Garden Pests - notes


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Garden Pests - notes

  1. 1. 1/7/2013Out of the Wilds and Into Your Garden Pests, Pests, Pests C.M. Vadheim and T. Drake CSUDH & Madrona Marsh Preserve Madrona Marsh Preserve Gardening with Western L.A. County Native Plants March 7 & 10, 2009 Project SOUND - 2009 © Project SOUND © Project SOUNDWhat is a pest?  An organism which has Predator/prey relationships in nature 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’ © Project SOUND © Project SOUND 1
  2. 2. 1/7/2013In nature, plants fight back… A recipe for disaster  Native plants evolved with insects, other  Plant species not native to animals, microorganisms area; often ‘cultivars’ – ecosystems in balance  Some produce  Planted in mono-culture noxious chemicals or physical barriers to  Heavily watered & ‘ward off’ natural fertilized – ‘plants on pests steroids’  Some attract  Using overhead watering ‘helper species’ – insects & even birds during warm summer days  Some simply tolerate normal levels of predation  Globalization of pests © Project SOUND © Project SOUND The ‘Old California Garden’ requires an arsenal of ammunition… And the consequences are not pretty…  Human/animal health risks  Contaminated soils & water (including street water runoff) /792923315-spray-doc-wheel-garden-sprayers.html  High cost of pesticides  Beneficial species killed Issues:  Improper use  Effects on animals up the food chain  Overuse  Pesticide resistance  Storage © Project SOUND © Project SOUND 2
  3. 3. 1/7/2013 Many of us have found that just including more The ‘New California Garden’ is based on native species improves the ‘pest problems’ in the a better strategy entire garden 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 © Project SOUND © Project SOUND But you need to have a sound strategy to dealing with certain pests…even on native plants 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) And that’s where the concept of Integrated Pest Management (IPM) provides useful guidelines © Project SOUND © Project SOUND 3
  4. 4. 1/7/2013 The IPM Pyramid – ‘first do no harm’ What is Integrated Pest Management?  Use the least invasive – and often most effective - means first: IPM programs use current, comprehensive  Prevention – cultural practices  Mechanical Controls information on the life cycles of pests and their  Naturally occurring biological interaction with the environment. controls (native predators)  Consider using non-native This information, in combination with available predators pest control methods, is used to manage pest  Use chemical controls sparingly, damage by the most economical means, and with as a last resort:  Naturally occurring elements the least possible hazard to people, property, and  Biologics – chemicals made by the environment.’ Non-native predators and chemical plants that are toxic to controls have the important drawback of pests/diseases non-specificity – they kill the good pests  Non-biologic pesticides: with the bad.  Insecticides  Fungicides  Miticides © Project SOUND © Project SOUND An IPM system is designed around sixSome of the benefits of an integrated basic componentsapproach are as follows: 1. Set Action Thresholds  Before taking any pest control action, IPM first sets an action  Promotes natural controls; ‘ecosystem approach’. threshold, a point at which pest populations or environmental conditions indicate that pest control action must be taken. Sighting  Protects human health. 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.  Minimizes negative impacts to non-target organisms. 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  Enhances the general environment. 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  Is most likely to produce long-term, beneficial the possibility that pesticides will be used when they are not really results. needed or that the wrong kind of pesticide will be used. 3. Preventive Cultural Practices  Often is easily and efficiently implemented.  As a first line of pest control, IPM programs work to manage the crop, lawn, or indoor space to prevent pests from becoming a  Cost-effective in the short and long-term. threat. These control methods can be very effective and cost- efficient and present little to no risk to people or the environment. © Project SOUND © Project SOUND 4
