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© Project SOUND Out of the Wilds and Into Your Garden Gardening with Western L.A. County Native Plants Project SOUND - 2009

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This lecture was given in March, 2009 as part of the California native plant gardening series ‘Out of the Wilds and Into Your Garden’

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Page 1: Pests   2009

© Project SOUND

Out of the Wilds and Into Your Garden

Gardening with Western L.A. County Native Plants Project SOUND - 2009

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Pests, Pests, Pests

C.M. Vadheim and T. Drake

CSUDH & Madrona Marsh Preserve

Madrona Marsh Preserve

March 7 & 10, 2009

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What is a pest? An organism which has characteristics that are regarded by humans as injurious or unwanted

Eats a desired plant Causes disease in a desired

plant Carries disease to a desired

plant

May be:

A vertebrate (deer; rabbit) An insect/mollusk (snail) A bacterium, virus or fungus

A pest in one setting may be beneficial in another; like a weed, a pest may be an organism ‘in the wrong place’

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Predator/prey relationships in nature

http://www.champaignschools.org/science/images/foodweb.gif

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In nature, plants fight back…

Native plants evolved with insects, other animals, microorganisms – ecosystems in balance

Some produce noxious chemicals or physical barriers to ‘ward off’ natural pests

Some attract ‘helper species’ – insects & even birds

Some simply tolerate normal levels of predation

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A recipe for disaster

http://jenmill.blogspot.com/2006_04_01_archive.html

http://farm2.static.flickr.com/1118/814174806_a1348ae709.jpg

Plant species not native to area; often ‘cultivars’

Planted in mono-culture

Heavily watered & fertilized – ‘plants on steroids’

Using overhead watering during warm summer days

Globalization of pests

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The ‘Old California Garden’ requires an

arsenal of ammunition…

Issues:

Improper use

Overuse

Storage

http://www.improvementscatalog.com/home/improvements

/792923315-spray-doc-wheel-garden-sprayers.html

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And the consequences are not pretty…

Human/animal health risks

Contaminated soils & water (including street water runoff)

High cost of pesticides

Beneficial species killed

Effects on animals up the food chain

Pesticide resistance

http://grapes.msu.edu/images/pesticResist.gif

http://www.mindfully.org/Pesticide/2002/Flawed-Frogs-Pesticide-Deformed9jul02.htm

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The ‘New California Garden’ is based on a better strategy

Plant the plants that are ‘programmed’ to be successful in your area – these will:

Be less stressed – and therefore healthier Be prepared to ‘fight’ the natural enemies Attract natural ‘helpers’ in their fight against pests

Plant a variety of species – more like a natural ecosystem (not a monoculture)

Give the plants the appropriate gardening care:

Appropriate levels of water Appropriate (often little to no) fertilizer Protection from other stress & injury

Have an appropriate strategy to deal with true pests

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Many of us have found that just including more native species improves the ‘pest problems’ in the

entire garden

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But you need to have a sound strategy to dealing with certain pests…even on

native plants

And that’s where the concept of Integrated Pest Management (IPM) provides useful guidelines

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Integrated Pest Management (IPM)

"Optimum combination of control methods including biological, cultural, mechanical, physical and/or chemical controls to reduce pest populations to an economical acceptable level with as few harmful effects as possible on the environment and nontarget organisms."

R.L. Hix,CA Agric. Magazine, 55:4 (2001)

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What is Integrated Pest Management?

IPM programs use current, comprehensive information on the life cycles of pests and their interaction with the environment.

This information, in combination with available pest control methods, is used to manage pest damage by the most economical means, and with the least possible hazard to people, property, and the environment.’

http://www.epa.gov/opp00001/factsheets/ipm.htm

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The IPM Pyramid – ‘first do no harm’

Use the least invasive – and often most effective - means first: Prevention – cultural practices Mechanical Controls Naturally occurring biological

controls (native predators)

Consider using non-native predators

Use chemical controls sparingly, as a last resort: Naturally occurring elements Biologics – chemicals made by

plants that are toxic to pests/diseases

Non-biologic pesticides: Insecticides Fungicides Miticides

http://www.team.ars.usda.gov/ipm.html

Non-native predators and chemical

controls have the important drawback of

non-specificity – they kill the good pests

with the bad.

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Some of the benefits of an integrated

approach are as follows:

Promotes natural controls; ‘ecosystem approach’.

Protects human health.

Minimizes negative impacts to non-target organisms.

Enhances the general environment.

Is most likely to produce long-term, beneficial results.

Often is easily and efficiently implemented.

Cost-effective in the short and long-term.

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An IPM system is designed around six basic components

1. Set Action Thresholds Before taking any pest control action, IPM first sets an action

threshold, a point at which pest populations or environmental conditions indicate that pest control action must be taken. Sighting a single pest does not always mean control is needed. The level at which pests will either become an economic threat is critical to guide future pest control decisions.

2. Monitor and Identify Pests Not all insects, weeds, and other living organisms require control.

Many organisms are innocuous, and some are even beneficial. IPM programs work to monitor for pests and identify them accurately, so that appropriate control decisions can be made in conjunction with action thresholds. This monitoring and identification removes the possibility that pesticides will be used when they are not really needed or that the wrong kind of pesticide will be used.

