An evening with some pollinators - University Of Maryland · Dr. Paula Shrewsbury...

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Dr. Paula [email protected]

Department of Entomology

University of Maryland, College Park, MD

How to Attract Predators and Parasitoids to Improve Biological Control

Biological Control Conference

December 17, 2019

Today’s topics

• Arthropod services in managed environments

• Threats / factors that disrupt arthropods and their services that lead to pest outbreaks

• Concepts underlying conservation of natural enemies

• Practices to conserve natural enemies

• On-line resources

Insects provide vital ecosystem services

• Critical links in food webs and food chains

• Nutrient recycling, decomposition

• Pollination

• Biological control

Predators

Lady Beetle

Flower or Hover Fly

Diptera: Syrphidae

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M.J. Raupp

M.J. Raupp

Video by M.J. Raupp, UMD; Bug of the Week YouTube

Assassin bugsHemiptera: Heteroptera

Reduviidae


Parasitoids

www.obsessedbynature.com

C. Brodo, UMD

• More common in managed environments than natural ones…

• Why?

• How do we prevent or reduce pest outbreaks and their associated impacts?

Pest Outbreaks

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Factors disrupt arthropods by:

• Reduce abundance and diversity of natural enemies (habitat, food resources, movement, synchronization with host) herbivores perform better (top down factors)

• Effect plants so they are more nutritious and / or less defended herbivores perform better (bottom up factors)

• Result in pest outbreaks

Urbanization Gradient

• An environmental gradient with less

developed natural areas at one extreme

and highly developed areas dominated

by anthropogenic structures and inputs

at the other extreme

http://psahomes.com http://www.globalsiteplans.com

Threats to the sustainability of managed landscapes

1.Lack of plant and animal biodiversity

2.Substitution of exotic plants for native plants

3.Importation of exotic, invasive species

4.Climate change – the warming of our cities

5.Impervious surfaces – heat islands, water infiltration, compaction, stress

6.Anthropogenic inputs of nutrients and pesticides

Habitat modification

Conservation Biological Control and Conserving Beneficials

The deliberate attempt to maintain beneficial organisms (natural enemies, pollinators) in the nursery or landscape habitat

1. Enhancement of the habitat to promote beneficial survival and reproduction, and to attract and retain beneficials

2. Avoidance of activities that are harmful to or disrupt beneficials

Many natural enemies are pollinators

Many pollinators are natural enemies

R. Waterworth, UMDM. J. Raupp, UMD

P.M. Shrewsbury, UMD

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Many natural enemies are omnivores and need alternative food sources such as nectar, pollen and seeds

Today’s topics

• Arthropod services and pest outbreaks in managed environments

• Threats / factors that disrupt arthropods and their services

• Concepts underlying conservation of natural enemies

• Practices to conserve natural enemies

• On-line resources

Plant Diversity can be estimated different ways

•Species richness - number of plant species

•Structural complexity – vegetation found in a three dimensional space

Landscape biodiversity is important!

ground cover or turfherbaceous plants

shrubs

understory

overstory

Structural complexity

Shrewsbury and Raupp 2000, Environmental Entomology

Structural complexity = 70

Structural complexity = 225

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Number of Plant Species

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mb

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of A

rth

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s Relationship Between the Number of

Plant and Arthropod Pest Species

P< 0.001, r2=0.18

Raupp et al. 2001

Increased plant species diversity

in a landscape results in more

potential alternate prey items to

support natural enemies.

Evidence shows that natural

enemies suppress pest

populations more often in the

presence of alternate prey

Why are there more predators and greater predator pressure in complex landscape habitats?

Additional food sources – alternate prey-Coriandrum sativum and Chrysanthemum maximum, increased alternate prey and

n.e. abundance and reduced survival of Stephanitis pyrioides – Shrewsbury, Lashomb,

Hamilton, Zhang, Patt, Casagrande

- Lobularia maritima, Coreopsis verticillata, and Panicum virgatum increased alternate

prey and n.e. abundance and reduced survival of Agrotis ipsilon - Frank and Shrewsbury

Simple Complex0

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Abundance in simple and complex landscapes

Complex landscapes have more alternate prey

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Number of Alternative Prey

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Do important predators respond to variation in prey abundance?

