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So excited to attend today's @XercesSociety Pollinator Short Course in Brooklyn flic.kr/p/2dAenSH
I'll try to take my notes via Twitter, so expect a tweet storm. (If I can't keep up that way, I'll switch to taking notes "offline".) Regardless, there'll be a new blog post coming out of today.
@XercesSociety #Pollinators
Materials provided with today's course:
@XercesSociety #Pollinators
More materials provided with today's course:
@XercesSociety #Pollinators
And we even get a copy of the book!
@XercesSociety #Pollinators
Speakers: Kelly Gill, Maria van Dyke
@XercesSociety #Pollinators
First up: Kelly Gill
Usually do this course in the summer, and get to go outside.
Intro to @XercesSociety. Kelly covers the Northeast.
Poster Child: Xerces blue butterfly, first butterfly species to go extinct due to human activity.
Also, @USDA_NRCS, working with farmers in the field, programs: Pollinators, Agricultural Biodiversity, Bee Better Certified, Bee City/Campus USA, others.
@XercesSociety #Pollinators
Part 1: The Importance of Pollinators
"Wildlife Conservation" equated with large mammals (Charismatic Megafauna)
Most described species are invertebrates. Insects alone > 50%.
Arthropods comprise 85% of mass of land animals.
@XercesSociety #Pollinators
"Ecosystem Services" (my scare quotes): Crop Pollination, Pest Suppression, Decomposition, Nutrient Recycling, Recreation (e.g.: insects feed birds, which people go out to see)
"We also have a responsibility to protect the intrinsic value." :-)
@XercesSociety #Pollinators
85% flowering plants, 35% global crop production, require animal, usually insect, to move pollen, especially in temperate regions.
Fruit and seeds, as well as insects themselves, feed other animals, including humans.
@XercesSociety #Pollinators
Pollinators visit flowers for food (and other stuff, I would think): pollen, nectar, or both.
Lifecycle matters: Diets change from immature to adult stages.
Wasps unusual among insects in that they provision nests.
Bees evolved from wasps.
@XercesSociety #Pollinators
Bees feed on floral products throughout their lives.
Bees exhibit floral constancy, learn how to collect pollen from specific flowers, visit the same flowers consecutively, efficient pollinators.
Need floral resources available near their nests.
@XercesSociety #Pollinators
"Honey Bees Are Not Typical Bees"
(Louder for the back:
Multiple generations per year. Perennial colony, overwinters. Honey production.
@XercesSociety #Pollinators
(Later will post my rant on honeybees)
Native bees: many different species, pollinator diversity.
No historical data for most species, can't tell if in decline or not.
Many groups: Andrenidae, Halictidae, Apidae, Megachilidae, Colletidae, and others.
@XercesSociety #Pollinators
Social bees, e.g.: bumble bees, are the exception among species.
Nesting: Hive/social (~1% species), ground (~70%), stem/wood (~%30%)
Most are ground-nesting, solitary bees, form aggregations where conditions favorable. (Like "my" cellophane bees)
@XercesSociety #Pollinators
(I have all three nesting types in my garden!)
Need diversity in pollinators.
Some species don't visit crop plants.
Plants need best match pollinators.
@XercesSociety #Pollinators
Examples: Tree fruit pollination.
Native bees, e.g.: bumblebees, mining bees, forage in cooler conditions less-preferred by honeybees.
Native bees contact the anthers and stigma more often, work "tops" of flowers.
@XercesSociety #Pollinators
Honeybees have two types of works, collect pollen OR nectar.
Pollen collectors only 3% of workers.
Nectar colelctors often bypass floral reproductive structures, go right for nectaries.
@XercesSociety #Pollinators
Buzz pollination, sonication, required by some flowers (~8% species) with "poricidal anthers".
Frequency: The "Hey" in "Hey, Jude". :-)
@XercesSociety #Pollinators
Pollen specialists, e.g.: squash bees.
Ground-nesting, typically at base of plants.
Flowers open early, bees visit, before other bees are active.
Can be widespread even across urban gardens and farms.
@XercesSociety #Pollinators
Wild plant pollination. ~30% of bees Mid-Atlantic/Northeast are pollen. specialists.
Many bees forest-associated, forest edge, up in canopies.
Specialization of mechanism: Bumblebees can open floral structures, e.g.: bottle gentian.
@XercesSociety @USDA_NRCS #Pollinators
Pollinator Status/Threats: Habitat loss, Pesticides, Disease, Invasive species, Competition, e.g.: honeybees (i,e,: livestock), Climate change
@XercesSociety @USDA_NRCS #Pollinators
Diseases can be concentrated in commercial raising of bumblebees.
