Doing it Biologically !!!

Opportunities to use Natural Enemies on Landscape

OrnamentalsMichael Brownbridge

Entomology Research Laboratory

University of Vermont

Biocontrol success in greenhouses…

• controlled environment

• closed environment

• once released, natural enemies remain on the crop

Why are there fewer options for landscape ornamentals ?

• environmental conditions more variable, may be sub-optimal

• pests can migrate in from surrounding environment

• natural enemies will head for the food source – may not be on your plants!Few beneficials with proven efficacy

IPM

Sanitation

CulturalBiological

Chemical

Pest management is a

dynamic process:

• Pest outbreaks vary from year to year

• Influenced by location, weather

• Plant variety

• Market

• Clientele

1. Pesticide stewardship important:

• 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

Why biologicals? Why IPM?

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

caterpillars

• Bt aizawai e.g. Xentari caterpillars

• Bt san diego, tenebrionis beetleselm 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

Produced by:

Becker-Underwood

Sold through:

AgBio Inc.

Nematodes for slug control

HETEROMASK™

Heterorhabditis bacteriophora

Steinernema carpocapsae

• Effective at 70 – 85° F

• Dogwood borer, banded ash clearwing borer, lilac borer, oak borer, peach tree borer (larvae)

Steinernema kushidai

• Japanese beetle, oriental beetle (larvae)

• Difficult to mass produceSteinernema feltiae

• 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

feeding on azalea lace bug

nymphs

Green lacewing larvae

Chrysoperla carnea

lacewing eggs

Spider mites

• Rapid reproductive rate

• Short generation time

• Damaging populations build quickly

• Pesticide resistance

• Broad-spectrum pesticides, resurgence

Phytoseiulus persimilis

• good vs. two-spot in greenhouses

• does not work well outdoors in cooler regions

Spider Mite Predators

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 coversUniversity 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 InsecticidesSimilarities:

• 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) – Dinotefuranvery water-soluble, readily translocated

Clutch/Arena (Arvesta) – Clothianidin Flagship (Syngenta) – Thiamethoxam

Various formulations for spray or drench application

Other reduced-risk insecticides

• Flagship, Endeavorvery effective vs. aphids (sprays), mealy bugs (drench)

• Conservecaterpillars, leaf-feeding beetles, short residual

Reduced-risk miticides

• TetraSantranslaminar activity vs. spider mites, ovicidal, slow-acting

• Floramitegood for early-season infestations, compatible w. predators, selective

• Hexygonrestricted 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?• Take active steps to release and preserve natural enemies

• 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

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’