gainesday arboretum-bee-talk-4-7-14
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The Buzz with Bees: Native and Managed
Pollinators
Hannah Gaines DayDepartment of Entomology
University of Wisconsin, Madison
Protecting wildlife through the conservation of invertebrates and their habitat since 1971.
Major Programs: • Endangered species • Aquatic invertebrates• Pollinator conservation
www.funet.fi
Advocacy, Education, Restoration, and Applied Research
Outline
• The importance of pollinators• Biology and natural history of bees• Resource requirements of native
bees• Crop pollination by bees• Threats to native bees• Native bee research at UW• Native bee conservation strategies
Pollination
• Transfer of pollen from anthers to stigma
• Wind, gravity, or animal mediated
© Bruce Newhouse
Pollinators
• Birds, bats, bees, moths, butterflies
Pollinators
• Birds, bats, bees, moths, butterflies• Bees are the MOST IMPORTANT
pollinators– Actively collect pollen– Floral constancy– Branched hairs
• 85% of all flowering plants • 35% of global crop production
R. Winfree
How important are bees?
Poor fruit set resulting from poor pollination
One in every three bites you eat is dependent on insect pollination.
What is a bee?
• Hymenoptera– Ants, bees, wasps
•6 legs, 4 wings• Vegetarian
– Provision nests with pollen
• Great pollinators!– Pollen sticks to
feather-like hairs
Bees versus wasps
• Carnivorous• Simple hairs• More aggressive• Examples: yellow
jackets, hornets, paper wasps
Bees versus flies
• Feed on decaying matter, feces, and blood
• Also feed on nectar • 2 wings, short stubby
antennae• Prominent eyes• Examples: house flies,
hover flies
Native bees versus honey bees• Single, non-native species• Perennial colony with queen• Wax hives• Produce honey
Honey bees are not native, but• Generalist pollinators• “Easy” to manage• Work well with modern agricultural
system
How many bees are there?
• ~20,000 species worldwide• ~4000 species native to North
America• ~500 species native to Wisconsin
Photos: James Cane; Steve Javorek (Ag Canada); Edward S. Ross
Honey bee (Apis mellifera)
Bumble bee (Bombus edwardsii) Leafcutter bee (Megachile sp.)
Polyester bee (Colletes sp)
Photos: Bruce Newhouse; Edward S. Ross; Mace Vaughan; USDA-ARS/Jack Dykinga
Metallic sweat bee (Agapostemon sp.) Yellow-faced bee (Hylaeus sp.)
Mason bee (Osmia sp.) Sweat bee (Halictus sp.)
Metallic sweat bee (Agapostemon sp.)
Mason bee (Osmia sp.)
Sunflower bee (Svastra sp.)
Long-horned bee (Mellisodes sp.)
Photo: Bob Hammond, CSU Coop Ext
Photo: Bob Hammond, CSU Coop Ext
Carpenter bee (Xylocopa sp.)
Photo: Gene Barickman, IL NRCS
Photo: Stephen L. Buchmann
Social behavior of bees
• Solitary (majority of species)• Social (only 10%)
– Honey bees (NOT native)– Bumble bees
Solitary bee life cycleSpring
Summer
Fall
Winter
(Photos: Dennis Briggs)
Social bee life cycle (bumble bee)Spring
Summer
Fall
Winter
Nesting behavior of bees
GroundStem
S. Camarzine
Cavity
Ground nesting (~70% of bees)
P.Westrich
Ground nesting (~70% of bees)
K. Ullmann
© Edward Ross
Stem nesting (~30% of bees)
www.pestweb.comwww.warrenphotographic.co.uk
Leaf-cutter bees (Megachile sp.)
Stem nesting bees
• Leaf-cutter bees (Megachile addenda)
Mud cap closure
Larva
Pupa
Adult
Pollen mass
Egg
Mud wall
Cross-section of silk cocoons
Stem nesting bees
Stem nesting bees
www.agf.gov.bc.ca
T. Stoehr
• Mason bees (Osmia sp.)
S. Camarzine
Cavity nesting (bumble bees)
K. Ullmann
Cavity nesting (bumble bees)• 45 species in North America• Annual colony with 100-300 workers• Specialist pollinators of red clover,
blueberry, cranberry, eggplant, tomato
Photos:Eric Mader, Elaine Evans
Resource requirements
• Flower availability– Early spring through fall
• Nesting resources– Undisturbed soil, woody habitat, or nest
boxes
Landscapes
• Some landscapes already provide adequate resources.
A. Bennett
Landscapes
• Some do not.