  5. 5. 1/7/2013 An IPM system is designed around six IPM plan for your garden – a work in basic components progress4. Mechanical controls: Should a pest reach an unacceptable level,  Requires observation & mechanical methods are the first options to consider. They knowledge – specific for include simple hand-picking, erecting insect barriers, using traps, vacuuming, and tillage to disrupt breeding. your garden5. Biological controls: Natural biological processes and materials can  Will vary somewhat with: provide control, with minimal environmental impact, and often at low cost. The main focus here is on promoting beneficial insects  Yearly weather conditions that eat target pests. Biological insecticides, derived from  Maturity of plants naturally occurring microorganisms (e.g.: Bt, entomopathogenic fungi and entomopathogenic nematodes), also fit in this category.  New plants6. Chemical controls: Synthetic pesticides are generally only used  Will be modified based on as required and often only at specific times in a pests life cycle. your previous experiences Many of the newer pesticide groups are derived from plants or naturally occurring substances (e.g.: nicotine, pyrethrum and  Suggestion: keep a garden insect juvenile hormone analogues), and further biology-based or ecological techniques are under evaluation. notebook/journal © Project SOUND © Project SOUND Many resources to help you University of California Statewide IPM Project (UCIPM)  Books – check out your  Goals of the IPM Project are to: local library, or add to your  reduce the pesticide load in the own environment,  increase the predictability and  On-line resources thereby the effectiveness of pest control techniques,  develop pest control programs that  County Master Gardeners are economically, environmentally and socially acceptable,  Other Governmental  marshal agencies and disciplines into resources: (see list) integrated pest management program, and  U.S.  increase the utilization of natural  State & Local pest controls.  Educational component:  Print & on-line resources  UC IPM Pesticide Education Program © Project SOUND © Project SOUND 5
  6. 6. 1/7/2013 Set Acceptable Pest Levels Monitor & Identify Pests  Find out what pests/  Base monitoring on garden conditions: temperature & diseases occur in your humidity garden – observation  Look for pests on vulnerable tissues  Learn more about the pests,  Shake out the pests, then view with magnifying glass their effects  Decide if action is needed  What are their life-stages  Suggestion: keep a log of dates,  What seasons/conditions are conditions in your garden journal they associated with  What plant species are susceptible  Learn how to determine when action should be taken © Project SOUND © Project SOUND Prevention/Cultural Practices are the first Criteria for selecting a treatment line of defense against pests strategy are:  Cultural practices: just good old garden management practices 1. Least hazardous to human health  Providing alternate hosts for pests  No monoculture 2. Least disruptive of natural controls  Preventing over-wintering  Sanitation 3. Least toxic to non-target organisms  Proper water & nutrient management 4. Most likely to be permanent  Correct watering  Physical barriers 5. Easiest to carry out safely and effectively  Pruning to improve air circulation  Weeding 6. Most cost-effective  Mulching 7. Most site-appropriate © Project SOUND © Project SOUND 6
  7. 7. 1/7/2013 Pest challenges vary with the season…. Sticky (Bush) Monkey Flower - Mimulus/Diplacus aurantiacus  Warmer weather & new growth – spring/early summer  Sucking insects  Chewing insects  Gall & Blister Mites  Warm weather – summer/fall  Foliage fungal diseases  Borers (insects) Scarlet Monkeyflower  Root/stem rots Musk Monkeyflower (fungal/bacterial)  Cool, wet weather – winter/early spring  Mollusks  Anthracnose (fungal) © Project SOUND © Project SOUND Sucking insects Any perennial or shrub/tree with fresh  Definition: Insects that insert their mouthparts into the sugary phloem (conducting tissue) & suck new foliage can attract sucking insects 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 © Project SOUND © Project SOUND 7
