christelle guédot department of entomology the blue orchard bee: a native managed pollinator
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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