Shrewsbury and Raupp 2006, Ecological Applications

Structural complexity

Plant species richness

Refuges

Microclimates

Alternate food sources

(prey, nectar, pollen)

Is it possible to design or modify landscapes and nurseries with increased diversity to:- Reduce pests

- Increase natural enemies and pollinators

- Enhance ecosystem services

How could you do it?

Add flower and plant diversity

• What do we know already?

• What do we need to think about?

• How can you apply this information to increase biological control in systems where you work?

Add flowers

to landscapes

Shrewsbury et al. 2004, IJEES

RefugesMicroclimates

Alternate food sources(prey, nectar, pollen)

Shasta daisy and coriander around azaleas

Conclusions:

Azaleas with flowers

planted around them

had:

• Greater abundance of alternate prey

• Greater abundance of natural enemies

• Lower survival of azalea lace bug

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Conservation strips in Golf Courses

Tee

Green

Fairway Rough

Frank and Shrewsbury 2004, Enviromental Entomololgy

Nursery Ecosystems

P. Shrewsbury, UMD

P. Shrewsbury, UMD

• Nursery manipulations to increase structural complexity and plant species diversity, and favorable management practices

– Cover crops

– Grass alleys with flowers

– Hardwood mulch groundcover over weed cloth

– Pot-in-pot planting method

– Conservation strips / flowering plants

Benefits of cover crops

•Attract and retain natural enemies (biological control)•Floral resources, summer and winter habitat, alternate prey

•Reduce insect / mite pest damage

•Suppress plant parasitic nematodes

•Weed suppression

•Increase organic matter for soil improvement

•Root penetration to alleviate soil compaction

•Improve water movement

•Reduce soil erosion

•Addition of nitrogen (N) by N-fixing legume cover crops

•Alters nitrogen cycling by taking up N in the fall (likely reducing N leaching) and releases it in the spring when trees and shrubs need N

Nursery Cover Crop Project

Experimental design• Cover crops will be evaluated in 4 types of areas

common to most field nurseries 1) tree row bare zones 2) tree row fallow areas 3) grass alleyways4) open field areas

• Treatments– Cover crop species,combinations, and planting time

Tre

e

Row

Grass Alley

Grass Alley

Grass Alley

Bare Zone

Fallow Area

Tre

e

Ro

w

Tre

e

Row Fallow Area

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Bare Zone Tree Row Study

Forage radish, Raphanus sativus (Brassica)

Fall 2008


Crimson clover, Trifolium incarnatum (Legume)

Spring 2009


Alyssum, Lobularia maritima (Brassicaceae)

Summer 2009


Buckwheat, Fagopyrum esculentum (Polygonaceae)

Summer 2009

Nursery Cover Crop ProjectSunnhemp, Crotalaria juncea ‘Tropic Sun’ (Legume)

Fixes N, 5000 lb/acre dry weight, 100 lb

N/acre, adapted to infertile soils, grows well

with 8-16 weeks warm weather

Nursery Cover Crop ProjectOpen Field Areas: Percent of Ground with Cover

Crop, Weeds, and Soil

Nursery Oct. 2008

Forage Radi sh Sunn Hemp Conventi onal

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Forage Radi sh Sunn Hemp Conventi onal

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Cover Crop Weeds Soi l

Nursery Nov. 2008

Note: Sunn hemp was killed by frost

prior to Nov. sampling

Forage radish seeded: 8/31/08

Sunn hemp seeded: 9/4/08

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Efforts towards the conservation of natural

enemies and pollinators

Obj. To evaluate the impact of beds of

flowering plants (conservation strips) in

production nurseries on:

