WEEK 3: JULY 17-24 IN THIS ISSUE...• Delay in fruit/flower production • A transmission of...
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IN THIS ISSUE: Lace Bugs: Pages 2-4 Verticillium Wilt of Trees and Shrubs: Pages 4-6 Hydrangea Anthracnose: Pages 7-8 TEST YOUR MASTER GARDENER SKILLS (Answer on page 8) Identify these white spots on a Mustard Green Leaf! WEEK 3: JULY 17-24 IMAGE FROM HELPDESK Please refer only to the current VCE Pest Management Guide: Home Grounds and Animals for pesticide recommendations. All pesticides recommended are at the risk of the user. Read and follow all label instructions for use, storage, and disposal. Remember, the pesticide label is the law.
Transcript of WEEK 3: JULY 17-24 IN THIS ISSUE...• Delay in fruit/flower production • A transmission of...
IN THIS ISSUE: LaceBugs:Pages2-4
VerticilliumWiltofTreesandShrubs:Pages4-6HydrangeaAnthracnose:Pages7-8
TEST YOUR MASTER GARDENER SKILLS (Answeronpage8)
IdentifythesewhitespotsonaMustardGreenLeaf!
WEEK 3: JULY 17-24
IMAGE FROM HELPDESK
PleasereferonlytothecurrentVCEPest
ManagementGuide:HomeGroundsandAnimalsforpesticiderecommendations.All
pesticidesrecommendedareattheriskofthe
user.Readandfollowalllabelinstructionsforuse,storage,anddisposal.
Remember,thepesticidelabelisthelaw.
LACE BUGS
IMAGE FROM UNIVERSITY OF
FLORIDA AZALEALACEBUG
Symptoms:• Yellowspotsonupperleaf
surfacesthatseemtolooklikemitedamagebutwithbiggerspots
• Severefeedingresultsingrayishblotchesorcompletelybrownleaves
• Brownvarnishtypedroppingsontheleaf’sunderside
IMAGE FROM RUTGERS UNIVERSITY OAKLACEBUGEGGS
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IMAGE FROM UNIVERSITY OF CALIFORNIA,
IRVINE SYCAMORELACEBUG
IMAGE FROM UNIVERSITY OF FLORIDA AZALEALACEBUGDAMAGE
LACE BUGS (CONT.)
Relevance:EggshatchinMayand1-2generationsoccurbythesummer’send
Knowingtheplantspecieswillhelpyouidentifythelacebugspecies.Belowisalistofcommonlacebugandtheirrespectivehostplants.ThoseboldedaretheonesmostprevalentinVirginia.
AndromedaLaceBug JapaneseAndromedaAzaleaLaceBug Azaleaandmountainlaurel
RhododendronLaceBug RhododendronandmountainlaurelAlderLaceBug Alder,hazel,elm,birch,andcrabapple
BrasswoodLaceBug BrasswoodandlindenBirchLaceBug Yellowbirch,whitebirch,beech,willow,mountainash,mapleandeastern
hophornbeamBuckeyelacebug BuckeyeElmlacebug Americanelm
Hackberrylacebug HackberryHawthornlacebug Hawthorn,quince,pyrancantha,cotoneaster,andserviceberry
Oaklacebug OakSycamorelacebug SycamoreandLondonplanetreeWalnutlacebug Blackwalnut,butternut,andlinden
Willowandpoplarlacebug Willow,balsampopular,bigtoothaspen,andquakingaspenWillowlacebug Willow
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Description:adultsare1/8”to1/4”inchlongwithanetlikepatternonthewings.Inaddition,theirwingsaredottedwithbrownandblack.Lacebugeggs
areelongatedandcylindricalshapes.
DamagetoPlants:Lacebugfeedingisdirectlyharmfultoplants
MoreResourcesforLaceBugControl
VCEPestManagementGuide:HomeGroundsandAnimalsVCEExtension:LaceBugsUMDExtension:LaceBugs
PennStateExtension:LaceBugsonBroad-LeavedEvergreenOrnamentalPlantsPennStateExtension:LaceBugonDeciduousWoodyOrnamentalPlants
VERTICELLIUM WILT OF TREES AND SHRUBS Relevance:SymptomsofdiseasearemoreapttoappearinJulyandAugust
Why:Causedbysoil-bornefungi,Verticilliumalbo-atrumandVerticilliumdahliae.Thefungusiscommoninmanysoilsbutpreferscertainhoststhatincludetrees,shrubsandevenvegetablesespeciallythetomatoplant.BelowisatableofcommontreesandshrubssusceptibletoVerticilliumWilt.