3. Preventive Cultural Practices As a first line of pest control, IPM programs work to manage the

crop, lawn, or indoor space to prevent pests from becoming a threat. These control methods can be very effective and cost-efficient and present little to no risk to people or the environment.

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An IPM system is designed around six

basic components

4. Mechanical controls: Should a pest reach an unacceptable level, mechanical methods are the first options to consider. They include simple hand-picking, erecting insect barriers, using traps, vacuuming, and tillage to disrupt breeding.

5. Biological controls: Natural biological processes and materials can provide control, with minimal environmental impact, and often at low cost. The main focus here is on promoting beneficial insects that eat target pests. Biological insecticides, derived from naturally occurring microorganisms (e.g.: Bt, entomopathogenic fungi and entomopathogenic nematodes), also fit in this category.

6. Chemical controls: Synthetic pesticides are generally only used

as required and often only at specific times in a pests life cycle. Many of the newer pesticide groups are derived from plants or naturally occurring substances (e.g.: nicotine, pyrethrum and insect juvenile hormone analogues), and further 'biology-based' or 'ecological' techniques are under evaluation.

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IPM plan for your garden – a work in

progress

Requires observation & knowledge – specific for your garden

Will vary somewhat with: Yearly weather conditions Maturity of plants New plants

Will be modified based on your previous experiences

Suggestion: keep a garden notebook/journal

http://www.hoodcountymastergardeners.org/Demo_2006/Demo_Construction.html

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Many resources to help you

Books – check out your local library, or add to your own

On-line resources

County Master Gardeners

Other Governmental resources: (see list) U.S.

State & Local

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University of California

Statewide IPM Project (UCIPM)

Goals of the IPM Project are to: reduce the pesticide load in the

environment, increase the predictability and

thereby the effectiveness of pest control techniques,

develop pest control programs that are economically, environmentally and socially acceptable,

marshal agencies and disciplines into integrated pest management program, and

increase the utilization of natural pest controls.

Educational component: Print & on-line resources UC IPM Pesticide Education Program

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Set Acceptable Pest Levels

Find out what pests/ diseases occur in your garden – observation

Learn more about the pests, their effects What are their life-stages What seasons/conditions are

they associated with What plant species are

susceptible

Learn how to determine when action should be taken

http://www.ctahr.hawaii.edu/noni/spiralling%20whitefly.asp

http://waterroots.com/imagespests/whitefly03.jpg

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Monitor & Identify Pests

Base monitoring on garden conditions: temperature & humidity

Look for pests on vulnerable tissues

Shake out the pests, then view with magnifying glass

Decide if action is needed Suggestion: keep a log of dates,

conditions in your garden journal

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Prevention/Cultural Practices are the first

line of defense against pests

Cultural practices: just good old garden management practices

Providing alternate hosts for pests No monoculture Preventing over-wintering Sanitation Proper water & nutrient management Correct watering Physical barriers Pruning to improve air circulation Weeding Mulching

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Criteria for selecting a treatment

strategy are:

1. Least hazardous to human health

2. Least disruptive of natural controls

3. Least toxic to non-target organisms

4. Most likely to be permanent

5. Easiest to carry out safely and effectively

6. Most cost-effective

7. Most site-appropriate

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Pest challenges vary with the season….

Warmer weather & new growth – spring/early summer Sucking insects Chewing insects Gall & Blister Mites

Warm weather – summer/fall Foliage fungal diseases Borers (insects) Root/stem rots

(fungal/bacterial)

Cool, wet weather – winter/early spring Mollusks Anthracnose (fungal)

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Sticky (Bush) Monkey Flower -Mimulus/Diplacus aurantiacus

http://www.baynatives.com/plants/Mimulus-aurantiacus/

Scarlet Monkeyflower Musk Monkeyflower

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Sucking insects

Definition: Insects that insert their mouthparts into the sugary phloem (conducting tissue) & suck the ‘sap’

Examples: Aphids Mealy Bugs Whiteflies Psyllids Scales Leafhoppers

Damage: Often confined to the young, succulent

growth (leaves, shoot-tips and buds Tissues appear puckered or crinkled

Monitoring: watch for: Signs of the insects themselves –check

particularly undersides of leaves, other protected areas

Ants – tend to be ‘nurse’ species Abnormal plant growth

http://scienceblogs.com/neurophilosophy/Ant_cultivating_aphids.jpg

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Any perennial or shrub/tree with fresh

new foliage can attract sucking insects

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Aphids: where there’s one there are many…..

Often called plant lice, are small, soft-bodied insects.

They range in color from black to green to yellow.

Their numbers may greatly increase in a short time and crowding stimulates the production of winged forms.

They may cover the entire surface of a leaf or stem.

They (and other sucking pests) can be vectors of plant viruses (crop & ornamental plants).

They can also weaken plants, making them susceptible to other diseases

http://notexactlyrocketscience.files.wordpress.com/2006/08/aphid-sap.jpg

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Aphids – Ugly but not usually murderers...