Invasives: "But the bees are visiting". (Ecological traps, e.g.: butterfly bush "for the butterflies").
Climate: Warmer, asynchrony of emergence, bloom times, etc.
@XercesSociety @USDA_NRCS #Pollinators
Honey bees annual loss increasing in North America and Europe:
< 1995: 10-15%
1995-2006: 15-22%
2006+: 29-42%
@XercesSociety @USDA_NRCS #Pollinators
Bumblebees better-studied.
28% of our Bombus species are Endangered or Critically Endangered.
Once widely-distributed species now restricted in range, e.g.: rusty-patched bumblebee.
Possibly extinct: Franklin's bumblebee
@XercesSociety @USDA_NRCS #Pollinators
Butterflies in decline.
>17% N.A. butterflies Threatened or Endangered.
NY: 59 species of moths and butterflies need immediate action.
Monarchs (charismatic mesofauna)
@XercesSociety @USDA_NRCS #Pollinators
Monarchs: Habitat loss across the migration route, harder to manage.
"Quasi-extinction" (extirpation) high risk.
@XercesSociety @USDA_NRCS #Pollinators
Overall decline in wildlife populations.
1970-2010 (40 years) 52% drop of mammals, birds, amphibs, reptiles, fish, birds
NY: 145 species protected
@XercesSociety @USDA_NRCS #Pollinators
Q&A for Part 1

(Will start a new thread for Part 2. So go back to the pinned tweet to pick up that thread.)
@XercesSociety @USDA_NRCS #Pollinators
Up next: Maria van Dyke, Cornell Danforth Native Bee Lab
Part 2: "Think Like a Bee" - Native Bee Biology, Diversity, and Habitat Needs
@XercesSociety @CornellEnto #Pollinators
Life Goal: "What we're learning here today someday becomes common knowledge."
NY crops dependent on bee pollination: Blueberries, apples, legumes, squash, cherries, strawberries, ...
Wild bees better at pollination
@XercesSociety @CornellEnto #Pollinators
Effective pollination: better seed set, increased fruit set, better nutrition, taste, and appearance
Rare Plants: Corydalis caseana bardnegei (Rocky Mountains), depends on 2 bumblebee species
@XercesSociety @CornellEnto #Pollinators
Losing pollinator species locally leads to local extirpation of plant species
13% of NY's 416 species are in decline
(200-250 bee species found in NYC, not all native)
@XercesSociety @CornellEnto #Pollinators
AMNH Bee Database: 266 species collected across all 5 boroughs of NYC, 196 in Brooklyn alone
(Not all present necessarily today)
Central Park: 85 species
Prospect Park: 119 species
John Pickering, Discover Life
@XercesSociety @CornellEnto #Pollinators
Natural History of Bees
Proximity of Resources
Solitary- Social continuum
Solitary: Mating -> Nest-building, 35-40 foraging trips to provision to lay eggs for a single cell, flower proximity critical
@XercesSociety @CornellEnto #Pollinators
Aggregating bees: Still solitary, but nest close together. (Like "my" cellophane bees)
Semi-social bees: Start out solitary, one female becomes "alpha", sisters start foraging, can produce more nest cells than solitary
@XercesSociety @CornellEnto #Pollinators
Eusocial: Bumblebees, start out solitary, start laying eggs, eggs mature quickly, have workers to forage, queen stays in nest thereafter
Social: Honeybees, queen never leaves the hive
@XercesSociety @CornellEnto #Pollinators
Resource proximity is most important for solitary to semi-social species
@XercesSociety @CornellEnto #Pollinators
Bees size diversity.
Flight distance "largely" depends on bee size.
Smaller bees, small foraging range, ~25 METERS. (Within range of urban garden sizes)
Large bees can forage up to 5 miles.
@XercesSociety @CornellEnto #Pollinators
Bee diets: Specialist - generalist continuum.
Specialist typically refers to pollen specialization.
Nectar provides amino acids, so possible specialization there.
Example: Lasioglossum oenethera
@XercesSociety @CornellEnto #Pollinators
Phenology: When bee species are active.
Some are only active during narrow ranges of dates.
Osmia: Early, April-May
Digging Bees: Two seasons, April-June, Aug-Sep
Leaf-cutters: May-Sep
(I see some of thee persist even later in the fall)
@XercesSociety @CornellEnto #Pollinators
Nesting types: Soil nesting (70%), Cavity nesting (30%)
Different treatments of pollen, from loose (Osmia) to soup (Squash) to tight balls (Colletes)
Learning how bees manage the microbiome of nest provisioning
@XercesSociety @CornellEnto #Pollinators
Specialized collection for nesting materials, both pollen and construction.
