Doing it Biologically !!!
Opportunities to use Natural
Enemies on Landscape Ornamentals
Michael Brownbridge
Entomology Research Laboratory
University of Vermont
Biocontrol success in greenhouses…
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controlled environment
closed environment
once released, natural enemies remain
on the crop
Why are there fewer options for
landscape ornamentals ?
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environmental conditions more
variable, may be sub-optimal
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pests can migrate in from surrounding
environment
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natural enemies will head for the food
source – may not be on your plants!
Few beneficials with proven efficacy
Sanitation
Cultural
IPM
Chemical
Biological
Pest management is a
dynamic process:
• Pest outbreaks vary from year to year
• Influenced by location, weather
• Plant variety
• Market
• Clientele
Why biologicals? Why IPM?
1. Pesticide stewardship important:
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to delay resistance
limited number of new insecticide
registrations; FQPA = net loss
2. Health and safety of staff, general public
3. Environmental concerns
4. Difficult to work nr. schools, residential
areas
Scouting – knowing what’s going on
on your plants!
• Early detection
• More control options
• Better control
• More cost-effective
Bacillus thuringiensis - Bt
• Bt kurstaki e.g. Dipel
• Bt aizawai e.g. Xentari
• Bt san diego, tenebrionis
caterpillars
caterpillars
beetles
elm leaf beetle, imported willow leaf beetle;
not viburnum leaf beetle
Viburnum leaf beetle eggs
Prune infested twigs Oct-mid
April
Optimizing Bt efficacy:
• Select correct strain
• Good spray coverage
• Apply early vs. young larvae
• More susceptible
Less damage, less product, more
cost-effective
Insect-parasitic
nematodes
Nematodes for
slug control
Produced by:
BeckerUnderwood
Sold through:
AgBio Inc.
HETEROMASK™
Heterorhabditis bacteriophora
Steinernema carpocapsae
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Effective at 70 – 85° F
Dogwood borer, banded ash clearwing borer, lilac
borer, oak borer, peach tree borer (larvae)
Steinernema kushidai
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Japanese beetle, oriental beetle (larvae)
Difficult to mass produce
Steinernema feltiae
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Fungus gnat larvae in propagation houses
Will work at temps down to 50 ° F
Atheta coriaria
rove beetle
Predator of shore fly
and fungus gnat larvae,
pupating thrips.
Excellent control of shore flies obtained when
released at 100 beetles per week per 5000 sq. ft
of greenhouse; releases made in early morning or
late evening.
Nematode use practices:
• Active vs. larvae; most effective in containers/pots
• Apply to moist soils by drenching
• Apply when host larvae present
• Soil temperature is important
• Compatible with many fungicides and insecticides
• www.agnr.umd.edu/users/ipmnet/nemanurs.htm
Beauveria bassiana
Metarhizium anisopliae
‘Rhizosphere-competent’
Ladybeetles
• Active release?
• Naturally-occurring
Green lacewing larvae
Chrysoperla carnea
lacewing eggs
feeding on azalea
lace bug nymphs
Spider mites
• Rapid reproductive rate
• Short generation time
• Damaging populations build quickly
• Pesticide resistance
• Broad-spectrum pesticides, resurgence
Spider Mite Predators
Phytoseiulus persimilis
• good vs. two-spot in greenhouses
• does not work well outdoors in cooler regions
Neoseiulus fallacis
• wider host range
• works outdoors (strawberries, apples)
• may overwinter outdoors
• use early in infestation cycle
• release onto infested plants
• www.ent.orst.edu/prattp/plant.html
Biocontrol of euonymus scale
• Cybocephalus nipponicus
• Originally from Korea
• Released in NJ on infested euonymus
• Established in infestation sites
Conservation Biological Control
• Conserve naturally-occurring beneficials
• Create an environment that is attractive to beneficials
• Avoid use of broad-spectrum insecticides
Enormous benefits, minimal cost
Habitat manipulation to increase biodiversity
Flowers attract predators
and parasitoids; other insects
serve as alternate prey/hosts
Use of alternative ground covers
University of Maryland, Paula Shrewsbury www.shrewsburylab.umd.edu
• wood mulch on/in place of fabric mat
• provides a more favorable habitat for generalist predators
• refugia, alterative prey
ground beetle larva
predatory mites
In avocado orchards, mulching increased the
incidence and activity of natural enemies and
other beneficial arthropods.