Preventive cultural practices: Control ants Control weeds –

particularly Brassica species

Mechanical Controls: Blast off with a stream of

water Use sticky strips around

trunks to manage ants

Biological Controls: Lady bugs; Lacewings

Chemical controls: Insecticidal Soap is usually

adequate

http://ipm.ncsu.edu/cotton/insectcorner/photos/aphid.htm

http://pmo.umext.maine.

edu/factsht/Suck.htm

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Whiteflies

Monitoring: By placing yellow sticky cards in greenhouse &

other vulnerable environments Periodic inspection of undersides of leaves of

susceptible species Preventive cultural practices:

Don’t purchase infested plants Control ants Encourage natural predators

Mechanical Controls: Yellow sticky traps (early in infestation) Blast off with stream of water Hand-remove infested leaves Vacuum them up with hand vacuum

Biological Controls: Ladybugs, Lacewings, parasitic wasps & mites Songbirds

Chemical controls: Insecticidal Soap Chemical pesticides usually not very helpful –

resistance quickly develops

http://ipm.ncsu.edu/cotton/InsectCorner/photos/other.htm

http://agriculture.gov.bb/media/plant_protection/Whiteflies2.JPG

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Monitor particularly on citrus and vegetable crops (and plants near them)

Mechanical methods and encouraging natural enemies offer best chance for control

http://cekern.ucdavis.edu/Entomology/Woolly_Whitefly_Monitoring_in_Kern_Cou

nty.htm

Wooly Whitefly on Citrus

Ash Whitefly (Siphoninus phillyreae)

can attack Toyon & other natives

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Mealybugs Females feed on plant sap, normally in roots or

other crevices. They secrete a powdery wax layer (therefore the name mealybug) used for protection while they suck the plant juices.

Monitoring: Check stem axils & bottoms of plant stems for

insects Act immediately when you see them to control

infestation

Preventive cultural practices: Insect new plants – remove pests Control ants (which protect Mealybugs) Encourage natural predators

Mechanical Controls: Remove by hand & destroy Apply rubbing alcohol with a Q-tip or cotton

ball; destroys insects & egg masses [note: try on small area first – may damage plant]

Biological Controls: Lady Bug, Lacewings, parasitic wasps –all natural

Chemical controls: Insecticidal Soap or horticultural oils

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Controlling aphids, whiteflies & Mealybugs is an

important ‘cultural practice’ for preventing other diseases

Mealybugs are similar to whiteflies and aphids: they produce large amounts of waste product (honeydew) which coats plants and surrounding surfaces.

This sticky layer is a perfect growth medium for a black fungus commonly known as "sooty mold".

This mold damages plants by covering leaves and reducing light available for photosynthesis.

Sooty Mold

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True Bugs

Many are actually beneficial predators

Preventive cultural practices: Encourage healthy plants

Chemical controls: not recommended in most cases

http://pmo.umext.maine.edu/factsht/Suck.htm

Milkweed Bug

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Good natural enemies are there – just

plant species that will attract them

Green Lacewing

Common generalist predator

Kills: mealybugs, psyllids, thrips, mites, whiteflies, aphids, small caterpillars, leafhoppers, and insect eggs

Use common pesticides & you’ll kill this beneficial insect

Plant species in the Rose & Buckthorn (Ceanothus) families to provide food for Lacewings

Green Lacewing

You will need to learn about

the common beneficial

insects in order to recognize

and attract them

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Attract these

beneficial insects

By planting these species

Bigeyed bug Native grasses Polygonum sp. (Silver Lace Vine)

Hoverflies Achillea sp. (Yarrow) Asclepias fascicularis (Narrowleaf Milkweed) Baccharis sp. (Coyote brush, Mulefat) Ceanothus sp. (California Lilac) Eriogonum sp. (Buckwheat) Prunis ilicifolia (Hollyleaf Cherry)

Lacewings Ceanothus sp. (California Lilac) Prunus ilicifolia (Hollyleaf Cherry)

Lady beetles Achillea sp. (Yarrow) Asclepias fascicularis (Narrowleaf Milkweed) Atriplex sp. (Quailbush, Saltbush) Ceanothus sp. (California Lilac) Native grasses Rhamnus californica (Coffeeberry) Salix sp. (Willow)

http://www.stopwaste.org/home/index.asp?page=402

Copyright © 2007 Ron Hemberger

http://www.kunafin.com/lacewings.htm

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Know all life phases of

beneficial insects

Don’t use pesticides that will kill the beneficial insects

Larval stage – though ugly - is often the ‘eating’ stage

Look closely at the insects (use a magnifying glass) – what are they eating (plant or insect)

http://www.ipm.ucdavis.edu/PMG/NE/convergent_lady_beetle.html

http://www.ipm.ucdavis.edu/PMG/NE/brown_lacewing.html

http://upload.wikimedia.org/wikipedia/commons/2/2a/Sa_lady-beetle-larva.jpg

Lacewing Life Cycle

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Attract these

beneficial insects

By planting these species

Minute pirate bug

Achillea sp. (Yarrow) Baccharis sp. (Coyote brush, Mulefat) Eriogonum sp. (Buckwheat)

Parasitic & Predatory Wasps

Achillea sp. (Yarrow) Aesclepias fascicularis (Narrowleaf Milkweed) Eriogonum sp. (Buckwheat)

