University of Maryland Extension

Pest Predictive Calendar-Landscape/Nursery

The Pest Predictive Calendar is a monitoring tool to assist in predicting when susceptible life stage(s) (stage you want to target for control measures) of pest insects are active by using plant phenological indicators (PPI) and growing degree days (GDD). This tool will lead to improved timing of management tactics and more effective pest management.

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Phenological sequence of plant flowering and insect events with their associated GDD in Maryland. For more information go to: How to Use the Pest Predictive Calendar and Getting and Using Growing Degree Days.
Plant/Pest Common Name
Taxonomic Name
Phenological Event
Persian speedwellVeronica persicafirst bloom16
Corneliancherry dogwoodCornus masfirst bloom22   
Red mapleAcer rubrumfirst bloom34
Border forsythiaForsythia x intermediafirst bloom35
Euonymus leaf-notcher caterpillarPryeria sinicaegg hatch37
Red mapleAcer rubrumfull bloom42
Callery pear (MD Tier 2 Invasive Plant)Pyrus calleryanafirst bloom50
Eastern tent caterpillarMalacosoma americanumegg hatch51
Purple deadnettleLamium purpureumfirst bloom52
Border forsythiaForsythia x intermediafull bloom53
Saucer magnoliaMagnolia x soulangeanafirst bloom59
Star magnoliaMagnolia stellatafirst bloom89
Flowering quinceChaenomeles speciosafirst bloom103
Bridal wreath spireaSpirea x vanhoutteifirst bloom104
Callery pear (MD Tier 2 Invasive Plant)Pyrus calleryanafull bloom105
Koreanspice viburnumViburnum carlesiiFirst bloom117
Sargent's cherryPrunus sargentiifirst bloom121
SassafrasSassafras albidumfirst bloom122
Bridal wreath spireaSpirea x vanhoutteifull bloom123
Eastern redbudCercis canadensisfirst bloom137
SassafrasSassafras albidumfull bloom138
Sargent's cherryPrunus sargentiifull bloom140
Double weeping higan cherryPrunus subhirtella 'Pendula Plena Rosa'first bloom142
Cherry laurelPrunus laurocerasusfirst bloom144
Koreanspice viburnumViburnum carlesiifull bloom149
Red buckeyeAesculus paviafirst bloom154
Canadian serviceberryAmelanchier canadensisfirst bloom154
Eastern redbudCercis candensisfull bloom156
Fernald’s shadbushAmelanchier fernaldiifull bloom163
Woolly elm aphidEriosoma americanaegg hatch163
Nantucket serviceberryAmelanchier nantucketensisfull bloom171
Spiny witchhazel gall aphidHamamelistes spinosusadult/nymph171
Serviceberry 'Autumn Brilliance'Amelanchier x grandiflorafirst bloom179
Double weeping higan cherryPrunus subhirtella 'Pendula Plena Rosa'full bloom195
Mountain pierisPieris floribundafull bloom197
White enkianthusEnkianthus perulatus 'JL Pennock'full bloom204
Slender deutziaDeutzia gracilus Nikkofirst bloom211
Roseslug sawflyEndelomyia aethiopsegg hatch/early instar230
Serviceberry 'Autumn Brilliance'Amelanchier x grandiflorafull bloom235
Boxwood leafminerMonarthropalpusi flavusadult emergence249
Crabapple 'Adirondack'Malus 'Adirondack'first bloom260
Dwarf azaleaRhododendron atlanticumfirst bloom260
MayapplePodophyllum peltatumfirst bloom264
Spruce spider miteOligonychus ununguisadult/nymph276    
Dogwood 'Appalachian Spring'Cornus florida 'Appalachian Spring'first bloom281
Andromeda lace bugStephanitis takeyaiegg hatch281
Azalea lace bugStephanitis pyrioidesegg hatch (1st gen)281
Pine needle scaleChionaspis pinifoliaeegg hatch/crawler (1st gen)307

Sheep laurelKalmia angustifolia 'Royal Dwarf'first bloom314
Red buckeyeAesculus paviafull bloom324
Spirea aphidAphis spiraecolaadult/nymph326
Hemlock woolly adelgidAdelges tsugaeegg hatch (1st gen)300
Lilac borerPodosesia syringaeadult emergence350
Black locustRobinia pseudoacaciafirst bloom357

Dogwood 'Appalachian Spring'

Cornus florida 'Appalachian Spring'full bloom358

Hawthorn 'Winter King'

Crataegus viridis 'Winter King'first bloom358
Pinxterbloom azaleaRhododendron periclymenoidesfull bloom360
Crabapple 'Adirondack'Malus 'Adirondack'full bloom379
Black locustRobinia pseudoacaciafull bloom386
Red horsechestnutAesculus x carnea 'Ft. McNair'first bloom389
Basswood lace bugGargaphia tiliaeadult/nymph415
Emerald ash borerAgrilus planipennisadult emergence421 
Blue false indigoBaptisia australis 'Purple Smoke'first bloom431
Fourlined plant bugPoecilocapsus lineatusegg hatch/early instar435
Lesser peachtree borerSynanthedon pictipesadult emergence (1st gen)468
Maskell scaleLepidosaphes pallidaegg hatch/crawler (1st gen)470
Thornless honeylocust 'Skyline'

Gleditsia triacanthos f. inermis 'Skycole' SKYLINE

first bloom472
Japanese snowbell

Styrax japonicus

first bloom477
Thornless honeylocust 'Skyline'