  8. 8. 1/7/2013 Aphids: where there’s one there are many….. Aphids – Ugly but not usually murderers...  Often called plant lice, are small,  Preventive cultural soft-bodied insects. practices:  Control ants  They range in color from black to http://pmo.umext.maine.  Control weeds – green to yellow. edu/factsht/Suck.htm particularly Brassica species  Their numbers may greatly increase in a short time and  Mechanical Controls: crowding stimulates the  Blast off with a stream of production of winged forms. water  Use sticky strips around  They may cover the entire trunks to manage ants surface of a leaf or stem.  Biological Controls:  They (and other sucking pests)  Lady bugs; Lacewings can be vectors of plant viruses (crop & ornamental plants).  Chemical controls:  Insecticidal Soap is usually  They can also weaken plants, adequate making them susceptible to other diseases © Project SOUND © Project SOUND Whiteflies Monitor particularly on citrus and  Monitoring: vegetable crops (and plants near them)  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 Ash Whitefly (Siphoninus phillyreae)  Biological Controls: nty.htm can attack Toyon & other natives  Ladybugs, Lacewings, parasitic wasps & mites Wooly Whitefly on Citrus  Songbirds  Chemical controls:  Insecticidal Soap  Chemical pesticides usually not very helpful –  Mechanical methods and encouraging natural enemies offer best resistance quickly develops chance for control © Project SOUND © Project SOUND 8
  9. 9. 1/7/2013  Females feed on plant sap, normally in roots or other crevices. They secrete a powdery wax Controlling aphids, whiteflies & Mealybugs is an Mealybugs layer (therefore the name mealybug) used for important ‘cultural practice’ for preventing other diseases protection while they suck the plant juices.  Monitoring:  Check stem axils & bottoms of plant stems for insects  Mealybugs are similar to  Act immediately when you see them to control whiteflies and aphids: they infestation produce large amounts of waste product (honeydew)  Preventive cultural practices: which coats plants and  Insect new plants – remove pests surrounding surfaces.  Control ants (which protect Mealybugs)  Encourage natural predators  This sticky layer is a perfect  Mechanical Controls: growth medium for a black  Remove by hand & destroy Sooty Mold fungus commonly known as  Apply rubbing alcohol with a Q-tip or cotton "sooty mold". ball; destroys insects & egg masses [note: try on small area first – may damage plant]  This mold damages plants by covering leaves and reducing  Biological Controls: light available for  Lady Bug, Lacewings, parasitic wasps –all natural photosynthesis.  Chemical controls:  Insecticidal Soap or horticultural oils © Project SOUND © Project SOUND Good natural enemies are there – just True Bugs plant species that will attract them  Many are actually beneficial predators  Green Lacewing  Common generalist predator  Preventive cultural practices:  Kills: mealybugs, psyllids, thrips,  Encourage healthy plants mites, whiteflies, aphids, small caterpillars, leafhoppers, and Green Lacewing insect eggs  Chemical controls: not recommended in most cases  Use common pesticides & you’ll kill this beneficial insect You will need to learn about  Plant species in the Rose & Milkweed Bug the common beneficial insects in order to recognize Buckthorn (Ceanothus) families to and attract them provide food for Lacewings © Project SOUND © Project SOUND 9
  10. 10. 1/7/2013 Attract Know all life phases of these By planting beneficial these species beneficial insects insects Bigeyed bug Native grasses  Don’t use pesticides that will kill the Polygonum sp. (Silver Lace Vine) beneficial insects Copyright © 2007 Ron Hemberger Hoverflies Achillea sp. (Yarrow)  Larval stage – though ugly - is often the Asclepias fascicularis (Narrowleaf Milkweed) ‘eating’ stage Baccharis sp. (Coyote brush, Mulefat) Ceanothus sp. (California Lilac)  Look closely at the insects (use a Eriogonum sp. (Buckwheat) magnifying glass) – what are they eating Prunis ilicifolia (Hollyleaf Cherry) (plant or insect) Ceanothus sp. (California Lilac) Lacewings 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) © Project SOUND © Project SOUND Lacewing Life Cycle Attract these By planting Western Yarrow – Achilla millefolia beneficial these species insects Minute Achillea sp. (Yarrow) pirate bug Baccharis sp. (Coyote brush, Mulefat) Eriogonum sp. (Buckwheat) Minute Pirate Bug Achillea sp. (Yarrow) Parasitic & Aesclepias fascicularis (Narrowleaf Predatory Milkweed) Wasps Eriogonum sp. (Buckwheat) Tachnid flies Achillea sp. (Yarrow) Eriogonum sp. (Buckwheat) Heteromeles arbutifolia (Toyon) Rhamnus californica (Coffeeberry) Tachnid Fly © Project SOUND © Project SOUND J.S. Peterson @ USDA-NRCS PLANTS Database 10