Ash Maple Honeysuckle RussianOlive SmoketreeAzalea Elm Linden Plum SpireaJapaneseBarberry
Dogwood BlackLocust Redbud Sumac
Catalpa Elder Magnolia Rose ViburnumCherry,otherstonefruits
CurrantandGooseberry
KentuckyCoffeeTree
Oak,pineandred(rare)
Weigela
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BestControlMethods:• Monitorplantsregularlyinspringforlacebugsigns
• PlantAzaleaandRhododendroninashadyareatoavoidheavylacebugpopulations
DamagetoPlants:Seriousdiseasesincethefungispreadsinternallyorsystematicallywithintheplantandcanleadtoplantdeath
Symptoms
• Small,yellowfoliage• Leafscorch(marginalbrowning)• Slowgrowth• Abnormallyheavyseedcrops• Oftenonebranch/side/sectionis
affected• Someexhibitelongate,dead
areasofbarkondiseasedbranches/trunks
• Diebackofshootsandbranches• Leafcurling,drying• Abnormalredoryellowcolorof
leavesorinareasbetweenleafveins,partialdefoliation,wiltingandbranchdieback
• Inwiltingbranches,therearediscoloredstreaksinbark
a) Greentoblackinmaplesb) Browninelmsc) Browntoblackinblacklocust
andothertrees
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IMAGEFROMPURDUEUNIVERSITYVERTICELLIUMONMAPLE
IMAGEFROMUMASSAMHERSTVERTICELLIUMONGREENASH
BestControlMethods• Donotreplantsusceptiblespecieswhereaspecimenwaskilledby
VerticilliumWilt• Pruneoutaffectedlimbs;waterandfertilizetomaintaintreevigor• NeverusewoodchipstakenfromaVerticilliuminfectedtreeasmulchor
pottingmedium• Topreventspread,disinfecttools
MoreResourcesforVerticilliumWiltControl
UniversityofMinnesotaExtension:VerticilliumwiltoftreesandshrubsPennStateExtension:VerticilliumWiltofWoodyOrnamentals
MissouriBotanicalGarden:VerticilliumWilt
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IMAGE FROM MICHIGAN STATE
UNIVERSITY VerticilliumonNorway
maplewithgreendiscoloration
HYDRANGEA ANTHRACNOSE
• Circularorirregularlyshapedbrownspots
• Spotsturnfromlightbrowntotan
• Spotshaveabull’seyeappearance
• Spotsbecomeangularoncetheyhavereachedlargeleafveins
Relevance:Hydrangeaanthracnosefavorshotandwetconditions.
Why:CausedbythefungusCollectotricbumgloeosporioides,whichcanattackboththeleavesandbloomsofthehydrangea.Heavilyfertilizedhydrangeas
maybemostsusceptibletoattackbyC.gloeosporioides.
Symptoms:
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IMAGES FROM THE MASTER GARDERNER COORDINATOR ANTHRACNOSEONHYDRANGEAS
TEST YOUR MASTER GARDENER SKILLS
Answer:ThewhitespotsareAphideggsandlarvae!
Aphidsaresoft-bodiedinsectsthataremainlygreenorblack.However,therearehundredsofspeciesandthese“plantlice”canalsobelavender,gray,brown,pink,redoryellow.Acommoncharacteristicbetweenallspeciesisthepresenceoftwotubes,calledcornicles,onthebackendsoftheirbodies.Aphidsfeedinclustersandgenerallyprefertofeedonnew,succulentshootsorleaves.Lightinfestationsareusuallyharmlesstotheplantsbutheavyinfestationscanresultin:
• Leafcurl• Wilting• Stuntingofshootgrowth• Delayinfruit/flowerproduction
• Atransmissionofpathogenstoplants
• Honeydew(aphidexcrement)buildupwhichcanleadtosootymold
BestControlMethods:Collectanddiscarddiseasedbloomsandleaves
Takingcuttingsfromsymptom-freeplantswillpreventspreadLimityourtimegardeninginwetconditionssincesporesprimarilyspread
throughsplashingwater
MoreResourcesforHydrangeaAnthracnose:AlabamaCooperativeExtensionSystem:DiseasesofHydrangea
TennesseeStateUniversity:FoliarDiseasesofHydrangeasPestManagementGuide:HomeGroundsandAnimals
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BestControlMethods:Maintainplantvigor
PlantflowersthatattractbeneficialpredatorslikeLadyBeetles,lacewings,damselbugs,flowerflymaggots,certainparasiticwasps,andbirds
MoreResourcesforControllingAphids:VCEExtension:Aphids
OregonStateExtension:HowtocontrolaphidswithlesstoxicmethodsPermacultureResearchInstitute:PlantsthatAttractBeneficialInsects
PestManagementGuide:HomeGroundsandAnimals
THANK YOU FOR READING!
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