Using pesticides
• Create habitats to maintain natural enemies (refugia)
Flowering plants, ivies, vines
• Select and use ‘soft’ or ‘reduced-risk’ pesticides
Short residual activity, narrow host spectrum, IPM
compatible. EPA classification, limited use
restrictions
Bio-derived Products
Minimum-risk pesticides, exempted from registration
requirements – even in NY!!!
• E-Rase – Jojoba oil; whitefly control
• GC-Mite – cotton seed and clove oils, garlic extract; mites, thrips
• Hexycide – rosemary and mineral oil; whiteflies?
• Organocide – sesame oil; aphids, mites, powdery mildew
Very little efficacy data available on any of
the products. May be phytotoxic – test on a
limited number of plants before treating a
whole crop!
Spray Oils and Insecticidal Soaps
• Ultra-Fine Spray Oil (Whitmire)
• Dormant oils
• Synergy Super Fine spray oil emulsion (Griffin)
- micro-emulsion process = remains in suspension for 3 h
• PureSpray Foliar 15 (Purespray Green?); Petro Canada
- used in Canada on tree crops, fruits, ornamentals
- pursuing registration in the US
• Olympic Insecticidal Soap, M-Pede
Broad-spectrum, but short residual; often applied at
times of year when little natural enemy activity.
Beware of phytotoxicity, esp. on spruces and conifers,
after bud-break or in early dormancy.
Neonicotinoid Insecticides
Similarities:
• Expensive
• Long residual control
• Excellent plant safety, low mammalian toxicity
• Systemic or translaminar movement
• Active vs. piercing/sucking insects
• Variable activity against other pests
• Similar modes of action, risk of cross-resistance
Neonicotinoid Insecticides
Pioneer products: Marathon, Discus, Xenith, Merit
New products:
 TriStar (Cleary’s) – Acetamiprid
spray application only
 Safari (Valent) – Dinotefuran
very water-soluble, readily translocated
 Clutch/Arena (Arvesta) – Clothianidin
 Flagship (Syngenta) – Thiamethoxam
Various formulations for spray or drench application
Other reduced-risk insecticides
• Flagship, Endeavor
very effective vs. aphids (sprays), mealy bugs (drench)
• Conserve
caterpillars, leaf-feeding beetles, short residual
Reduced-risk miticides
• TetraSan
translaminar activity vs. spider mites, ovicidal, slow-acting
• Floramite
good for early-season infestations, compatible w. predators, selective
• Hexygon
restricted use label in NY
• Ornamite
Limited n. applications per growing season; resistance
management
Products to avoid:
• organophosphates Dursban, Diazinon, Dimethoate
• carbamates Sevin, Furadan
• pyrethroids Talstar, Tame, Ambush (Pounce)
Broad-spectrum, long residual, highly toxic.
Many withdrawn for nursery and residential use;
restricted use.
Pest resurgence, secondary pest outbreaks.
www.ent.orst.edu/prattp/pesticides.html for compatibility with N. fallacis
Can you do it biologically?
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Take active steps to release and preserve natural
enemies
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Create an environment that conserves and
encourages activity
Use reduced-risk pesticides only when necessary in
a planned IPM strategy
Will depend on plant species, pest and infestation
level, time of year, location and clientele
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Thanks to:
New England Grows
Paula Shrewsbury, Univ. Maryland
Carol Glenister, IPM Labs, Locke, NY
Dan Gilrein, Cornell Univ. Cooperative Extension
This presentation is available for download on our website:
www.uvm.edu/~entlab
Click on ‘Recent Publications’