Christelle Guédot Department of Entomology The blue orchard bee: A native managed pollinator.

Christelle GuédotDepartment of Entomology

The blue orchard bee:

A native managed pollinator

Most important insect pollinators: Bees

1. Feed on nectar and pollen2. Pollen collecting structures (scopa, corbicula)3. Display floral constancy (strong tendency to visit flowers of the

same type on a single foraging trip): important for pollination because minimizes pollen wastage and stigma clogging with pollen from other species

Wikimedia Commons

Andrena

http://www.natures-desktop.com/images/wallpapers/1600x1200/insects/bee-collecting-pollen.jpg

Osmia bicornis

Jeremy Early

pollinator.info

John B. Pascarella, Sam Houston State University

Why are bees important?

Whole foods and Xerces Society "Share the Buzz" campaign (2013)

• At least 25,000 known species of bees

• Social vs. solitary, 90% being solitary

• ~4,500 of solitary spp. in North America

• Wisconsin: ~390 spp. (Wolf and Ascher, 2008)

Bees

NativeExotic

T'ai Roulston, University of Virginia

Stephen Buchmann

Smallest North American bee (Perdita minima) on largest female carpenter bee

Bees: distinguishing characteristics

Bees vs. WaspsRobust SlenderHairy SmoothFlat rear legs Slender legsFeed on nectar and pollen Predators

James Canemommammia Flickr

Photos: Dennis Briggs

Mining bee (Andrena sp.): a year in its underground nest as egg, larva, and pupa before emerging to spend a few weeks as an adult.

Life cycle of a solitary bee

~70% of native bee species nest underground

• Resemble ant-nests from above ground

• Nests may be as deep as 3’

Ground-nesting solitary bees

Photos: Eric Mader, Matthew Shepherd, Dennis Briggs

Photos: Edward Ross, Darrin O’Brien, Matthew Shepherd

~30% of native species nest in cavities• Nest in hollow plant stems, old beetle borer holes,

man-made cavities • Nest have tunnel partitions constructed of mud, leaf pieces, or sawdust• Artificially managed for some crops

Cavity-nesting solitary bees

Impediments to bee pollination on fruit trees

- Early season; bad weather

- Short flowering period: 2-3 weeks

- Flowers receptive only few days

- Cool temperatures slow pollen germination

ovules might degenerate before fertilized

- Incompatibility: bees must move between inter-compatible

cultivars in different rows

Bees for fruit tree pollination

Christelle Guédot, UW-Madison

Flower morphology

♀ organ♂ organ

≡ Pistil

http://appleharvester.blogspot.com/2011/05/king-blossom.html

Apple pollination

• Pollinate king blossoms (first to open, produces larger fruit)

• Pollinate blossoms with large amount of compatible pollen for

high number of seeds, which relates to fruit size and shape

• Size of fruit affected by number fruit produced; thinning might

be required

Christelle Guédot, UW-Madison

• Osmia lignaria, a native• Solitary but gregarious• Nest in pre-existing cavities• Only females provision nest• Collect nectar and pollen for provision • Collect mud for nesting material

Back Front

Provision

EggCell1

Mud partitions

The blue orchard bee

The blue orchard bee

Females

Male Female0.4 - 0.6” long

Prepupa5th instar larva inside coccon

White pupa Black pupa Adult

April - MayLate March

Sept - MarchJuly - Aug

June

Life cycle of blue orchard bee

Eggs hatch, larvae grow into pupae

Dormant adults

Males smaller than more robust females

Males do not have scopa, females do

Males have longer, more slender antennae

Males have more facial hair

http://seabrookeleckie.com/

Identifying females vs. males

• Fecundity: 10 - 20 eggs / nesting female (2.5 - 6 ♀ eggs)

• Longevity adult females: ~20 days

• Females build ~ 2-4 nests in lifetime

• Emergence: - males emerge 24-48 hrs after warming

- females emerge 1-3 days later

Life history

• Native

• Commercial use in 1970’s

• Forages in cool weather > 54°F

• Visits many tree species:

almonds, apple, pear, cherry, apricot,…

Why the blue orchard bee?

discoverlife.org: Osmia lignaria distribution

Designed by The Polistes Corporation

Foraging behavior and pollination effectiveness

Almond Apple Pear

Osmia 98.7 97.7 98.7

Apis (P) 67.3 - 51.8

Apis (N) 39.5 32.7 19.0

% Stigma contact

Why the blue orchard bee?

Christelle Guédot, UW-Madison

http://www.ars.usda.gov/Research/docs.htm?docid=18333

• Blue orchard bees readily move from tree to tree and row to row

• Facilitate cross-pollination, rather than pollination within a tree or within a cultivar

• Preference for fruit tree pollen: 85-100%

http://www.swcoloradowildflowers.com

Golden currant

Dandelion

Why the blue orchard bee?

