IPM For Greenhouse and Nursery Crops

Marion Murray Utah State University Extension

Utah Green Conference 2010 Topics Integrated Pest Management Techniques

Insect Pests ▫ Aphids ▫ Fungus gnats ▫ Whiteflies ▫ Thrips ▫ Spider mites ▫ Borers

Diseases ▫ Root rots ▫ Botrytis

On‐line Resources Why use IPM? Resurgence ▫ pestic ides may kill natltural enemies, ldileading to increase in population

Secondary pest outbreak ▫ some pesticides promote pest activity: x carbaryl is known to increase spider mite reproduction x trees treated with imidacloprid (Marathon) have been shown to have greater mite problems x pyrethroids used early in the season also kill predatory mites, leading to mite outbreaks later on Residues from contact pesticides

Resistance ▫ whiteflies ▫ thrips • Availability ▫ possible removal/la be l change of many pestic ides, for example acephate, chlorpyrifos

• Costs

• Public Pressure IPM Definition

"IPM is a sustainable approach to managing pests by combining biological, cultural, physical and chemical tools in a way that minimizes economic, health, and environmental risks.“ Comppgonents of an IPM Program • Knowledge of pest biology and behavior as well as knowledge of host plant

• Scout for or disease occurrence Why Scout? HELP MAKE PEST MANAGEMENT DECISIONS

▫ provides early warning of potential pest problems

▫ help time control measures properly

▫ provides immediate feedback about whether pest control activities are working

▫ historical data measures effectiveness of management Scoutinggy: Sticky Traps

Placement ▫ At least 1 card per 1,000 sq ft

▫ Check and replace weekly & after a treatment aphids ▫ 1‐2 inches above plant canopy, near fungus gnats favored hosts whiteflies

▫ Reduce number if releasing winged beneficial thrips ▫ Eliminate blue traps if using bumble bees for pollination Identifyyging Insects on Stickyyp Traps

Aphids Thrips Segmented antennae

Parallel veins Feathery Legs & antennae long and wings thin Long slender body Identifyyging Insects on Sticky Traps

Fungus gnats Whiteflies

Long antennae Y‐shaped vein

White wax dissol ves in adhesive; orange underneath Small, dark, mosquito‐ like flies with gray wings Scoutinggpp: Trap Crops

Trap Crops/Indicator plants ▫ Susceptible varieties provide an early detection system

▫ Petunia varieties –thrips; not a reservoir for viruses

▫ Cucumbers – whiteflies; Indicator plant for thrips: ‘Carpet Blue’ Petunia concentrate release of parasitic wasps on cucumbers Scouting: When and Where Walk a section of your greenhouse/nursery once per week (3 hours/acre)

Scout least‐infested first, heavily infested areas last

Flag pest hotspots for extra treatment (biocontrol release, pesticide)

Keep records of results

Unsure?

Send samples to your county Extension office, or to the Utah Plant Pest Diagnostic Lab (UPPDL) in Logan:

utahpests.usu.edu/uppdl Comppgonents of an IPM Program • Knowledge of pest biology and behavior as well as knowledge of host plant

• Scout for insect or disease occurrence

• Knowing at what level control measures are needed (thresholds) Pest Thresholds

Economic ▫ Pest density when economic losses are reached (point when value of crop loss exceed cost of

treating) Thrips injury to leaves & flower petals Aesthetic ▫ Pest density that causes unacceptable visual injury Comppgonents of an IPM Program

• Knowledge of pest biology and behavior as well as knowledge of host plant

• Monitoring for insect or disease occurrence

• Knowing at what level control measures are needed

• Using an integrated approach to pest managgpement/prevention Integrated Control: Exclusion

Clean transplants ▫ Inspect incoming plants & materials

Keep doors closed

Screen openings ▫ Doors, ventilation openings

Barren/Clean floor surfaces ▫ Concrete, black p,plastic, weed barrier

Limit access ▫ People, “pet plants”, nonessential materials Integgprated Control: Cultural Options