Tachnid flies Achillea sp. (Yarrow) Eriogonum sp. (Buckwheat) Heteromeles arbutifolia (Toyon) Rhamnus californica (Coffeeberry)

http://www.stopwaste.org/home/index.asp?page=402

http://www.ipm.ucdavis.edu/PMG/NE/minute_pirate_bug.html

http://www.ipm.ucdavis.edu/PMG/NE/tachinid_flies.html

Minute Pirate Bug

Tachnid Fly

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Western Yarrow – Achilla millefolia

J.S. Peterson @ USDA-NRCS PLANTS Database

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Why Yarrow makes a good lawn substitute

Spreads quickly, giving good cover

Super for banks and other areas that can’t easily be mowed

Spreading habit inhibits weeds

Can be mowed – occasionally and on high setting w/ rotary mower

Companion plant – attracts beneficial insects, repels others

Does well on poor, dry, sandy soils where other plants grow poorly

http://www.dgsgardening.btinternet.co.uk/yarrow.JPG

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Levels of Control

1. Cultural control is a preventative measure using fertilization, plant selection, and sanitation to exclude problematic pests and weeds.

2. Physical control is another preventative strategy. It includes, pest exclusion; creating barriers; modifying conditions such as temperature, light and humidity; trapping; and manually weeding. Foods and beverages should be eaten and stored only in designated areas.

3. Biological control makes use of a pest's natural enemies. This strategy introduces beneficial insects or bacteria to the environment or, if they already exist, provides them with the necessary food and shelter and avoids using broad-spectrum chemicals that will inadvertently kill them.

4. Chemical control is used after all other control strategies are deemed inappropriate or ineffective. Target-specific, low-toxicity pesticides should be applied in a manner that will maximize the effectiveness of pest management and minimize the exposure to humans and other non-target species. Spot treat if possible to reduce exposure.

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Smothering and suffocation agents - mild

Insecticidal Soap

It works on contact by breaking down the target pest’s cuticle (waxy covering) — promoting dehydration and, ultimately, death.

Short period of action (48 hours)

Non-targeted – kills both beneficial insects as well as pests

Best use: judicious, small-scale spot applications

Safer’s Insecticidal Soap (the most common brand), is used indoors or out, is effective on aphids, cabbageworms, earwigs, flea beetles, lace bugs, leafhoppers, mealybugs, psyllids, sawfly larvae, scale crawlers, squash bugs, thrips, spider mites, whiteflies, and more.

http://ecx.images-amazon.com/images/I/51z2EPV-efL._SL500_AA280_.jpg

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Smothering and suffocation agents - mild

Horticultural Oil

Coating pests with horticultural oil blocks the passage of air through their spiracles (breathing holes), thus killing (suffocating) them.

Used on dormant plants (see label for specific product)

labeled for use against overwintering eggs of European red spider mites, scale insects, apple aphids (not rosy aphids), bud moths, leafrollers, red bugs, codling moth larvae, pear psylla (adults), blister mites, galls, whitefly nymphs, and mealybugs.

http://greenmethods.com/site/products/biorationals/3/#ip

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Sucking insects of spring/summer: review

Monitor Periods of new foliage/rapid growth Monitor at least weekly Look particularly at undersides of leaves, young branch tips, flower

buds – be sure to use a magnifying glass

Cultural Practices Blast affected area with water Hand remove Encourage natural predators Control ants

Biological Controls Beneficial insects – your best line of defense

Chemical controls Not usually needed (except for very bad infestations – not often seen

with native plants) May kill beneficial insects – so use very sparingly Try least toxic: Insecticidal soap

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Ah, Summer….. the time of dusty leaves & over-watering

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10 years old. Almost no water other than a dust wash off every month or so.

Arctostaphylos 'Carmel Sur’ in foreground, Toyon and Western Redbud behind.

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Challenges of the dry season

Dry, dusty foliage

Hot, muggy (or foggy) days

Appropriate watering: How frequently

How much at any one time

How to water: overhead, drip/trickle

What time of day to water The stage is set for a different

cast of garden pests

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Toyon/California Christmas Berry – Heteromeles arbutifolia

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Natives in the Rose Family (Rosaceae)

Shrubs

Chamise - Adenostoma fasciculatum Mountain Mahogonies - Cercocarpus species Toyon - Heteromeles arbutifolia Creambush - Holodiscus discolor Ironwoods - Lyonothamnus floribundus Holly-Leafed & Catalina Cherries - Prunus ilicifolia CA Wild Rose - Rosa californica CA Blackberry - Rubus ursinus

Smaller perennials

Pacific silverweed - Argentina egedii Strawberries - Fragaria species Wedgeleaf Horkelia - Horkelia cuneata

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Common pests of Rose Family (think garden roses)

Pests of new foliage Sucking insects

Pests of summer Pests associated with dust (mostly

insects) Pests associated with warm, moist

conditions (mostly fungal but some bacterial/viral)

Diseases associated with cool, wet conditions: Fungal diseases (foliage & root)

Rosa CA vs. non-native roses It is relatively pest and disease free,

except if the plant is subject to overhead irrigation, poor air circulation and humid conditions in the shade.

Insect pests are usually not a problem with such a hardy plant and with so many “beneficials” around.