A. Bennett
Why is the landscape important?• Central place foragers• Flight distance proportional to size of
bee
Crop pollination by bees
• One in every three bites…
Crop pollination by bees
Photo: USDA-ARS/Scott Bauer
US Agriculture
www.gallery.photo.net
Honey bee decline
• Mites, disease, Colony Collapse Disorder
Photo: USDA-ARS/Scott Bauer
Varroa mite
Causes of Colony Collapse Disorder• Disease/pathogen?• Israeli Acute
Paralysis Virus?• New strain of
Nosema?• Pests?• Poor diet?• Insecticide
exposure?• Stress?• Not cell phones or
Bt Corn
Honey bee rental rates (CA)
1995-2005
Honey bee rental rates (CA)
1995-2005, plus almonds, 2006-20082006
2007
2008
How does the honey bee decline effect Wisconsin farmers?• Hive fees increase• Hive quality decreases
Native bees and crop pollination• Active earlier in
season and day • Collect both pollen
and nectar• Buzz pollination• No rental fees• Keep honey bees
moving• Not susceptible to
honey bee diseases
Significance to agriculture
- Native bees provide insurance against honey bee decline
- Efficient crop pollinators
R. Winfree
Photo: Bob Hammond, CSU Coop Ext
Native bees and crop pollination• More efficient than honey bees• Active earlier and in cooler weather• Not effected by honey bee diseases• Free!
Native bees also in decline
© Derrick Ditchburn
© Johanna James-Heinz
© Jodi DeLong
© Peter Schroeder
Yellow-bandedFranklin’s
Rusty-patchWestern
Images: The Xerces Society
Native bees also in decline
- Yellow Banded Bumble Bee (Bombus terricolla) once very common, now gone
What threats do they face?
- Disease and pathogen from commercially reared bumble bees
- Agricultural intensification- Pesticide exposure- Loss of habitat
Bees and Wisconsin agriculture
Bee researchers at the UWBrian Spiesman
Rachel Mallinger David Lowenstein
Hannah Gaines Day
Native bees in cranberry
– 182 species of bees– More woodland = more bees
Cage Treatment
p = 0.007Y
ield
(bb
l/acr
e ±
SE
)
Closed Open
Native bees in apple
• ~80 species of bees• >50% of all visits to apple
flowers• Habitat diversity -> bee diversity
Native bees in apple
Native bees in cucumber
• 65 species• More natural habitat = more
bees
Native bees in grasslandMore flowers = more bees
Native bees in biofuels
Werling et al. PNAS 2013
Greater plant diversity = more bees, more pollination
Pollinators need habitat
Photo: Rollin Coville
How can you provide habitat?• Nesting resources • Floral resources
Nesting resources
• Artificial nest boxes
K. Ullmann
K. Ullmann
Photos: Matthew Shepherd; NRCS/Lynn Betts
Nesting resources
• Bare, undisturbed ground
Photo: Bob Hammond, CO Coop Ext
Nesting resources
• Natural habitat
© NRCS Lynn Betts © Mace Vaughan
Floral resources - diversity
Foraging resources - timing
TAXA APRIL MAY JUNE JULY AUG SEP OCT
Colletes (inaequalis, validis)Andrena
Augochlora pura
Augochlorella striataHalictus (females)
Lasioglossum (females)Osmia
Bombus © Data from Steve Javorek, Agriculture Canada
• Bee flight periods in Nova Scotia
Floral resources - timing
• Spring ephemerals
Floral resources
• Systemic pesticide use in commercial nurseries
Foraging resources
• How to select good bee plants– Locally native plants are better for
native bees– Minimum of 3 blooming plants at all
times throughout the season (spring, summer, fall)
– PLANT IN CLUMPS FOR BEST RESULT!
Protecting the bees• Restrict insecticide use
•Use active ingredients with least impact on bees
•Spray at night
•Consider alternatives
• Companion planting
• Pheromone traps and baits
•Restrict herbicide use
K. Ullmann
Native bee conservation
• Plant diverse floral plantings that bloom throughout the season
• Create and protect nesting sites (nest boxes, bare ground, natural areas)
• Limit chemical use in your garden AND ask at the nursery where you buy plants if plants have been treated with SYSTEMIC pesticides
Take home message
• Bees are important– 1 in 3 bites you eat depends on bees!
• Relying on a single pollinator species is risky– Decline threatens our food supply
• Plant flowers!
Further resources
The Xerces Society (www.xerces.org)
Further resources
The Xerces Society (www.xerces.org)– Pollinator Conservation Resource
Center•Plant lists•Conservation
guidelines•Pesticide
guidelines
Further resources
Insect identification• Bug Guide (www.bugguide.net)• Discover Life (www.discoverlife.org)
