why we need bees - university of maryland, college …...why we need bees lisa kuder phd student,...

Why we need bees

Lisa Kuder

PhD student, UMD

Importance of Bee Pollination

With and without bees

Whole Foods & Xerces

$15-18 billion nationwide $216 billion worldwide, or about 10% of the total value of the world agricultural food production (2008)

The economic ranking of cattle, pigs, honey bees and poultry (from The Buzz about Bees, J Tautz and H Heilmann, Springer, Heidelberg 2008)

Value of Bees

Overall Wild Insects More Efficient

Garibaldi et al. 2013

Increasing Importance

Aizen, MA; Garibaldi, LA; Cunningham, SA; Klein, AM (2008) Long-Term Global Trends in Crop Yield and Production Reveal No Current Pollination Shortage but Increasing Pollinator Dependency. Current Biology, 18(20): 1572–1575.

In 2015, 7.3 billion people!

Wild Plants Need Bees Too

80%

Who are the pollinators?

Primary Pollinators

pollen basket

Source: Distant Hill Gardens

Bee Tools

http://honeylove.org/ha_pollencollecting/

– Bees don’t see red

– Visual range extends to UV

– Bull's-eye view

– Also see iridescence

A Bee’s View

Very effective!

Moisset and Buchmann 2011

Long vs. short corrola

If the Tongue Fits

Life cycle of a solitary bee: 1) egg, 2) larva, 3) pupa and 4) adult. Solitary adult bees provision their young with a pollen-ball, illustrated above.

Image credit: http://www.xerces.org/pollinator-conservation/native-bees/

Solitary Bee Life Cycle

• Bare patches of soil (~70%) Narrow tunnels leading to sm.

chambers

6 – 36” below the surface

• Wood and pithy stems (~30%) Hollow tunnels in stems of twigs

Holes often left behind by larvae of other insects

Rotting logs and stumps

USDA Agroforestry 2007

Where Do Native Bees Live?

Photo credit: https://www.arkwildlife.co.uk/Image/600/600/JPG/WILDLIFE%20HABITATS-FS-BEES-FS-MASON_BEE_NEST.jpeg

Cavity Nesting Bees

• Remaining bees(~1%) Social bumble bees

45 species in the U.S.

Excellent pollinators!

Nest sites: • Cavities

• Old rodent burrows

• Underground or beneath fallen plant matter

• Rarely in birds’ nests

USDA Agroforestry 2007

Wild Social Bees

• BBs will sting only if their hive is threatened

• Solitary bees are gentle and do not protect their nests

• Accidental stings

• On pain scale -- low

The Xerces Society 2014

Do Wild Bees Sting?

• Not certain; Long-term data lacking

• Recent field studies indicate decreases [1, 2]

• In 2010, USGS began funding a systematic count of native

• Specimens from 140-yr span show persistence of natives but major decreases in relative abundance [3]

[1] Potts et al. 2010, [2] Vanbergen et al. 2013, [3] Bartomeus et al. 2013

Status of Native Bees

What is Killing the Bees?

Parasites

Pathogens

Pesticides

Poor Nutrition

Habitat destruction

Mono- cultures

Parasites: Varroa destructor

• Parasite that causes biggest economic impact

• Transmit viruses: ABPV and DWV

• Can only reproduce on honey bees

• Acceptable limit: 3/100 bees

• Resistance to treatment

Neonics Alter Honey Bee Immune System

Di Prisco, Gennaro, et al. "Neonicotinoid clothianidin adversely affects insect immunity and promotes replication of a viral pathogen in honey bees." Proceedings of the National Academy of Sciences 110.46 (2013): 18466-18471.

• Causal link betw/ 2 neonics and altered HB immunity

• Negatively affects a protein that modulates immune signaling

• Antiviral defenses reduced

• Promotes replication of DWV

• Conclusion: sublethal effects of neonics induced viral proliferation in the lab

Organophosphate

Neonics Adversely Affect Wild Bees

Rundlöf, Maj, et al. "Seed coating with a neonicotinoid insecticide negatively affects wild bees." Nature 521.7550 (2015): 77-80.

Seed-coating treatment affected

bumblebee colony development

O. bicornis

July 1, 2014

Home Depot to Require Neonicotinoids Labeling

Read more: http://www.environmentalleader.com/2014/07/01/home-depot-to-require-neonicotinoids-

labeling/#ixzz3eM8v6KY0

Retailer Support

http://www.beecityusa.org/newsevents/category/pesticides

Fungicide Exposure Harms Bumble Bees

Bernauer, Olivia M., Hannah R. Gaines-Day, and Shawn A. Steffan. "Colonies of Bumble Bees (Bombus impatiens) Produce Fewer Workers, Less Bee Biomass, and Have Smaller Mother Queens Following Fungicide Exposure." Insects 6.2 (2015): 478-488.