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Leafhoppers & Sharpshooters

Leafhoppers are small, green, wedgeshaped insects that attack many garden, forage and fruit crops. They suck out plant juices causing yellowing, leaf-curling and stunting.

Leafhoppers are often responsible for the spread of plant pathogens especially viruses and phytoplasmas

Preventive cultural practices:

Mechanical Controls: blast of water from a garden hose Removing infected lower leaves Dusting plants lightly with

diatomaceous earth

http://pmo.umext.maine.edu/factsht/Suck.htm

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Leafhoppers & Sharpshooters

Biological Controls:

Predatory insects such as mantids and dragonflies

Spiders, green lacewings (Chrysopa spp.), minute pirate bugs (Orius spp.), lady beetles (Hippodamia spp.), and predaceous mites.

Small parasitic wasps in the genus Gonatocerus

Chemical controls:

Narrow range oils, insecticidal soaps, or kaolin clay

rotenone, carbaryl, malathion or methoxychlor

http://pmo.umext.maine.edu/factsht/Suck.htm

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Glassy-winged Sharpshooter – reportable pest

Carry the bacterium, Xylella fastidiosa, that causes Pierce’s Disease – a serious threat to CA grape industry

X. fastidiosa also causes

almond leaf scorch, phoney peach disease, alfalfa dwarf, oleander leaf scorch and citrus variegated chlorosis.

Report to County Ag.

Service if found in new areas

http://www.slocounty.ca.gov/Assets/AG/assets/GWSS2.gif

Adults are about 1⁄2 inch long

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Pierce’s Disease: many native plants are

alternate hosts

Aesculus californica Artemisia douglasiana Heteromeles arbutifolia Juglans californica Mimulus aurantiacus Oenothera hookeri Philadelphus lewisii Populus fremontii Quercus spp. Rhammus californica Rosa californica Salix spp. Sambucus spp. Vitis californica

Blue Elderberry

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Thrips Tiny insects with fringed wings. They feed on pollen and tender plant tissue, rasping the tissue and sucking the exuding sap.

The leaves take on a silvery appearance after the thrips feed, and plants become stunted and deformed.

Thrips are usually a pest of seedling plants but may attack plants in any stage. They attack an extremely wide variety of woody plants.

Certain thrips species are beneficial predators that feed only on mites and other insects

Monitoring:

Thrips often feed within buds and furled leaves. Their damage is often observed before the thrips are seen.

Discolored or distorted plant tissue or black specks of feces around stippled leaf surfaces are clues that thrips are or were present.

Look carefully for the insects themselves before taking action. Severe infestation foliage looks silver-spotted

Thrips are poor fliers but can readily spread long distances by floating with the wind or being transported on infested plants.

http://pmo.umext.maine.edu/factsht/Suck.htm

http://mrec.ifas.ufl.edu/LSO/images/Thrips/ffa2-34.jpg

http://www.gardenseeker.com/plant_pests_problems/plant-pests/thrips_storm_flies.htm

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Thrips – mostly just ugly…

Healthy woody plants usually tolerate thrips damage; however, high infestations on certain herbaceous ornamentals and developing fruits or vegetables may justify control

Preventive cultural practices: Practices to conserve natural predators;

decrease dust, no pesticides Pull weeds Prune and destroy infected branches

Mechanical Controls: Blast of water from a garden hose

Biological Controls: Many natural predators

Chemical controls: thrips activity does not usually warrant the use of insecticide sprays Narrow-range oil, neem oil, pyrethrins combined

with piperonyl butoxide (Garden Safe Brand Multi-purpose Garden Insect Killer, Spectracide Garden Insect Killer)

Malathion or rotenone only for severe problems

http://chillithrips.tamu.edu/

http://virtual.clemson.edu/groups/hort/homeh

ort/images/thrips.jpg

Toyon Thrips

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Gall & Blister Mites: ugly but not killers

Cause blistered leaves or galled twigs on many landscape plants including alder, aspen, baccharis, beech, elm, grape, linden, maple, and walnut

Monitoring:

Misshapen leaves

Preventive cultural practices:

Remove damaged leaves

Mechanical Controls:

Remove damaged leaves

Live oak erineum mites

Baccharis gall

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Spider Mites are tiny

Not insects, but closely related to ticks and chiggers. They suck out juices from leaves and stems, causing plants to become deformed or have a bronze or yellow appearance

Heavy infestations can cause leaf and bud drop, serious stress and death of the plant.

Damaged areas typically appear marked with many small, light flecks – over slightly cobwebby - giving the plant a somewhat speckled appearance.

Activity peaks during the warmer months; Dry, dusty conditions favor all spider mites

Monitoring: Usually plant damage—stippling or yellowing of

leaves Look for webbing underneath leaves Shake mites onto paper & observe with hand

lens

http://pmo.umext.maine.edu/factsht/Suck.htm

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7405.html

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Spider Mites: prevention is best

Preventive cultural practices: Wash dust off leaves in summer Don’t use insecticides (carbaryl (Sevin);

imidacloprid (Merit, Marathon) ) that kill natural predators; severe infestations often follow insecticide use!