Gleditsia triacanthos f. inermis 'Skycole' SKYLINE

full bloom478
Oystershell scale

Lepidosaphes ulmi

egg hatch/crawler (1st gen)486


Liriodendron tulipifera

first bloom490
Virginia spiderwortTradescantia virginianafirst bloom494
Gypsy mothLymantria disparegg hatch
TuliptreeLiriodendron tulipiferafull bloom509
Red horsechestnutAesculus x carnea 'Ft. McNair'full bloom511
White prunicola scalePsedaulacaspis prunicolaegg hatch/crawler (1st gen)513

Hawthorn 'Winter King'Crataegus viridis 'Winter King'full bloom515
Cottony camellia/Taxus scalePulvinaria flocciferaegg hatch520

Euonymus scaleUnaspis euonymiegg hatch/crawler (1st gen)522
American smoketreeCotinus obovatusfull bloom575
Common ninebarkPhysocarpus opulifolius ‘Luteus’full bloom583
Yellow flag iris (Maryland Tier 1 invasive plant)Iris pseudacorusfirst bloom587 
Clematis 'Westerplatte'Clematis ‘Westerplatte’full bloom589
American yellowwoodCladrastis kentukeafirst bloom600
BagwormThyridopteryx ephemeraeformisegg hatch602
American yellowwoodCladrastis kentukeafull bloom627
Japanese snowbellStyrax japonicusfull bloom677
Virginia spiderwortTradescantia virginianafull bloom692
Juniper scaleCarulaspis juniperiegg hatch694

Calico scaleEulecanium cerasorumegg hatch/crawler714
Oak leacanium scaleParthenolecanium quercifexegg hatch/crawler789
Japanese maple scaleLopholeucaspis japonicaegg hatch/crawler (1st gen)829 
European elm scaleGossyparia surplusegg hatch/crawler831
SmoketreeCotinus coggygria full bloom866
European fruit lecanium scaleParthenolecanium corniegg hatch/crawler904
Japanese stewartiaStewartia pseudocameliafirst bloom908
Cottony maple scalePulvinaria innumerabilisegg hatch/crawler932
Smooth witherod/Possumhaw viburnumViburnum nudum ‘Winterthur’full bloom1002
Mimosa WebwormHomadaula anisocentraegg hatch/crawler (1st gen)1002
Japanese stewartiaStewartia pseudocameliafull bloom1027
Japanese beetlePopillia japonicaadult emergence1056
Cryptomeria scaleAspidiotus cryptomeriaeegg hatch/crawler (1st gen)1101
Fletcher scaleParthenolecanium fletcheriegg hatch/crawler1105
Bottlebrush buckeyeAesculus parviflorafirst bloom1137
Indian wax scaleCeraplastes ceriferusegg hatch/crawler1145
Oriental beetleAnomala orientalisadult emergence1147
Bottlebrush buckeyeAesculus parviflorafull bloom1200
MimosaAlbizia julibrissinfirst bloom1215
Butterfly weedAsclepias tuberosafirst bloom1216
Fall webwormHyphantria cuneaegg hatch (1st gen)1319
MimosaAlbizia julibrissinfull bloom1330
BeebalmMonarda sppfirst bloom1380
GoldenraintreeKoelreuteria paniculatafirst bloom1393
Satin blue Rose-of-SharonHibiscus syriacus 'Satin Blue'first bloom1492
Swamp milkweedAsclepias incarnatafirst bloom1510
Pine needle scaleChionaspis pinifoliaeegg hatch/crawler (2nd gen)1537
Green June beetleCotinus nitidaadult emergence1539
GoldenraintreeKoelreuteria paniculatafull bloom1597
White prunicola scalePsedaulacaspis prunicolaegg hatch/crawler (2nd gen)1637

Satin blue Rose-of-SharonHibiscus syriacus 'Satin Blue'full bloom1742
Obscure scaleMelanaspis obscuraegg hatch/crawler1774
Orangestriped oakwormAnisota senatoriaegg hatch (early instar)1917
Maskell scaleLepidosaphes pallidaegg hatch/crawler (2nd gen)2035
Regent pagodatreeStyphnolobrium japonicumfirst bloom2111
Euonymus scaleUnaspis euonymiegg hatch/crawler (2nd gen)2235 
Crapemyrtle 'Natchez'Lagerstroemia x 'Natchez'first bloom2251
Regent pagodatreeStyphnolobrium japonicumfull bloom2330
Crimsoneyed rosemallowHibiscus moscheutosfirst bloom2464
Hollow joe pye weedEutrochium fistulosum
first bloom2494
Japanese maple scaleLopholeucaspis japonicaegg hatch/crawler (2nd gen)2508
Natchez crape myrtleLagerstroemia x 'Natchez'full bloom2617
Crimsoneyed rosemallowHibiscus moscheutosfull bloom2704
Seven-son flowerHeptacodium miconioidesfirst bloom2770
Fall webwormHyphantria cuneaegg hatch/crawler (2nd gen)2793
Seven-son flowerHeptacodium miconioidesfull bloom3072
White prunicola scalePsedaulacaspis prunicolaegg hatch/crawler (3rd gen)3270

Banded ash clearwing borerPodosesia aureocinctaadult emergence3357
Tuliptree scaleToumeyella liriodendriegg hatch/crawler3519
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