• Maintain healthy, resistant plants • Choose resistant species and cultivars when available • Greenhouse environment ▫ Temperature, light/dark cycles, hidithumidity Integrated Control: Sanitation

Weed management ▫ Weed‐free inside and zone around outside perimeter Post‐harvest clean up ▫ Pressure‐wash, disinfect ▫ Sterilize soil/growth media ▫ Increase temperature to >80ºF ▫ Remove and destroy all plant materials including weeds ▫ Elim inate standing water & algae (foo d, shhlelter ) ▫ Place sticky traps to monitor pests before moving in new plants Integrated Control: Biocontrol • Periodic augmentation with predators and parasites

• Most successful when pest densities are LOW

• Must not use broad‐spectrum pesticides (pyrethroids, organophosphates‐Orthene) Examples of Pest Predators

Hippodamia Orius sp. Chrysoperla sp. Predatory thrips Aphids convergens minute pirate bug lacewing larvae lady Rhyzobius orbus Predatory thrips Soft Scales lophanthae lady beetle lady beetle Eretmocerus Encarsia formosa Chrysoperla sp. Whiteflies californicus Predatory thrips parasitoid lacewing larvae parasitoid

Hypoaspis miles Orius sp. Chrysoperla sp. Thrips Predatory thrips predatory mite minute pirate bug lacewing larvae

Hypoaspis miles Parasitic Fungus gnats predatory mite nematodes

Phytoseiulus Orius sp. Chrysoperla sp. Spider mites persimilis Predatory thrips minute pirate bug lacewing larvae predatory mite Greenhouse/Nursery INSECTS Aphids • Most common: green peach aphid and melon aphid

• Cornicles

Appgyhid Biology • Many generations per summer

• Give birth to live young sttitarting in spring

• Produce wings for dispersal when overcrowded

• Populations increase rapidly, low numbers can be tolerated Appghid Damage • Suck sap from phloem tubes in leaves and stems

• Curl leaves, produce sticky honeydew that promotes growth of black sooty mold, reduce plant vigor at high densities

• Transmit viruses ▫ green peach aphid: 100 viruses ▫ melon aphid: 44 viruses Appghid Management Biological Control –many commercially available ▫ lady ▫ lacewings ▫ parasitic wasps ▫ syrphid flies

Appghid Management • Monitoring and Thresholds ▫ chkheck under leaves (l(melon aphids ) ▫ new growing points (green peach aphid) Appghid Management

Delayed Dormant Spray (nurseries): ▫ Dormant oil + Pyrethroid (at bud break)

Spring and Summer control: ▫ reduced risk: x hard spray of water x horticultural oil x insecticidal soap x Pyrellin ((hpyrethrin+rotenone ) x azadirachtin (Azatin, Ornatin) x pyrometrozine (Endeavor)

▫ Conventional: x imidacloprid (Marathon) x Orthene x pyrethroids Fungus Gnats Bradysia and Orfelia species Fungus Gnats • Females survive for 1 week; lay up to 200 eggs on soil

• Larvae feed on fine root hairs

• Egg Æ adult in 15‐30 days Fungggus Gnat Damage • Larvae eat fine roots

• Plant wilting or poor vigor

• Adults spread viruses Fungggus Gnat Management Monitor ▫ stic ky cards ▫ potato slices Fungggus Gnat Management Nematodes – Steinernema feltiae PdtPredatory mite – HiHypoaspis miles Fungggus Gnat Management • Avoid overwatering • Eliminate algae within greenhouse • Eliminate free‐standing water

• Sppyrays ▫ Bacillus thuringiensis subsp. israelensis ▫ dozens of other products (pyrethroids, insect growth regulators, etc.) Soft Scales

• Soft scales feed in phloem, produce sticky honeydew

• Armored scales feed on mesophyll of plant cells, do not European fruit lecanium scale produce honeydew

• MlilMultiple years of scale fdifeeding can kill limbs; cause dieback

San Jose scale & injury Soft Scale Biology • Typically found on woody plants

• Adult female lays eggs under bdbody

• Hatch as nyyp,mphs, called crawlers

• Once settled, immobile

• Many generations per season

Soft Scale Management Biological control ▫ The lady beetle Rhyzobius lophanthae attacks brown soft scale and black scale. Soft Scale Management • Prune away infested plant parts