Lifecycle: Solitary-semi-social, most spent underground, before they emerge
Some species overwinter - "diapause" - as pre-pupa, some as pupa
@XercesSociety @CornellEnto #Pollinators
11 months underground, 1 month flying.
Need to pay attention to soil: tilling, pesticides, etc.
(Read about Colletes on my blog.)
@XercesSociety @CornellEnto #Pollinators
Native bees tie to their landscape.
COULD move some cavity-nesting bees. Ground-nesting bees can't be moved.
Honeybees have trouble pollinating bilateral flowers (!!!), hanging flowers, e.g.: blueberries
@XercesSociety @CornellEnto #Pollinators
Threats: Development, Pesticides, Habitat, Pests, Pathogens, Competition, Climate change, Predators
Research: Apple orchards, range from complex landscape to "simple" (monoculture)
@XercesSociety @CornellEnto #Pollinators
Wild bees abundant and diverse in apple orchards overall, but ranging widely from 10-15% to nearly 100%
Correlated with proximity to natural habitat, e.g.: trees
Finding lots of bees in wind-pollinated trees (!!!)
@XercesSociety @CornellEnto #Pollinators
Wild bee abundance: correlates with apple seed set
Honey bee abundance - NO EFFECT ON SEED SET (My Emphasis)
@XercesSociety @CornellEnto #Pollinators
WHICH specie carry apple pollen?
Ordered list: Andrena, Osmia, Halictus, Bombus
Wild bees contact stigma 2-1/2 times more than honeybees
Melandrena deposit more 2x more pollen than honeybees
@XercesSociety @CornellEnto #Pollinators
Research: Strawberries
Planted wild flower strips on Complex to Simplified landscapes
Species visit apple and strawberry
More, larger, and better quality fruit produced near wildflower strips
Skin more resistance to plant bugs
@XercesSociety @CornellEnto #Pollinators
Exposure: Direct application, drift, puddles, soil
Systemic pesticides, e.g.: neonicotinioids, highly mobile, persistent in soil, expressed in pollen and nectar
@XercesSociety @CornellEnto #Pollinators
Impacts: lethal and sub-lethal
Sub-lethal: Foraging behavior, larval development, resistance to pests and pathogens, fungicides can affect microbiome of bee gut, reduced abundance and diversity in landscapes
@XercesSociety @CornellEnto #Pollinators
Larson, Redmond, and Potter, PLOS One 2013, Studied Bumblebees
Bees can't tell if pesticides have been applied.
@XercesSociety @CornellEnto #Pollinators
Bumblebee colonies perform WORST in suburban v. agricultural landscapes. (Lawns?!)
(Home gardeners apply pesticides at FAR higher rates than agricultural)
@XercesSociety @CornellEnto #Pollinators
Honeybee Research: 120 hives across 30 sites
Some orchards above EPA level for acute exposure (5 above European standards)
WHEN pesticides sprayed: during apple bloom, or not. But pollen from adjacent plants also found.
@XercesSociety @CornellEnto #Pollinators
Native Bee Research: Abundance and diversity decrease with increased pesticide use
Fungicides, NOT insecticides, HAVE GREATER IMPACT ON WILD BEE COMMUNITIES (My Emphasis)
@XercesSociety @CornellEnto #Pollinators
Fungicides applied WHILE plants are in bloom.
Fungicide effects: Sub-lethal - disrupt foraging, larval development, reduce ability to cope with pests and pathogens
@XercesSociety @CornellEnto #Pollinators
Study: Bumblebee range contractions
Hive losses highly correlated with general fungicide use, specifically - Chlorothalonil, which predicts Nosema
B. impatiens 4x more likely to become infected with Nosema when exposed.
@XercesSociety @CornellEnto #Pollinators
Some fungicides affect honeybee PREFERENCE for nectar, can adjust based on effects
Chlorothalonil, while used in ornamental and landscape, as well as vegetable and fruit production
Acts as a synergist, mixed with other pesticides.
@XercesSociety @CornellEnto #Pollinators
Synergism: Combination of agents is more toxic than either alone.
Common synergists: triazoles - DMI/EBI fungicides, Chlorothalonil, Neonics, Pyrethroides
Synergists found commonly in wax and collected pollen
@XercesSociety @CornellEnto #Pollinators
Centrella et al, 2018 (submitted)
Possible mitigation: Pesticides buffered by diversity of diet
@XercesSociety @CornellEnto #Pollinators
Take aways:
1) Fungicides are more toxic to bees than pesticides.