Mechanical Controls: blast of water from a garden hose 1:1 mixture of alcohol and water [test on small area] Plant isolation

Biological Controls: Small, dark-colored lady beetles known as the

"spider mite destroyers" Minute pirate bugs, big-eyed bugs (Geocoris

species) and predatory thrips Parasitic spider Mites

Chemical controls: not during hot weather or for water stressed plants – test first on a few leaves Insecticidal soap Horticultural oils (Sunspray) Sulfur

http://pmo.umext.maine.edu/factsht/Suck.htm

Few insecticides are effective for spider mites and many even aggravate problems

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Chewing insects are

also active in summer

Definition: Chewing insects eat plant tissue such as leaves, flowers, buds, and twigs.

Indications of damage: uneven or broken margins on the leaves, skeletonization of the leaves, and leaf mining.

The damage they cause (leaf notching, leaf mining, leaf skeletonizing, etc.) will help in identifying the pest insect.

Examples: beetle adults or larvae, moth larvae (caterpillars) many other groups of insects.

Cabbage Looper

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Is it a sucking or a chewing pest?

Sucking pests, such as aphids, leafhoppers, scale insects and whiteflies, produce these symptoms:

• Discoloration (yellow or brown) and necrotic (dead) spots on leaves or petals;

• Wilted appearance of plant or plant parts; • Curled, malformed leaves and petals; and • Shiny, sticky “honeydew” or black-colored

coating of sooty mold.

Chewing pests, such as caterpillars, beetles, grasshoppers and leaf-cutter bees, produce these symptoms:

• Holes in foliage or stems; • Discolored areas on the surface or margins

of leaves or petals; • Severed stems, leaves or buds or wilting of

stem or cane (limb girdling); • Wilting of plant (root damage by white

grubs or other root feeders); and • Semicircular holes in leaf margins (leaf-

cutting bees).

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Botanical pesticides: natural but not

harmless for control of chewing insects

Pyrethrum is extracted from the flowers of a chrysanthemum grown in Kenya and Ecuador. It is one of the oldest and safest insecticides available. Mode of action — Pyrethrum (and synthetic pyrethrum) paralyze insect’s nervous system. Used for – aphids, scale insects, spider mites, thrips, caterpillars and many other leaf-

feeding pests

Rotenone or rotenoids are produced in the roots of two genera of the legume family: Derris and Lonchocarpus (also called cubé) grown in South America. Mode of action: shuts down cellular metabolism It is both a stomach and contact insecticide; toxic to many species of insects in many

different insect orders (caterpillars, beetles, flies, etc.). Mild human toxicity; ? Risk for Parkinson’s Disease

Eugenol (Oil of Cloves) and Cinnamaldehyde (derived from Ceylon and Chinese cinnamon oils). Mode of action – similar to Pyrethrum Used for: chewing insects like beetles – but general insecticide

Nicotine is extracted by several methods from tobacco Mode of action – nervous system conduction; convulsions, death effective against most all types of insect pests, but is used particularly for aphids and

caterpillars--soft bodied insects.

EcoSMART™ plant oil-based pesticides

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Neem Oil/ Azadiractin

Neem oil extracts are squeezed from the seeds of the neem tree and contain the active ingredient azadirachtin

Rather sensational insecticidal, fungicidal and bactericidal properties, including insect growth regulating qualities.

Mode of action--Azadirachtin disrupts molting by inhibiting biosynthesis or metabolism of ecdysone, the juvenile molting hormone.

Used for: Azatin® is marketed as an insect growth

regulator, and Align® and Nemix® as a stomach/contact insecticide for greenhouse and ornamentals.

Many leaf chewing insects including Gypsy moth larvae, imported cabbage worms, leafminer species’ larvae and pupae, various leafrollers, various loopers, grasshoppers, beetles, mealybug species’ immatures, sawfly larvae, sweet potato and silverleaf whitefly immatures, and webworms

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Read & follow

directions

http://rayssupplycompany.com/index.php?main_page=index&manufacturers_id=42

Mix pesticides according to label instructions. Don’t use more or less concentrate than the label recommends. Mix only as much material as you need for the application.

Wear protective clothing as specified on the label.

Label a set of mixing and measuring tools that are used only for insecticides and fungicides, and store them with the products.

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More pesticide safety tips

Keep pets and people away from the area where you store, mix, and apply pesticides. Stay away from a treated area for as long as the label directs.

Do not spray on a windy day or when air temperatures will be above 85°F before the spray solution dries.

Clean equipment and mixing tools as soon as you finish spraying.

Dispose of pesticides properly

After spraying, change your protective clothing and bathe. Wash the clothes you were wearing separately from your regular laundry.