  11. 11. 1/7/2013Why Yarrow makes a good lawn substitute Levels of Control 1. Cultural control is a preventative measure using fertilization, plant selection, and sanitation to exclude problematic pests  Spreads quickly, giving good and weeds. cover 2. Physical control is another preventative strategy. It includes, pest exclusion; creating barriers; modifying conditions such  Super for banks and other areas as temperature, light and humidity; trapping; and manually that can’t easily be mowed weeding. Foods and beverages should be eaten and stored only in designated areas.  Spreading habit inhibits weeds 3. Biological control makes use of a pests natural enemies. This  Can be mowed – occasionally and strategy introduces beneficial insects or bacteria to the on high setting w/ rotary mower environment or, if they already exist, provides them with the necessary food and shelter and avoids using broad-spectrum  Companion plant – attracts chemicals that will inadvertently kill them. beneficial insects, repels others 4. Chemical control is used after all other control strategies are  Does well on poor, dry, sandy deemed inappropriate or ineffective. Target-specific, low- soils where other plants grow toxicity pesticides should be applied in a manner that will poorly maximize the effectiveness of pest management and minimize the exposure to humans and other non-target species. Spot treat if possible to reduce exposure. © Project SOUND © Project SOUND Smothering and suffocation agents - mild Smothering and suffocation agents - mild  Insecticidal Soap  Horticultural Oil  It works on contact by breaking down the target pest’s cuticle (waxy  Coating pests with horticultural oil covering) — promoting dehydration and, blocks the passage of air through ultimately, death. their spiracles (breathing holes),  Short period of action (48 hours) thus killing (suffocating) them.  Non-targeted – kills both beneficial insects as well as pests  Used on dormant plants (see label for specific product)  Best use: judicious, small-scale spot applications  labeled for use against overwintering  Safer’s Insecticidal Soap (the most eggs of European red spider mites, common brand), is used indoors or out, is effective on aphids, cabbageworms, scale insects, apple aphids (not rosy earwigs, flea beetles, lace bugs, aphids), bud moths, leafrollers, red leafhoppers, mealybugs, psyllids, sawfly bugs, codling moth larvae, pear psylla larvae, scale crawlers, squash bugs, thrips, spider mites, whiteflies, and (adults), blister mites, galls, whitefly more. nymphs, and mealybugs. © Project SOUND © Project SOUND 11
  12. 12. 1/7/2013Sucking insects of spring/summer: review Ah, Summer….. the time of dusty leaves & over-watering 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 © Project SOUND © Project SOUND 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 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. © Project SOUND © Project SOUND 12
  13. 13. 1/7/2013 Toyon/California Christmas Berry – Heteromeles arbutifolia 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 © Project SOUND © Project SOUNDCommon pests of Rose Family (think Leafhoppers & Sharpshootersgarden roses)  Pests of new foliage  Leafhoppers are small, green,  Sucking insects wedgeshaped insects that attack many  Pests of summer garden, forage and fruit crops. They  Pests associated with dust (mostly suck out plant juices causing yellowing, insects) leaf-curling and stunting.  Pests associated with warm, moist conditions (mostly fungal but some bacterial/viral)  Leafhoppers are often responsible for the spread of plant pathogens  Diseases associated with cool, wet especially viruses and phytoplasmas conditions:  Fungal diseases (foliage & root)  Preventive cultural practices:  Rosa CA vs. non-native roses  Mechanical Controls:  It is relatively pest and disease free, except if the plant is subject to  blast of water from a garden hose overhead irrigation, poor air circulation  Removing infected lower leaves and humid conditions in the shade.  Insect pests are usually not a problem  Dusting plants lightly with with such a hardy plant and with so diatomaceous earth many “beneficials” around. © Project SOUND © Project SOUND 13
