Robyn McCallum presents at the 2015 Acorn Conference

1. Habitat Management
for Native Pollinators
(and Natural Enemies)
Robyn McCallum, Nancy McLean and Chris Cutler
November 2015
ACORN

2. How can we enhance
agroecosystems?

5. Outline
• What is habitat management?
• How does it work?
• What are some benefits of habitat management?
• Native pollinators in Atlantic Canada
• Natural enemies
• Biology
• Their needs
• How do we start thinking like them?

6. What are Native Pollinators?

7. Wild Bees
• ~ 200 different bees in NS
• ~ 900 different bees in Canada
• ~ 20,000 worldwide

8. Bumble bees (Bombus)

9. Halictids
Image from entnemdept.ufl.edu
Image from discoverlife.org

10. Andrenids
Image from
naturespot.org.uk
Image form bee-busy.com

11. Megachilids
Images from bugguide.net

12. Apidae
Image from beneficialbugs.org

13. Managed Pollinators
• Honey Bees
• Alfalfa Leafcutter Bees
• Bumble bees

14. Why are native pollinators
important?
• conservation
• ‘insurance policy’
• free services- food and
plant biodiversity
• challenges facing
managed bees
• efficient & effective
• buzz pollination

15. VS

16. What are natural
enemies?
• beneficial insects,
parasitoids, predators
• Involved in pest control
• E.g. beetles, wasps
• Similar needs as pollinators

17. Why are natural enemies
important?
• Biological control
• Dual purpose- pollination
• Nature takes care of itself
Image from
atlanticpestsolutions.net
Image from ipm.iastate.edu

18. Native Bee Biology

19. Solitary vs Social Bees
• Most bees are solitary
• Cavity nesting, ground nesting
• Some are social
- Honey bees ! hives
- Bumble bees ! rodent holes

20. Nesting
• Trees, stems, reeds,
under rocks, in old
cars, in roof eaves,
milk cartons
• Proximity of water
• Parasites- nesting
aggregation
• Soil tillage

22. Food
• Typically pollen & nectar from flowers, but also oils
• Specialists vs generalists

23. How can we manage
nesting?
• Tubes for cavity-nesters
• Soil conditions for
ground-nesters

24. How can we manage food?
• Floral plantings along field edge
• Marginal land, ditches, etc have also been used
• Provides habitat in addition to food at valuable
times

25. • Annual and perennial wildflowers
• Growing interest in “native flowers”
• Important to have diversity of flowers- tongue
length, nectar rewards

26. • Important to note that bees and other pollinators need
food throughout the season- before and after crop
bloom

27. Nutrition

28. Foraging Range
• Depends on body size,
species
• Affects foraging & access to
flowers
• Ranges from ~100 m to 5 km

29. Emergence, Phenology
• Spring vs later in the season
• Varying adult life spans- weeks to months to years
• What happens if required flowers aren’t blooming at
the right time? Climate change? Evolution? Tongue
length example

30. Development
• Bumble bees vs solitary bees

31. How do we think like bees?
• What are basic needs? Food, water,
habitat

32. Habitat Management
• Conservation biology ! improve
availability of resources (Landis et al. 2000)
• Connecting habitat mgmt with pollinator
abundance and crop yield ?
• Apple & highbush blueberry studies

33. Habitat Management
Potential benefits include:
Alternative or
complement to
managed bees
Increased
biodiversity
Increased
biological
control

34. What Drives Conservation
Biology?
Economic
Factors
Conservation
Concerns

35. What do I plant?
• Annuals & Perennials
• Different bloom times
• Different flower structures

36. • Red clover, alfalfa, sweet clover, buckwheat, black eyed
susan, vetch, sunflowers
• Wild roses, goldenrod, St. John’s Wort
• Phacelia? Wild bergamot?
• Spring-flowering trees (willow, etc.)
• Takes time- both plant and bee establishment

37. Soil Prep
• pH **
• Tillage
• Habitat disturbance risks- mitigate with perennials

38. On-Farm Techniques
• Weeds for food- balancing act
• Woodpiles for habitat
• Setting aside poor land for flowers
• Pollinator gardens

39. Public Concern for Native
Pollinators
• Population decline?
• Pesticides?
• Pathogen spillover from managed hives (or vice
versa??)
• Lack of habitat **
• Lack of food (flowers) **

40. Enhancing Native Pollinators and
Natural Enemies in Wild
Blueberry Agroecosystems

41. • Many crops require pollinators for fruit set
• Pollinator services from managed bees = high input
costs
• Native pollinators are efficient, effective and already
present (Javorek et al. 2002)
Background

42. • Native pollinators provide
important ‘free’ services
• Populations could be
increased to become more
economically important

43. Lowbush Blueberry
• Requires cross pollination
• Pollination services can be #1 cost (honey bees, other
managed bees)
• Unique cropping system (crop vs sprout)
• Opportunity to enhance agroecosystem for pollinators

45. • Techniques to boost native
pollinators & natural enemies
• Focused on habitat and food
Objectives

46. Habitat
Trap nests Clay lids
Food
Buckwheat Operation Pollinator

47. Buckwheat
• Can we plant buckwheat around the field to provide
food after blueberry bloom?

48. Buckwheat
• Annual
• Can tolerate low pH
• Tolerates poor soil fertility
• Improves soil structure
• Doesn’t spread
• Attractive to bees
• Long blooming period
• Used for honey bees

49. Buckwheat

50. Data Collection

51. Buckwheat results so far

52. Challenges
• Producer inputs
!tillage, seed, management (no spray), need to plant
each year, perhaps 2x per season
• Drought
• Deer
• Economic benefits?
• Conservation benefits?