• Pollinator abundance and diversity

• Natural enemy abundance

and diversity

• Biological control services

R. Waterworth, UMD

Shrewsbury and Waterworth, current study, 2017-18

Raemelton Farm and Ruppert Nursery

Efforts towards the conservation of natural

enemies and pollinators

• Seed mix of annual and perennial

flowers, native and exotic

– 19 species

– Select percentage seed of each

species

• Based on research that

demonstrated attraction of

pollinators and/or natural enemies (ex. attract parasitoids that attack scale

insects)

• Commercially available seeds

• Something blooming throughout the

season


Colias sp on Symphyotrichum novae-

angliae

Results: # of Pollinator Species Collected by Plant

Common Name Plant Species #

Coreopsis Coreopsis lanceolata 20

Cornflower Centaurea cyanus 16

Butterfly milkweed Asclepias tuberosa 11

Grey-headed coneflower Ratibida pinnata 10

Cup plant Silphium perfoliatum 14

Spotted beebalm Monarda punctata 11

Sulfur cosmos Cosmos sulphureus 17

Rigid goldenrod Solidago rigida 4

New England aster Symphyotrichum novae-angliae 13

Smooth Aster Symphyotrichum laevis 18


Size and arrangement of landscape beds

• How big do the conservation beds have to be?

• How close do the conservation beds have to be?

– Habitat patches that are bigger and closer to other patches tend to be better than smaller, isolated patches

– However, every plant counts

– Clumps of plants of the same species, within patches tend to be better than single plants

Plant Origin – Native or Exotic

• Function of the plant

– Will it survive / thrive in the habitat?

– Quality and availability of the pollen and nectar

– What does it attract and support?

• Avoid invasive or aggressive species

Plant Selection: Bloom period

From: Xerces Society – Pollinator-Friendly Plants – Mid-Atlantic Region at: http://www.xerces.org/pollinator-conservation/plant-lists/

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Sweet Alyssum

Coreopsis

Switchgrass

Plant Selection: Floral and Plant Architecture

Gaillardia

Liatris Yarrow

Plant Selection: type and species

• Plant / flower species– Research-based information

• Trees, shrubs, vines, wildflowers, herbs, perennials, annuals– Annuals tend to not be good sources of nectar and pollen, but there are exceptions (see: Protecting and enhancing pollinators in urban landscapes…)

• Diversify!

“Protecting and enhancing pollinators in urban landscapes for the US North Central Region”

-Provides information for landscapers and gardeners who want to attract pollinators and protect them when implementing pest management tactics-Plant lists-Timing of pesticide trts

http://msue.anr.msu.edu/resources/how_to_protect_and_increase_pollinators_in_your_landscape

Frank, Shrewsbury, & Esiekpe, 2008 Environmental Entomology (37:2)

MD Native plant species tested to determine

their attractiveness to natural enemies

Common name Scientific name Family

Common milkweed Asclepias syriaca Asclepiadaceae

Butterfly weed Asclepias turberosa Asclepiadaceae

Threadleaf coreopsis Coreopsis verticillata Asteraceae *

Hyssopleaf thoroughwort Eupatorium hyssopifolium Asteraceae *

Spotted horsemint Monarda punctata Lamiaceae *

Narrowleaf mountain mint Pycnanthemum tenuifolium Lamiaceae *

Skullcap Scutelaria integrifolia Lamiaceae

Switchgrass Panicum virgatum Poaceae

Indiangrass Sorghastrum nutans Poaceae

Little bluestem Schizachyrium scoparium Poaceae


www.croatianworld.net

Coreopsis verticillata

Eupatorium hyssopifolium

www.ct-botanical-society.org

Monarda punctata

groups.ncf.edu

Pycnanthemum tenuifolium

www.ct-botanical-society.org

“Winners” -

MD Native

Insectary

Plants


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Eupatorium perfoliatum L.

Monarda punctata L.

Silphium perfoliatum L.

Potentilla fruticosa auct. non L.

Coreopsis lanceolata L.