Keep records of where and when you sprayed, what pesticide you used, and how much you used. Give the treatment time to work, then evaluate and record your results.

http://www.gemplers.com/img/pesticide-storage-area-126066.jpg

http://www.ipm.ucdavis.edu/WATER/U/storedispose.html

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Black Spot - Diplocarpon rosae fungus

Occurs during warm, damp/humid weather; spores overwinter in infected canes & fallen leaves

Preventive cultural practices: Provide good air circulation, appropriate sunlight conditions Don’t over-water; no overhead irrigation Remove & dispose of infected leaves; don’t handle plants when foliage is wet Cut back & dispose of infected canes; dispose of fallen leaves

Chemical controls: fungicides – copper, sulfur & Neem Oil

http://www.extension.umn.edu/distribution/horticulture/DG1163.html

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Currants & Gooseberries – Ribes spp

Pink-flowering Currant - Ribes sanguineum

White-flowering Currant - Ribes indecorum

Chaparral Currant - Ribes malvaceum

Catalina Perfume - Ribes viburnifolium

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Common pests/diseases of Ribes species

Fungal Diseases Leaf Spot or

Anthracnose

Cane Blight

Powdery Mildew

Rusts

Virus and Virus-like Diseases

Insects & Mites Sucking insects

Gall formers

Stem borers

http://www.ars-grin.gov/cor/ribes/ribsymp/ribsymp.html

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The ‘Disease Triangle’ – the key to

understanding plant pests & diseases

Proper environment Warm, wet conditions

Overhead watering

Poor air circulation

Cultural (prevention) controls are mostly about making the environment inhospitable

Currant

Fungal species

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Powdery Mildew - Sphaerotheca pannosa

fungus

http://www.extension.umn.edu/distribution/horticulture/DG1163.html

Susceptible: Rose family, Dogwoods, Honeysuckles, Sycamores, Willows, Sunflower Occurs during warm, damp/humid weather; spores overwinter in infected wood &

fallen leaves Preventive cultural practices:

Provide good air circulation, appropriate sunlight conditions Don’t over-water; no overhead irrigation Remove & dispose of infected leaves Cut back & dispose of infected branches; dispose of fallen leaves

Chemical controls: fungicides – copper, sulfur, horticultural oils & Neem Oil

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Rusts – large group of foliage

fungi attacking many plant

species

Occur during warm, damp/humid weather; spores overwinter in infected wood & fallen leaves

Preventive cultural practices: Provide good air circulation,

appropriate sunlight conditions Don’t over-water; no overhead

irrigation Remove & dispose of infected

leaves Cut back & dispose of infected

branches; dispose of fallen leaves

Chemical controls: fungicides – copper, sulfur, horticultural oils & Neem Oil

http://gardeningwebguide.com/GardeningBlog/category/garden-pests/

http://www.omafra.gov.on.ca/english/crops/pub360/notes/rasporustf1.jpg

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Natural Compounds as preventive measures: fungal diseases

Example: Copper-Sulfate Copper-Sulfate Spray or Dust Copper

Bordeaux substitute is an organic fungicide containing 7% copper sulfate (metallic)

Effective in preventing a wide range of various blights, spots, certain rots, downy and powdery mildew, leaf blister, anthracnose, scab, stem canker, Septoria spp. and Stemphylium spp. leaf molds and more.

No insecticidal qualities, and will not burn plants.

Must be applied early (when plants dormant)

Appropriate cultural practice for fungal prone species like Currants

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Fungal Canker

Diseases

Cause: several types of fungi that invade bark injuries & infect connective tissues of trunk

Monitoring: a killed area or blister on the bark, a branch or the trunk of an infected tree. May ooze.

Preventive cultural practices: Promote overall tree health;

don’t over-fertilize Prevent trunk/branch

wounds Proper pruning; dormant

season Call an experienced arborist

or County Dept. of Ag.; early treatment can help

http://www.extension.umn.edu/projects/yardandgarden/ygbriefs/p-cankermaple.html

http://www.ext.colostate.edu/Ptlk/1407a.html

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Fireblight - Erwinia amylovora

Bacteria that infects the new spring growth in Rose family

During warm, wet weather the bacteria ooze in brown droplets from cankers and are spread by pollinators and splashing water to the flowers and then to twigs.

Verify the presence of fireblight by peeling back newly infected bark-the wood will have a reddish-brown discoloration.

Prune diseased wood back at least 6 inches into healthy tissue. Entire branches (even whole plants) may need to be removed.

Do not put prunings into a compost pile; dispose of them in the green waste.

Sterilization of the pruning instruments between each cut with a 10% bleach solution.

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7414.html

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Mature trees, when stressed, are

susceptible to stem-boring insects

Drought stress can be avoided by supplemental winter watering when needed

goldspotted oak borer (GSOB)

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Stem Borers: Longhorned borers, bark &

ambrosia beetles, clearwing moths, twig girdlers,

flatheaded borers

Willows, Cottonwood/Poplar, Sycamore, Oak, Juniper, Pine, Ceanothus, currants

Monitoring: particularly for old or stressed trees/shrubs Bark staining Bore holes Frass; pupal cases [Clearwing Moths]

Preventive cultural practices: Encourage vigorous, healthy plants Prevent stem/root injury removing weakened, injured, dying, and

dead trees Mechanical Controls: Biological Controls:

Parasitic nematodes Chemical controls:

http://www.fs.fed.us/r5/cleveland/projects/projects/oa

k-borer/

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Diseases that affect soils

More common in areas previously used for agriculture, vegetable gardening, palm trees

Caused by fungal or bacterial pathogens in the soils

Enter plants via the roots

Very difficult to control – require soil sterilization

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Blights & Branch Die-back

Causes: Verticillium wilt—Verticillium fungi Fusarium wilt - Fusarium fungi Root Rot fungi

Susceptible: Strawberries, caneberries Vegetable crops (tomato) Woody trees (many)

Monitoring: Symptoms: Decline in twig and leaf growth. Dieback in individual twigs and

branches. Foliage becomes light green to chlorotic and then may scorch by midsummer. A discoloration of the inner bark may occur.