• Use sprays when crawlers are active ▫ Reduced risk: x oil x soap x insect growth regulator (Distance, Enstar, azadirachtin)

▫ Conventional: x neonicotinoid (Marathon) x acephate Armored Scales Whiteflies

Silverleaf whitefly ƒ Bemisia argentifolii ƒ Poinsettias, ornamentals Silverleaf whitefly holds wings close to body, roof-like Greenhouse whitefly ƒ Trialeurodes vaporariorum ƒ Vegetables, ornamentals

Greenhouse whitefly holds wings flat, horizontally Whiteflyygy Biology

20‐30 day life cycle ƒ 1st instar nymph – crawler

ƒ 2nd & 3rd itinstar nymphs – feeding stages; immobile

ƒ 4th instar – doesn’t feed

ƒ pupa

ƒ adult Whiteflyyg Damage

ƒ Piercing‐sucking mouthparts

ƒ Stippling on leaves

ƒ Secrete honeydew; sooty mold

ƒ Stunt plants, may cause physiological disorders

ƒ Leaves turn yy,ellow, dry, drop from plant

ƒ Transmit viruses (25+) Whiteflyyg Scouting

ƒ Monitor to detect presence – yellow sticky cards

ƒ Trap threshold = ½ per card per day when crop is young, 2 per card per day when crop approaches maturity

ƒ Inspect plants –hand lens

ƒ Leaf threshold = 10 nymphs per lfleaf Whitefly Management

Biological control Parasitic wasps Encarsia formosa for greenhouse whitefly Eretmocerus eremicus for silverleaf whitefly

Predators – Delphastus ladyy,beetle, lacewing Whiteflyyg Management: Encarsia Biocontrol

• Commercially available; parasitizes whitefly early nyypmphal stages

• 10 nymphs per leaf will sustain wasp

• 2 schemes for use: • Release once/week at rate of 2‐5 per plant for 8‐10 weeks diduring growing season

• Place cucumber plants at ends of rows to attract whiteflies; target cucumbers for wasp release

• CtCannot use bdbroad spectrum itiidinsecticides

Whitefly Insecticides

Suffocants, cuticle disruptants: Pyrethroid: • insecticidal soap • bifenthrin (Talstar) • horticultural mineral oil • cyfluthrin (Decathlon,Tempo) • fenpropathrin (Tame) IGR‐insect gggrowth regulator • lambda‐cyhalothrin (Scimitar) • kinoprene (Enstar) •fenoxycarb (Precision) Organochlorine: • pyriproxyfen (Distance) • endosulfan (Thiodan) • neem oil (Azatin) • pyridaben (Sanmite) •diflubenzuron (Adept) • novaluron (Pedastal) Miscellaneous: • flonicamid (F1785 GH) Neonicotinoids: • pymetrozine (Endeavor) • imidacloprid (Marathon) • acetamiprid (Tristar) • thiamethoxam (Flagship) Thrips Most common: western flower thrips (Frankliniella occidentalis)

Females insert 150‐300 eggs into leaves & buds

Western Flower Thrippgs Damage

Pierce cells and remove contttents ▫ tissue appears rasped, streaked, silvery

Vector of major viruses ▫ Impatiens necrotic ring spot

▫ Tomato spotted wilt Thrippgs Scouting

• Early detection is critical

• Blue sticky traps ▫ 1 trap per 1,000 sq ft ▫ Place just above canopy

• Inspect blossoms, buds, leaves

• Tap leaves & blossoms over dark sheet of paper

• Threshold: ▫ 5‐20 per trap in chrysanthemums • Indicator plants – place every 20‐30 ft ▫ ‘Carpet Blue’ and ‘Blue Madness” Petunias Thrippgs Management

• Difficult, insecticide resistance

• Biocontrol alone often is not enough

• Sanitation is key ▫ Clean stock, no debris ▫ Exclusion, screen vents ▫ 20‐ft vegetation‐free zone around house Thrips Management ‐ Biocontrol

