GainesDay arboretum-bee-talk-4-7-14

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)

Hannah Gaines Dayhgaines@gmail.com

774-392-0498