Why we need bees - University of Maryland, College …...Why we need bees Lisa Kuder PhD student, UMD Importance of Bee Pollination With and without bees Whole Foods & Xerces $15-18
Post on 23-May-2020
4 Views
Preview:
Transcript
$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
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!
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
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.
• 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
http://www.beemaster.com/forum/index.php?topic=16877.0
Cane, JH USDA-ARS (2015) Gardening and Landscaping Practices for Nesting Native Bees
• 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
http://www.beemaster.com/forum/index.php?topic=16877.0
Cane, JH USDA-ARS (2015) Gardening and Landscaping Practices for Nesting Native Bees
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?
http://www.beemaster.com/forum/index.php?topic=16877.0
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
top related