  14. 14. 1/7/2013 Leafhoppers & Sharpshooters Glassy-winged Sharpshooter – reportable pest  Biological Controls:  Carry the bacterium,  Predatory insects such as mantids and Xylella fastidiosa, that dragonflies causes Pierce’s Disease – a serious threat to CA  Spiders, green lacewings (Chrysopa spp.), grape industry minute pirate bugs (Orius spp.), lady beetles (Hippodamia spp.), and predaceous mites. Adults are about 1⁄2 inch long  X. fastidiosa also causes almond leaf scorch,  Small parasitic wasps in the genus phoney peach disease, Gonatocerus alfalfa dwarf, oleander  Chemical controls: leaf scorch and citrus variegated chlorosis.  Narrow range oils, insecticidal soaps, or kaolin clay  Report to County Ag.  rotenone, carbaryl, malathion or Service if found in new methoxychlor areas © Project SOUND © Project SOUND Tiny insects with fringed wings. They feed on Pierce’s Disease: many native plants are Thrips  pollen and tender plant tissue, rasping the tissue and sucking the exuding sap. alternate hosts  The leaves take on a silvery appearance after the thrips feed, and plants become stunted and  Aesculus californica deformed.  Artemisia douglasiana  Thrips are usually a pest of seedling plants but  Heteromeles arbutifolia may attack plants in any stage. They attack an extremely wide variety of woody plants.  Juglans californica  Mimulus aurantiacus  Certain thrips species are beneficial predators  Oenothera hookeri that feed only on mites and other insects  Philadelphus lewisii  Monitoring:  Populus fremontii  Thrips often feed within buds and furled leaves.  Quercus spp. Their damage is often observed before the thrips are seen.  Rhammus californica  Discolored or distorted plant tissue or black  Rosa californica specks of feces around stippled leaf surfaces are clues that thrips are or were present.  Salix spp.  Look carefully for the insects themselves before  Sambucus spp. taking action. Severe infestation foliage looks silver-spotted  Vitis californica  Thrips are poor fliers but can readily spread long distances by floating with the wind or being transported on infested plants. Blue Elderberry © Project SOUND © Project SOUND 14
  15. 15. 1/7/2013 Thrips – mostly just ugly… Gall & Blister Mites: ugly but not killers  Healthy woody plants usually tolerate thrips damage; however, high infestations on certain herbaceous ornamentals and developing fruits or vegetables may justify control  Cause blistered leaves or galled twigs on many landscape plants  Preventive cultural practices:  Practices to conserve natural predators; including alder, aspen, baccharis, decrease dust, no pesticides beech, elm, grape, linden, maple,  Pull weeds  Prune and destroy infected branches and walnut  Mechanical Controls: Live oak erineum mites  Monitoring:  Blast of water from a garden hose  Misshapen leaves  Biological Controls:  Preventive cultural practices: ort/images/thrips.jpg  Many natural predators  Remove damaged leaves  Chemical controls: thrips activity does not usually warrant the use of insecticide sprays  Mechanical Controls:  Narrow-range oil, neem oil, pyrethrins combined with piperonyl butoxide (Garden Safe Brand  Remove damaged leaves Multi-purpose Garden Insect Killer, Spectracide Garden Insect Killer)  Malathion or rotenone only for severe problems Toyon Thrips © Project SOUND Baccharis gall © Project SOUND Spider Mites are tiny Spider Mites: prevention is best  Not insects, but closely related to ticks and  Preventive cultural practices: chiggers. They suck out juices from leaves  Wash dust off leaves in summer and stems, causing plants to become  Don’t use insecticides (carbaryl (Sevin); imidacloprid (Merit, Marathon) ) that kill natural deformed or have a bronze or yellow predators; severe infestations often follow appearance insecticide use!  Heavy infestations can cause leaf and bud  Mechanical Controls: drop, serious stress and death of the plant.  blast of water from a garden hose  1:1 mixture of alcohol and water [test on small area]  Damaged areas typically appear marked with  Plant isolation many small, light flecks – over slightly cobwebby - giving the plant a somewhat  Biological Controls: speckled appearance.  Small, dark-colored lady beetles known as the "spider mite destroyers"  Activity peaks during the warmer months;  Minute pirate bugs, big-eyed bugs (Geocoris Dry, dusty conditions favor all spider mites species) and predatory thrips  Parasitic spider Mites  Monitoring:  Chemical controls: not during hot weather or for  Usually plant damage—stippling or yellowing of water stressed plants – test first on a few leaves leaves Few insecticides are  Insecticidal soap  Look for webbing underneath leaves effective for spider mites and many even  Horticultural oils (Sunspray)  Shake mites onto paper & observe with hand aggravate problems  Sulfur lens © Project SOUND © Project SOUND 15