Predatory mite, Neoseiulus cucumeris

Predatory soil mite, Hypoaspis miles

Minute pirate bug, Orius insidiosus

Minute pirate bug adult Hypoaspis miles feed on thrips pupae in the soil Thrippgs Management • Treat at 3‐5 day intervals with very good coverage

• Rotate chemicals to prevent thrips resistance ▫ Soap, Oil ▫ Mesurol ▫ Spinosad (Conserve)* ▫ Avid ▫ Pedestal (IGR) Twospppotted Spider Mite Cultural Management of Mites

• Clean up with insecticidal soap, horticultural oil or miticide

• Prevent diapause of mite in the fall • ItInterrupt nihtight with 2 hr lig ht • Keeps mites active

• Remove crop & starve mites Mite Biological Control

Predatory mite – Phytoseiulus spp. Mite Biological Control

• Phytoseiulus sold in tubes of 1,000‐ 2,000 in vermiculite or corn cob grits

• Light infestation: 10 predator mites per spider mite‐infested leaf

• Heavy infestation: 10‐100 mites per leaf

• No toxic pesticides Mite Biological Control Sppgider Mite Management

Soft Controls: ▫ pressurized stream of water ▫ horticultural oil ▫ insecticidal soap

Miticides: ▫ Acequinocyl (Shuttle) ▫ Bifenazate (Floramite) ▫ Pyridazinone (Nexter, Sanmite) ▫ Chlorfenapy r (Pylon) ▫ Etoxazole (Tetrasan) ▫ Hexythiazox (Ovation, Hexagon) Tree and Shrub Insect Borers

Attack trunks & limbs: ▫ Flatheaded beetles ▫ Roundheaded beetles Flatheaded Borers ((pBuprestidae) Flatheaded Borers ((pBuprestidae) Flatheaded Borers ((pBuprestidae) Adult flight periods for northern Utah

ƒ Pacific flatheaded borer: early May –early July ƒ Flatheaded appletree borer: late May ‐ July ƒ Bronze birch borer: late May – June ƒ Aspen borer: May‐July ƒ Poplar‐and‐Willow borer: July –Sept. ƒ Locust borer: August –Sept. ƒ Shothole borer: June and late Sept. Greenhouse/Nursery DISEASES Root‐rots • Fusarium species • PthiPythium species • Thielaviopsis basicola (black root rot)

• crop loss can be high • difficult to control ▫ proper diagnosis before implementing fungicide controls

Black root rot Root Rot Management Sanitation OiOptima l watering Minimize stress

Chemical control Pythium, Fusarium (often preventive) x Quell x Previcure Flex (vegetable) x Myypcostop (Streppytomyces spp;.; beneficial bacterium)

Black root rot (preventive, curative) x Cleary's 3336 x Terragard Botryy(tis (Gray Mold) Botryy(tis (Gray Mold)

• leaf spots • Thrives in high humidity, tightly packed plants • damping off • bud rot • Survives on living or dead • blight plant tissue

• Spreads quickly in air currents Botryygtis Management Sanitation ▫ destroy infected plant material

Manipulate greenhouse environment ▫ keep RH below 85% ▫ maintain good air circulation and plant spacing

Fungicides ▫ Kocide 101, (copper) ▫ Cleary's 3336 ▫ Domain (thiophanate‐methyl) ▫ Phyton‐27 ▫ Chipco (iprodione) ▫ Exotherm Termil ▫ Daconil 2787 (chlorothalonil Resistance Management Learn about classification of pesticides at: ItiidInsecticide RRitesistance AAtiction CCittommittee: irac‐online.org

Fungicide Resistance Action Committee: frac.info

Rotate chemical classes/modes of action within generations between generations within a season utahpests.usu.edu IPM Advisories:

Landscape Tree Fruit Small Fruit/Vegetable Turf

To sign up: utahpests.usu.edu/ipm Marion Murray IPM Project Leader Utah State University

[email protected] 435‐797‐0776