Spiraea alba Duroi

Agastache nepetoides (L.)

Kuntze

Anemone canadensis L.

Angelica atropurpurea L.

MI Native Beneficial

Insectary Plants

Cup plant

Silphium

perfoliatum L.

http://nativeplants.msu.edu

Canada anemone

Anemonecanadensis L.

Shrubby cinquefoil

Potentilla fruticosa auct. non L.

Meadowsweet

Spiraea alba Du Roi

Yellow giant hyssop

Agastache nepetoides (L.) Kuntze

Angelica

Angelica atropurpurea L.

MI Native Beneficial

Insectary Plants

http://nativeplants.msu.edu/pdf/E2973.pdf

-Native plants

-Pollinators and natural enemies

-Table of plants, bloom times, and rating of attractiveness to natural enemies and pollinators

From: MSU – Attracting Beneficial Insects with Native Flowering Plants at: http://nativeplants.msu.edu/pdf/E2973.pdf

Plant Selection: Plants to conserve beneficials

Impervious Surfaces

Disrupt movement and

colonization of herbivores

and/or natural enemies

Creation of heat islands

Host quality and accessibility

•Vary dramatically across urban gradients, fragment habitats, affect

plant density, alter thermal regimes and plant-water relations, and

inhibit movement of herbivores and their natural enemies

Reduced connectivity of green space

Urban green space

-types: residential gardens, parks, motorways, traffic

circles, green roofs / walls, community gardens

-design: connectivity and spacing, number / amount of

green space, plant selection

-benefits: sustain biodiversity (plants, arthropods,

wildlife) and ecosystem services, movement, reduce

arthropod outbreaks, reduce heat island effects, rain

water impacts (erosion, runoff), carbon sequestration,

improved mental health / quality of life

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http://nativeplants.msu.edu/pdf/E2973.pdf

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Habitat Manipulation -Recommendations:• Increase structural complexity

– More plants at different vegetational strata– More green space

• Increase plant biodiversity– More plant species, families– Include trees, shrubs, vines, perennial flowers and herbs

• Add flowers– vary architectural complexity– provide overlapping and season long bloom

• Select plants based on proven attractiveness and the natural enemies and pollinators they attract

• Provide nesting and egg laying sites

• To provide:– a community of plant species that attracts diverse natural

enemy and pollinator taxa and provide habitat, nectar and pollen throughout the season

Do insecticide reduce abundance and disrupt activities of natural enemies resulting in loss of top-down regulation?

Secondary pest outbreaks associated with insecticide applications in urban areas

Target pest: Outbreaking pests:

Japanese beetle citrus red mite, woolly whitefly, purple scale

Mosquitoes pine needle scale

Filth flies European fruit lecanium

Hemlock woolly adelgid spruce spider mite, hemlock rust mite

Asian longhorned beetle Scheonei spider mite

Unknown (cover sprays) euonymus scale, white prunicolascale, pine needle scale

Impacts of a neonicotinoid, neonicotinoid–pyrethroid premix, and anthranilic diamide

insecticide on four species of turf inhabiting beneficial insectsJ.L. Larson, C.T. Redmond, D.A. Potter, 2014, Ecotoxicology

Compared the impact of:

– a neonicotinoid (clothianidin [Arena])

– a premix (clothianidin [Arena] / bifenthrin [Talstar])

– an anthranilic diamide (chlorantraniliprole [Acelepryn])

Four species of beneficial insects:

• Harpalus pennsylvanicus, an omnivorous ground beetle

• Tiphia vernalis, an ectoparasitoid of scarab grubs

• Copidosoma bakeri, a polyembryonic endoparasitoid of black

cutworms

• Bombus impatiens, a native bumble bee



Results:Clothianidin (Arena) or the premix (clothianidin / bifenthrin

(Talstar))

• Ground beetles suffered high mortality

• Reduced parasitism by Tiphia vernalis

• Copidosoma bakeri wasps suffered high mortality

• Reduced numbers of workers in bumble bee colonies

Chlorantraniliprole (Acelepryn)

