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ADozenWaystoPreventPestProblemsinYourOrganicGardenUsingtheIPMApproach

MaryLouiseFlint,Ph.D.ExtensionEntomologistEmerita

UCDavis

Yourgardenisanecosystem•  Manageittofavorthegrowthofdesiredplants

andpreventpestproblems.•  Youmustplanahead.Thebestwaystobeat

pestsarepreventive.•  Oncepestproblemsgetoutofcontrol,they

maynotbemanageableoryouwillneedtousesuppressivetoolsthatmayhaveotherunwantedimpacts.

•  Identifyyourpests.Recognizethebeneficialsinyourgardenecosystem.

•  Choosemethodsthatareappropriateforyourpestsandgrowingsituationanduseanintegratedapproach.

•  Hereare12waysyoucanpreventproblems.

1.Ensurethattheplantingareaispest-freebeforeyouplantortreesstartgrowing

•  Removeoldcropdebris•  Removeweedsandtheirpropagules

•  Eliminatepestrefuges•  Ifcertainsoilbornepathogens,nematodesorperennialweedsarepresent,solarizationorrotationmaybeappropriate

Squashbug

Brownrotonapricot

Snailshiding

Solarizationcanreducecertainsoilborneweeds,pathogensandnematodes.

Fusariumwiltinbeans Rootknotnematodeinlettuce

cheeseweed

2.PlantSmart:Whereavailable,choose:

•  Resistantcultivarsorrootstocks

•  Asunnysitewithoutahistoryofpestproblems

•  Plantingtimesthatavoidpests(transplantifnecessary)

•  Locationsawayfromuncultivatedareas

•  Timelyharvest

Damping-offofseedlings

Powderymildewonmelons

Pestsmaymoveinfromnearbyuncultivatedorweedyareas

Curlytopvirusonpeppers—leafhoppervector

Codlingmoth

Spottedcucumberbeetle cutworm

Fieldcricket

AlsoWeeds!

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3.EncourageNaturalEnemiesofPests

•  Learntorecognizethem

•  Don’tkillthemwithpesticides

•  Floweringplantsprovidepollenandnectarthatallowthemtolivelongerandlaymoreeggs

Predatorssuchasladybeetles

Parasitessuchasthisaphid-killingwasp

Ceanothusandalyssumprovidepollenandnectarfornaturalenemies

Greenlacewinglarva,adultandeggonstalk

Asianmulticoloredladybeetleadultlarvaandpupa

Ladybeetleeggs

Syrphidflyadultandlarva

Afewcommonpredators

What is Biological Control?

Parasites (technically Parasitoids)

•  Most are wasps or flies

•  Often smaller than their host

•  Kills only one host individual

•  Develop inside or outside of the host

9 Aphid parasite life cycle

Wasp laying egg in aphid host

Caterpillar parasitoid 4.Consideryourirrigation

system•  Overwateringpromotesrootandcrowndiseases

•  Wetwateronfoliagecanfavordevelopmentoffoliardiseases

•  Dripirrigationdirectswaterwhereyouneedit,reducesweed,diseaseandsnailandslugproblems

Phytophthoraonbrusselsprouts

5.Rowcoversorcapsprotectsmallplantsfromseedlingpests.

Fleabeetles

Cabbageandseedmaggots Thrips Aphids

Fencingandgopherbasketsprotectagainstsomevertebratepests.

Barriers

Copperbarriersrepelsnailsandslugs

Birdnetting

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6.Keepplantswellventilatedandfruitofftheground

pillbugs GraymoldontomatoBunchrotongrapes

Graymoldonstrawberry

trellis

7.Mulch•  Mulchessuppressweeds,keepdowndust,moderatetemperatures,preservemoisture

•  Dustencourageswhitefliesandspidermitesandsuppressesbeneficials

•  Reflectivemulchesrepelvirusvectorsincludingaphids,thripsandwhiteflies

•  Mulchescanharborsomepests,somonitorthem

Strawmulch

Reflectivemulch

WhiteflyadultsandnymphsEarwigsandotherpestsmayhideinmulch

8.Don’taddtoomuchorganicmatter

•  Mostgardensdon’tneedregularincorporationoforganicmatter.

•  Moderateamountgoodtoimprovedrainageandaeration.

•  Toomuchleadtoproblemswithsymphylans,springtails,cutworms,wireworms,greenfruitbeetlegrubs,nutrientdeficienciesandmore.

springtails

Wirewormanddamage

cutworm

Greenfruitbeetlegrubs

9.Regularlymonitoryourgarden

•  Learntoidentifypests,theirdamageandbeneficials

•  UseUniversityofCaliforniaresourcesforhelpwww.ipm.ucanr.edu

•  Otherexpertsinyourofficecanhelp•  Appropriatechoiceofmanagementmethodsrequiresyouproperlyidentifypests

•  ManyplantpathogensrequirealabtesttoID

Resources:Orderfromwww.anrcatalog.com

UCIPMWebSitewww.ipm.ucanr.edu

10.HandpickingandTraps

•  Identifyinsecteggsanddestroythembeforetheyhatch.

•  Pickoffcaterpillars,stinkbugs,squashbugsandotherpests.

•  Somediseasescanbereducedbypruningoffdiseasedleavesorbranches.

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Ladybeetle Squashbug Stinkbug

AssassinbugOmnivorousleafroller Beetarmyworm

Greenlacewing Tomatofruitworm/looper

InsectEggsPickoffthebad.Protectthegood.

Notethataphidsusuallydon’thaveeggs

PickofforPruneOut

Fireblight Squashbug Stinkbugs

Aphidcurledleaves HornwormLooper

Traps

Boardtrapforsnailsandslugs.Smallerboardtrapscanbeusedforsquashbugs.

PheromonetrapforLepidopteraUsemostlyformonitoring

Gophertrap

Yellowstickytrap

Rollednewspaperforearwigs

11.ConsiderSpraysonlyasalastresort

•  Water•  Insecticidalsoaps•  Oils•  Food-basedvolatileoils•  Microbials•  Botanicals•  Ironphosphate•  Spinosad•  Sulfurandcopperfungicides

Usepesticides,includingtheseorganiconesonlywhennecessaryandapplytheminawaythatensurestheireffectivenessandsafetytopeople,beneficialsandtheenvironment.

Waterspray

12.CustomizeandRefineyoursystem

•  IntegrateseveralmanagementtoolsintoanIPMprogramforyoursituation.

•  Getcreative.Experiment.Keepnotes.Research.

•  Learn.

Resources:Orderfromwww.anrcatalog.com

UCIPMWebSitewww.ipm.ucanr.edu

AlsocontactyourlocalUCMasterGardeners