Why the blue orchard bee?

Active at low light levels and low temperatures

• 33+ hours foraging in 5 days

• 15+ hours by honey bees

Usual foraging range: 300-600 ft

Max. foraging range: 1,300 ft

Homing ability: 4,000 ft

Apple yield (bushel)

Apple Variety1977 + 1978Honey Bee

1979 + 1980Blue orchard bee

McIntosh 4380 5186Red Delicious 986 3248Golden Delicious 204 288Jonathan 430 417

Rome 184 307Total 6184 9446

Commercial Apple Orchard, Utah

53% increase

Apple yield with blue orchard bee

Year Pollinator Cherry yield (Kg) ♀ BOB increase

1992 Honeybee - -

1993 Honeybee 3,040 -

1994 Honeybee 5,545 -

1995 Honeybee 4,820 -

1996 Honeybee 3,695 -

1997 Honeybee - -

1998 Blue orchard bee 14,875 5.44

1999 Blue orchard bee 4,150* 2.17

2000 Blue orchard bee 16,935 4.21

2001 Blue orchard bee 4,415** 1.03

2002 Blue orchard bee -* 2.45

2003 Blue orchard bee 6,680*** 0.62

* Freezing event; ** missed timing on BOB release; ***high bee predation by birds

Why the blue orchard bee?

Commercial cherry orchard, Utah

Number of females

In comparison, need 1 - 2.5 honeybee hives / acre (typically 30,000 - 50,000 workers / hive)

Blue orchard bee Almond Apple

# nesting females/acre

300 250

# females/tree 3 2.5

Optimal number of nesting females for adequate pollination

Flower efficiency and fidelity

• 75 flowers per “load” of pollen and nectar

• 15-35 loads per provision

• 75 X 25 (avg.) = 1,875 flower visits per provision

• Female provisions 7 – 12 cells in her life

• A single female visits 10,000-20,000 flowers in her lifetime!

• Remember: 85-100% orchard flower pollen

Pollination efficiency

Christelle Guédot, UW-Madison

What do you need to haveblue orchard bees in your orchard?

• Care, attention, enthusiasm• Bee stock• Nesting equipment• Appropriate storage facility• Proper handling

http://www.sare.org/Learning-Center/Books/How-to-Manage-the-Blue-Orchard-Bee

How to manage the blue orchard bee

Where to obtain bees and materials

Nesting shelters

• Attach shelter on tree or fence post

• Orient SE for longer foraging

activity (and more attractive to

nesting females)

Shelter with wooden blocks and chicken wire

James Cane, USDA ARS

Nesting blocks

Prefer wood blocksPaper straws in cavities help for handling and storage

Reeds

Wafer boards

- 19/64” (7.5 mm) hole diameter

- 6” (15 cm) long

- Plan on 3-5 nesting cavities per female released

Nesting cavities

• Mud is a vital nesting material• Clayey mud, not sand or loam• Need safe place for gathering mud, within 20-50ft. of nest

Nesting material

Example for Northern Utah

1) March/April About two weeks prior to expected bloom:• Check flower development • Check weather forecast

A typical BOB season

2) March/April • Set up nesting materials and mud sources• Incubate bees at 72-76°F (22-25°C)• Emerged bees can be held at 37-41ºF for ~a week

A typical BOB season

3) March/April Release BOB population (200-300 females + 400-600 males per acre for full pollination in almonds, cherries, apples, and pears)

A typical BOB season

4) May/June Retrieve nesting materials• Move nests to summer storage (avoid excessive heat, direct sun)• Take measures to avoid parasitism

A typical BOB season

Blue orchard bee nests by black light trap Note large numbers of drowned Monodontomerus in tray Adult female chalcid wasp,

Melittobia chalybii

Adult female chalcid wasp, Monodontomerus

5) June through August

Monitor development with monthly development checks• Select 10 male cocoons from different nests

A typical BOB season

6) Mid/late September Move nests to winter storage (refrigerator)• Check small sample of females from different nests to be sure

that all adults • Best if population held for 1 week at 55°F before being placed

in artificial wintering at 39°F• Require minimum of 3 months wintering: adults go dormant

(diapause)

A typical BOB season

7) November/December • Quantify population• Remove parasites and diseased bees (now dead)• Prepare nesting materials for the following season

A typical BOB season

Recently emerged male covered with migratory nymphs of hairy-fingered miteChalkbrood fungus

Hairy-fingered pollen mite, Chaetodactylus krombeini

• Blue orchard beesare superb orchard pollinators

• BOBs can be usedalone or along withhoney bees

• Easy management• Bees are safe

Summary

Spray guide

• Jordi Bosch

• Theresa Pitts-Singer

• William P. Kemp

• USDA-ARS Beelab

Acknowledgements