• No apparent adverse effects on any of the beneficial species



Recommendations:• Adjust application timing and avoid seasonal activity of adult parasitoids

• Do not apply to blooming, pollen-shedding, or nectar-producing parts of

plants that may be visited by bees

• Control spring-flowering weeds:

o mow to remove flower heads before or immediately after the

application OR

o wait until after weeds have finished blooming

• Use granular formulations, as opposed to sprays, to reduce exposure of

residues to bees and above-ground parasitoids

• Use target-selective insecticides. Compared to neonicotinoids,

chlorantraniliprole (Acelepryn) has no adverse effect on beneficials, and:

o similar strong efficacy against scarab and billbug larvae

o better activity against caterpillars

o less active against sucking pests

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EPA Reduced Risk Pesticides

• Acequinocyl – miticide

• Bifenazate – miticide

• Pymetrozine – aphids, whiteflies

• Spinosad – caterpillars, sawflies, leafmining flies

• Tebufenozide – caterpillars

• Acetamiprid – many sucking insects

• Chlorantraniliprole – caterpillars, grubs, lace bugs, clearwing borers

• Cyantraniliprole – aphids, lace bugs, Jap. beetles, leaf beetles, caterpillars, leafminers, soft scale, thrips, whitefly

Organic Materials Review Institute (OMRI)

• OMRI - a nonprofit organization founded in 1997.

• Provides organic growers, manufacturers, and suppliers

an independent review of products intended for use in

certified organic production, handling, and processing.

• Acceptable products are OMRI Listed® and appear on

the OMRI Products List© or OMRI Canada Products

List©.

• OMRI lists 184 insecticides for a wide variety of pests

including those in landscapes

“Protecting and enhancing pollinators in urban landscapes for the US North Central Region”

-Provides information for landscapers and gardeners who want to attract pollinators and protect them when implementing pest management tactics-Plant lists-Timing of pesticide trts

http://msue.anr.msu.edu/resources/how_to_protect_and_increase_pollinators_in_your_landscape

• Choose pesticides wisely!

– Low toxicity, selective, short residual activity, IGR

– EPA Reduced Risk or OMRI listed pesticides

– Read and follow label directions carefully!

• Integrate alternative control measures (IPM)

– Cultural, mechanical, or biological tactics

Recommendations

Threats to the sustainability of managed landscapes

1.Lack of plant and animal biodiversity

2.Substitution of exotic plants for native plants

3.Importation of exotic, invasive species

4.Climate change – the warming of our cities

5.Impervious surfaces – heat islands, water infiltration, compaction, stress

6.Anthropogenic inputs of nutrients and pesticides

Why we want to attract and retain natural enemies in managed environments…


Wheel bug stalking a caterpillar

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2020 ADVANCED LANDSCAPE IPM PHC SHORT COURSE

January 6 - 9, 2020University of Maryland Entomology Department & Maryland Extension Service

Description

• The annual Advanced Landscape IPM PHC Short Course is a recertification short course for arborists, landscape supervisors, IPM monitors, advanced gardeners, and others responsible for urban plant management.

Location

• Entomology Department in Room 1140 Plant Sciences Building on the University of Maryland campus in College Park, MD.

Dates

• Monday, January 6 - Thursday, January 9, 2020

Time

• Lecture: 8:00am - 3:00pm

• Lab (optional): 3:30 - 5:30pm (Note: Lab is full)

https://landscapeipmphc.weebly.com/

Contact for information:

Amy Yaich, Admin. Assist. II

Department of Entomology

University of Maryland

Phone: 301-405-3911

E-mail: [email protected]

THANK YOU!

Paula Shrewsbury, Ph.D.

University of Maryland

[email protected]

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https://landscapeipmphc.weebly.com/

mailto:[email protected]

An evening with some pollinators - University Of Maryland · Dr. Paula Shrewsbury...

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