2) Even "safe" fungicides may have synergistic effects that make them ore far more toxic in combination.
For more info: Pollinator Network @ Cornell pollinator.cals.cornell.edu
@XercesSociety @CornellEnto #Pollinators
Good Bee Habitat:
Floral abundance (I have collector's syndrome: lost of species, not many massed together) - 3-6 square feet minimum
Safe nesting sites
Variety of species, especially woodlots, willow and maple
Research host needs
@XercesSociety @CornellEnto #Pollinators
* Jarrod Fowler jarrodfowler.com
* Empire State Native Pollinator Survey (I'm participating!), nynhp.org/pollinators

@XercesSociety @CornellEnto #Pollinators
(As someone who's socially-challenged, I get a lot from events like this where I can meet fellow travelers, and even reconnect with some old friends.)
(I was talking with another participant and we tarted talking about @iNaturalist. She had some problems with creating a Place for her community garden, and complaints about support.
I created a new Place for her, so she could connect her Project.)
(So, @iNaturalist and naturalistas, welcome to Lentol Garden in Greenpoint, Brooklyn!
Kelly Gill back for Part 3: Creating and Managing Habitat, Pollinator Habitat Restoration and Management
Concepts from large-scale - farm, meadow - can be scaled down to urban settings (and vice versa!)
@XercesSociety @USDA_NRCS #Pollinators
Need to manage across diverse landscapes, multi-functional, not just "wild" areas.
Need healthy, connected habitat.
Lawn is the largest irrigated crop in the U.S.
@XercesSociety @USDA_NRCS #Pollinators
Habitat: Shelter, Food (and Water), Protection
Opportunities everywhere.
Not covered in depth today: Other "beneficial" insects.
Example: Syrphid flies. Larvae are predators. (I have LOTS of these in my garden!)
@XercesSociety @USDA_NRCS #Pollinators
Before "creating" new habitat, need to assess existing conditions: What's already there? Can we manage existing habitat?
Desirable, deficiencies, short- and long-term planning and management.
Too often: Funding to create, not maintain.
@XercesSociety @USDA_NRCS #Pollinators
Phase 1: Site Selection and Assessment
Can we establish plants? Will they persist?
Operations and disturbance.
Weed pressure, existing cover.
Accessibility of marginal areas.
@XercesSociety @USDA_NRCS #Pollinators
Pollinator Habitat: Nesting Sites
"Can't just be a flower-weather friends." Support through lifecycle, when they can't be seen - in the nest, over the winter
Hard to create ground nesting sites, soil type and access
@XercesSociety @USDA_NRCS #Pollinators
Easier to protect existing nesting sites.
Keep snags, dead trees, logs.
Plants with soft piths, hollow stems.
Don't discard plant material, can bundle and set aside.
@XercesSociety @USDA_NRCS #Pollinators
Need lots of floral resources close to nesting sites, short adult lifespan out of the nest.
Bumblebees: Opportunistic nesters. Brush piles, leaf litter, tall grasses, loose mulch.
@XercesSociety @USDA_NRCS #Pollinators
Pollinator Habitat: Pollen and Nectar
Focus first on adding perennials to the landscape, long-lived, provide winter cover, minimize disturbance.
Succession of bloom.
(Urban gardens often have a wide range of habitat over short distances.)
@XercesSociety @USDA_NRCS #Pollinators
Make sure plants are available, affordable, pesticide-free. Seeds are most economical, where available.
Horticultural varieties bred for visual characters, generally less access, or useful, to pollinators.
@XercesSociety @USDA_NRCS #Pollinators
Designs for wildflower seed mixes. Tip scale for high abundance and diversity of forbs for pollinators, lower grasses in mix than natural.
Prefer local ecotypes.
Seed mixes depend on year-to-year crop performance. Check for substitutions.
@XercesSociety @USDA_NRCS #Pollinators
Pollinator Habitat: Plants for Nesting
Hollow and pithy stems.
@XercesSociety @USDA_NRCS #Pollinators
Starting from Seed: need to assess weed pressure.
High weed pressure: Hard to start from seed.
Low weed pressure: Start planting more competitive native plants, first.
@XercesSociety @USDA_NRCS #Pollinators
High Weed Pressure: Often high disturbance history. Plan for years of weed control. (Seed banks)
Moderate: Often marginal. Easier to manage.
Low pressure: typically, agricultural land taken out of production.
@XercesSociety @USDA_NRCS #Pollinators
Pollinator Habitat: Site Preparation
Need seed-soil contact.