Nutritional Deficits

http://www.nextnature.net/tag/manufactured-landscapes/page/5/

http://madronoranch.com/?page_id=92&paged=4

Create Pollinator Habitat

Xerces.org

Avoid modern hybrids

Provide variety

Use native

plants

Blooms from early spring - fall

Plant in clumps

Planting Guidelines

Bees Prefer Native Plants Over Exotics

Morandin, Lora A., and Claire Kremen. "Bee preference for native versus exotic plants in restored agricultural hedgerows." Restoration Ecology 21.1 (2013): 26-32.

Specialists vs. Generalists

www.nature.com

• 57 bee species in NE visit only a few plant genera

• 32 plant genera host specialist bees

• Recommendation: – 1st target plant groups that

benefit specialist bees – 2nd fill in with more generic

floral groups that support generalist feeders

Fowler, Jarod and Sam Droege. “Native Plants for Specialist Bee Conservation in the Northeast.” Manuscript prepared 2015.

Specialist Bee Conservation

Andrena bracatta by S. Droege

Euthamia by Dirk

Solidago by Elfosium

• Primary components (8 – 50%) • glucose • sucrose • fructose

• Secondary ingredients • amino acids • phenolics • vitamins • organic acids • oils • free fatty acids • alkaloids

Source: Georgie Sharp http://www.d.umn.edu/~cjcarter/carterlab.html

Nectar Variation

•Goal: compare larval performance

on 5 exp.pollen diets

•Conclusions:

•Pollen mixing mitigates harmful

chemicals

•Optimizes larval food

Floral Variety = Healthier Bees

Eckhardt, Michael, et al. "Pollen mixing in pollen generalist solitary bees: a possible strategy to complement or mitigate unfavourable pollen properties?." Journal of Animal Ecology 83.3 (2014): 588-597.

R = Ranunculus (unfavorable

pollen)

Osmia cornuta Ranunculus acris

Pesticide Usage

http://www.beyondpesticides.org/pestici

defreelawns/pfzsign/

EPA’s ‘Citizen's Guide to Pest Control and Pesticide Safety’

epa.gov

Twig, Stem & Wood Nesting

Dead hollow twigs

http://www.beemaster.com/forum/index.php?topic=16877.0

Cane, JH USDA-ARS (2015) Gardening and Landscaping Practices for Nesting Native Bees

Emergence holes of beetles used as

nesting sites by many bees

Pruning w/ Bees in Mind



• Shrubs w/ hollow or pithy

stems can make excellent

nesting substrates

• Leave a 1’ long stub

• Timing may be important

• Bees that nest in stems:

Osmia, Hoplitis and small

carpenter bees (genus:

Ceratina)

http://www.dynamicearthlawncare.com/spring-landscaping/

Ceratina sp. by el.gritche

Attractive Nesting Substrates

Pebble mulch Leave bare ground



Landscape Practices to Minimize

Weed barrier fabric

Sprinkler irrigation during the day

Thick mulch Cane, JH USDA-ARS (2015) Gardening and

Landscaping Practices for Nesting Native Bees

Artificial Bee Abodes

http://www.dailymail.co.uk/travel/article-2639446/Guests-swarm-bee-hotel-

London-offering-day-trips-Buckingham-Palace-humans-stay-too.html

Amazon.com

Bee Hotels – An Effective Conservation Method?


MacIvor, J. Scott, and Laurence Packer. "'Bee hotels' as tools for native pollinator conservation: a premature verdict?." PloS one 10.3 (2015): e0122126.

•Toronto based study

• 2011 – 2013

• +27,000 insects/574 bee hotels

•Results

• 38% native wasps, 28% native bees

• Parasites infected native bees more often

•Conclusions

• Can facilitate parasites and disease

• Some locations more inviting to native bees

• Natural materials and design may help

Bee Hotels Lead to Positive Attitudes

Helgers, R. (2015). "Children’s Attitudes towards Bees: the effect of a Bee Hotel that reveals the bee’s activities."

Control group Commercial bee hotel Smart bee hotel

Traditional and smart bee hotels had a positively

significant influence on the attitude of elementary kids

toward bees compared to the CG

In Closing . . .

• Honey bees and wild bees perform invaluable

ecosystem services

• Many bee species appear to be on the decline

• Multiple drivers of decline >> synergistic effects

• You can help by creating pollinator friendly

habitats

The End . . . Any Questions?

why we need bees - university of maryland, college …...why we need bees lisa kuder phd student,...

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