53. Habitat
Trap nests Clay lids
Food
Buckwheat Operation Pollinator

54. Operation Pollinator
• Mixture of annuals and perennials
• Can we measure nectar content?
• What is persistence like, weed invasion, etc?

58. Habitat
Trap nests Clay lids
Food
Buckwheat Operation Pollinator

59. • Trap nests for Osmia species (Hymenoptera:
Megachilidae)
• Cavity-nesting bee, readily accepts artificial nests
• Known to be good pollinators
Habitat Management for Mason Bees

60. • Solitary
• 8-9 species involved in blueberry (Stubbs et al. 1997)
• Queen lays eggs on pollen provision, larva ! pupa !
emerges the next year (Torchio 1989; Bosch et al. 2001)
• Linear sequence of ‘cells’
Osmia Biology

61. • Adult life span! 3- 5 weeks
• Can fly @ low temps and emerge early in season
• Need mud to ‘cap’ their nests, so water source important
Osmia Biology
www.bugguide.net

62. • What species are involved?
• Does nesting uptake differ from crop field
to sprout field?
• When does nesting occur?
• Are nests parasitized?
Questions

63. • 80 trap nests in 4 fields (64 wooden, 16
milk cartons)
• Placed 10 m apart along field edge
and facing the sun, supported on
stakes
• Set out 22 April in crop fields in
northeastern Nova Scotia
Materials & Methods- 2014

64. Wooden Trap Nests
• Examined different hole
diameters, rain cover,
burning
• Tubes were 10 cm deep

65. • 12 tubes/ 2L carton
• Tubes = 15 cm long
• Varying diameters (7 and 9 mm)
• Tubes from rolled white paper + newspaper and placed
through high-density polystyrene foam; spray foam
insulation to support tubes (Sheffield et al. 2007)
• Cartons painted white
Milk Cartons

66. Results 2014
Nesting Success
%
Success
0
18
35
53
70
Nest Type
milk carton wooden
• n =
n = 14

67. • Focused on milk cartons only
• Compared crop and sprout
Materials & Methods-
2015

68. • Modified design
• 16 tubes instead of 12
• All the same diameter (7 mm)
• Added plastic straws
Milk Cartons- 2015

69. • 26/32 milk cartons had capped nests (81%)
• 4 milk cartons were removed due to bear
damage
Results & Discussion-
2015

70. Question: Crop vs Sprout
• No significant difference
• Trade offs for nearby
crop/sprout rotations
(bees & pests)

71. Question: Timing
Phenology of Osmia Nesting in 2015
Total#CappedNests
0
35
70
105
140
Date
12-Jun 26-Jun 1-Jul 10-Jul 17-Jul 22-Jul 31-Jul
• Blueberry Bloom

72. Question: Timing
• Capped nests appeared
after blueberry bloom had
finished
• Not all tubes were capped
at the ends
• Queens likely nested in
more than one tube

73. • TBD, as well as species
of Osmia
Question: Parasitism

74. • Why are milk cartons attractive?
-Longer tubes
-Smell?
-Pink Styrofoam? White carton?
• Landscape factors- water sources, previous populations,
food throughout season
Discussion 2015

75. Implications for Industry &
Science
• Better understanding of Osmia nesting
biology & involvement in wild blueberry
• Nests could be moved to crop fields
requiring pollinators
• Practical, inexpensive technique

76. Implications for Industry
& Science
• More efficient pollination
• Biodiversity conservation
• Alternative & complement to managed bees

77. Diversity of pollinators demands a diversity of habitat
management techniques

78. Global Importance
• $ for farmers in Europe who implement
bee-friendly practices
• Marketing strategy for US farms “bee
friendly farms”
• “bee friendly” product labeling

79. Community Engagement
• Fact sheets for blueberry production
• OP seed mix fact sheet
• 4H pollinator project development
• Grower field days
• Industry meetings
• Schools
• Garden Clubs

80. Agvocate Challenge
• We need more positive ag stories!
• First blossom, bees, tractors, people
• Use opportunity to share

82. Resources
• Lawrence Packer Lab, York
University
• Sheila Colla- online resources
• Nova Scotia Dept of Ag handout
re: bees
• Discover Life
• Bug Guide

83. Acknowledgements
Committee Members
Dr. Paul Hoekstra, Syngenta
Blueberry Producers of NS for Field Sites
Snake Patrol

84. Robyn McCallum
Robyn.mccallum@dal.ca
@mccallumrobyn
Questions?