 beekeepers managing 599,610 colonies, (22.9%)

– RSA for both seasons 95 beekeepers and 23 355 colonies (4%)

http://www.southafrica.to/provinces/RSA_by_provinces.jpg

35

5

3

4

3

1

27

4