Leaves on one or more branches suddenly wilt, turn light tan, and die. Dead leaves generally remain on the tree throughout the growing season.

http://www.ipm.ucdavis.edu/PMG/GARDEN/FRUIT/DISEASE/verticilliumwil.html

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Blights & Branch Die-back

Preventive cultural practices:

Keep plants healthy; don’t stress by over- or under watering

Remove Verticillium-susceptible weeds, such as lamb's quarters, amaranth (pigweed), nightshade

Remove and dispose of affected plants, including roots

Solarize affected soils

Chemical controls: consult a licensed arborist or County Agent

Oak Twig Blight

http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/DISEASES/oak

brdieback.html

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Root, collar & crown rots

A large number of root rots are caused by members of the water mould genus Phytophthora.

Favored by high soil moisture and soil temperatures in poorly drained soils.

More common in soils with prior Azaleas, Avocado, Citrus

Monitoring:

Plants wilt at midday and may recover at night (ultimately, plants yellow and die).

In trees, sparse growth and slow decline.

Feeder roots have blackened tips, brown streaks or appear to be rotting.

Mushrooms around tree base indicate final stages.

http://www.ca.uky.edu/agcollege/plantpathology/ext_files/PPFShtml/PPFS-OR-W-5.pdf

http://www.ces.ncsu.edu/depts/pp/notes/oldnotes/odin13/od13a.htm

Brown streaks on roots

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Root/collar/crown rots

Preventive cultural practices:

Proper drainage and irrigation, particularly in clay soils; consider berming to increase drainage

Choose species that can tolerate poorly-drained soils

Never cover root collar with dirt or mulch

Don’t damage roots

Buy only healthy plants

Weed around the tree/shrub

Remove and destroy infected plants, roots

Chemical controls: Call experienced, licensed arborist for infected trees

http://ag.arizona.edu/PLP/plpext/diseases/trees/Ash/GRR2.html

http://www.ces.ncsu.edu/depts/pp/notes/oldnotes/odin13/od13a.htm

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Sudden Oak Death Syndrome - Phytophthora ramorum

Kills CA native oaks and other trees/shrubs in N. CA & OR (for now)

Toyon (Heteromeles arbutifolia), Coffeeberry (Rhamnus californica), CA Buckeye and Honeysuckle (Lonicera hispidula) and others are susceptible. Disease symptoms have not been well characterized on these hosts at this time.

Leaf lesions are characteristically round with a bulls-eye appearance of alternating light and dark rings

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Evergreen huckleberry Vaccinium ovatum

California buckeye Aesculus californica

A number of other native broad-leaf species harbor Phytophthora ramorum in California and Oregon (See the complete list in Part 1.). Little is known about the role of these species in the life cycle and spread of the disease. The pathogen is difficult to culture from many of these species, and is difficult to diagnose because of the presence of other foliar diseases.

Toyon Heteromeles arbutifolia

Bigleaf maple Acer macrophyllum

California honeysuckle Lonicera hispidula

Pacific madrone Arbutus menziesii

Wood rose Rosa gymnocarpa

All photos: Garbelotto Lab, UC Berkeley http://www.suddenoakdeath.org/ppt/Virtual%20Training%20Part%202.ppt#324,8,Slide 8

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And now we’re back to the rainy season…

….with it’s own unique set of pest challenges

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Snails & slugs

http://extension.oregonstate.edu/news/images/snail.jpg

http://i.dailymail.co.uk/i/pix/2008/06/18/article-1027544-01A4B50C00000578-51_468x315.jpg

http://farm2.static.flickr.com/1257/942909073_87997125e8.jpg?v=0

Preventive cultural practices: Don’t over-water Remove dead leaves from

ground

Mechanical Controls: Mechanical picking Trapping: under boards or

newspapers Pans of beer or sugar water Copper bands (for tree

trunks)

Biological Controls: Encourage birds, toads

Chemical controls: ‘Non-toxic’ Iron phosphate

snail bait – ‘Sluggo’ brand

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Sycamore anthracnose - Gnomonia leptostyla

The only serious disease of sycamores; will not kill

the tree.

Common in cool wet weather of spring.

Monitoring: First symptoms appear on young leaves as they unfold. Older leaves turn brown, and dead areas occur along

the leaf veins. Brown areas eventually include the whole leaf.

The ends of twigs may be killed back 8 to 10 inches. Cankers may develop on the tree trunk and main

branches

Preventive cultural practices: Proper tree spacing and pruning to promote good air

circulation Gather and destroy all fallen leaves and twigs. Prune out all infected twigs and branches and destroy

them. Remove the dead, cankered tissue down to healthy wood.

Dry winters weaken trees, increasing the effects of diseases. To reduce this problem, water trees once a month during dry winters.

Chemical controls: Chemical sprays normally are not necessary to control

anthracnose

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So, go out to your garden and get to know it’s insects