Shallow cultivaiton, avoid bringing up weed seeds - repeatedly knock back weeds, herbicides, cover/smother
@XercesSociety @USDA_NRCS #Pollinators
Smother cropping, e.g.: buckwheat.
Following weed control, prepare fine seedbed to max seed-soil contact.
Dormant seeding: many species want stratification over winter.
@XercesSociety @USDA_NRCS #Pollinators
Broadcasting: Even distribution on dry, windless days. Tamp in after casting.
Some equipment suitable for larger areas, e.g.: grassland drills.
Need to know what to expect: not instant satisfaction, frequent mowing 1st year
@XercesSociety @USDA_NRCS #Pollinators
High mowing: 8", keeps weeds down, keeps them from setting seed, keeps light at ground level for continued germination
2nd year: selective weeding.
Sleeps, creeps, leaps. (Standard garden calendar!)
@XercesSociety @USDA_NRCS #Pollinators
Post-seeding management: Keep after weeds
Long-term: For meadows, mow to keep woody species down, mow 1/3 each year in rotation, leave 6" stubble
Can interseed with competitive species to restore diversity.
@XercesSociety @USDA_NRCS #Pollinators
Establishing Habitat: Transplanting.
Flowering shrubs and trees offer large floral resources.
Quicker to establish more, need protection.
Wildflower plugs also suitable for smaller areas (like home gardens!)
@XercesSociety @USDA_NRCS #Pollinators
Hedgerows: Diverse shrubs and plants, vertical habitat, forest edge habitat, buffer zones, e.g.: riparian plantings
A lot of species in decline are tried to shrubland, successional habitats
@XercesSociety @USDA_NRCS #Pollinators
Pollinator Habitat: Small spaces, gardens
Fewer, better species.
Clump/group species.
Native bunch grasses.
Locally-sourced, open-pollinated, seed-grown plants.
(See: flatbushgardener.blogspot.com/p/native-plant…)
@XercesSociety @USDA_NRCS #Pollinators
Garden style
(Can use native plants in formal ways. I happen to like the "wild" style.)
Public gardens, educational, paths, benches, inviting
Allow "messy" areas - snags, logs, litter
Reduce disturbance at critical times.
@XercesSociety @USDA_NRCS #Pollinators
Community gardens ("common" areas are great for pollinator habitat)
Roadsides, Rights-of-way
Sense of place (Genius loci)
Urban Infrastructure, Ecotone, Seasonal characteristics
@XercesSociety @USDA_NRCS #Pollinators
Golf Courses: converting out-of-play areas from turf to wildflower habitat, saves labor, fuel, herbicides, etc.
@XercesSociety @USDA_NRCS #Pollinators
Maria van Dyke back for Part 4: From the field
"For certain species, NYC is as good or better than a natural area" - John Asher
@XercesSociety @USDA_NRCS #Pollinators
Mary Gardiner in Cleveland, Ohio (depressed real estate market) converting vacant lots to pollinator habitat
@XercesSociety @USDA_NRCS #Pollinators
NY apple growers: Have enough native bee pollination to stop "renting" honeybees or bumblebees for pollination.
Example: Saving $3-6K annually over 80 acres.
Measured as #wild bees/minute/square meter to assess suitability.
@XercesSociety @CornellEnto #Pollinators
Up next: Yolanda Gonzalez, Sam Anderson, Urban Agriculture Specialist, Cornell
@XercesSociety @CornellEnto #Pollinators
Commercial: anyone growing for market or at similar scale, both for-profit and private, also nonprofit with some sales
Community gardens: over 700 across NYC
Educational projects
@XercesSociety @CornellEnto #Pollinators
Most NYC commercial ag is soil-based, outdoors, at ground or rooftop.
Some greenhouses, usually hydroponic, e.g.: speciality greens.
Majority is diverse vegetables outdoors.
@XercesSociety @CornellEnto #Pollinators
"Harvest NY" is an 8-person team, 2 in NYC (the speakers!)
Program Areas: Needs assessment, Tech assistance, Workshops and Small Group Learning, General support for urban ag
@XercesSociety @CornellEnto #Pollinators
Special Programs: Mushrooms, Food Safety, Lean Farming (process improvement, same Lean as in manufacturing, software delivery)
IPM (Integrated Pest Management), soil surveys, Insect (pest) scouting network starting this year with Brassicas
@XercesSociety @CornellEnto #Pollinators
Wow, and like that, it's over!
@XercesSociety #Pollinators
They'll be sending us PDFs of the presentation materials, with all the links and references. I synopsized so much, and have so many thoughts and questions, it may take me a few days to catch up.
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