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Pests

239 pests tracked across Western Washington landscapes, with identification, host plants, and management.

Data collection is ongoing. Profiles deepen as GDD emergence timing, lifecycle details, damage severity, and regional notes are verified from extension research.

GDD Activity Timeline

Updated 2026-04-03

Pest emergence mapped to growing degree days (base 32°F). Puget Sound lowlands data with indicator plant correlations.

0 1,111 GDD₃₂ now 1,800
Already active
White pine weevil 630 Bloodroot first bloom Spruce needleminer 870 Woolly apple aphid 945 Rhododendron lace bug 963 Azalea and rhododendron lace bug 963 Spruce spider mite 976 Serviceberry first bloom Boxwood psyllid 994 Serviceberry first bloom Codling moth 995 Roseslug 1,035 Hemlock scale 1,044 Viburnum leaf beetle 1,085 Deutzia first bloom Azalea Lace Bug 1,099 Deutzia first bloom Birch leafminer 1,102 Deutzia first bloom
Coming up
Balsam woolly adelgid 1,143 +32 to go Spruce budworm 1,160 +49 to go Boxwood leafminer 1,221 Crabapple first bloom Cooley spruce gall adelgid 1,424 Hawthorn first bloom Lilac borer 1,550 Hawthorn-Black locust Obliquebanded Leafroller 1,575 +464 to go

GDD₃₂ estimates from UMD IPMnet, calibrated to Kent, WA accumulation curve. Indicator plants signal approximate pest activity timing.

Showing 239 pests
Acalitus essigi
Redberry mite
Affects 5 plants
Acanthococcus azaleae
Azalea bark scale
Affects 173 plants
Aceria erinea
Walnut Blister Mite
Affects 7 plants
Acrobasis spp.
Leaf crumpler and Mineola moth
Affects 1 plant
Aculops fuchsiae
Fuchsia gall mite
Affects 1 plant
Aculus cornutus
Peach silver mite
Affects 36 plants
Aculus fockeui
Prunus rust mite
Affects 1 plant
Aculus schlechtendali
Apple rust mite
Affects 1 plant
Adelges cooleyi
Cooley spruce gall adelgid
Affects 20 plants
Adelges piceae
Balsam woolly adelgid
Affects 15 plants
Adelges tsugae
Hemlock woolly adelgid
Affects 6 plants
Agrilus anxius
Bronze birch borer
Affects 16 plants
Agrilus cuprescens
Rose stem girdler
Affects 4 plants
Aleyrodidae
Whitefly
Affects 13 plants
Altica ambiens
Alder flea beetle
Affects 12 plants
Anarsia lineatella
Peach twig borer
Affects 36 plants
Anasa tristis
Squash bug
Affects 1 plant
Andricus quercuscalifornicus
California Gallfly
Affects 50 plants
Aphididae
Aphids Pear
Affects 0 plants
Aphidoidea
Aphid
Affects 470 plants
Aphis fabae
Bean aphid
Affects 35 plants
Archips argyrospila
Fruittree leafroller
Affects 50 plants
Archips rosanus
Filbert Leafroller
Affects 2 plants
Argyresthia cupressella
Cypress tip moth
Affects 25 plants
Argyresthia spp.
Cypress tip moth and allies
Affects 20 plants
Argyrotaenia franciscana
Orange tortrix
Affects 17 plants
Asterolecanium spp.
Pit scale
Affects 50 plants
Athrips rancidella
Cotoneaster webworm
Affects 0 plants
Boisea rubrolineata
Western boxelder bug
Affects 45 plants
Brachycaudus helichrysi
Leaf curl plum aphid
Affects 36 plants
Brachycorynella asparagi
Asparagus aphid
Affects 1 plant
Brevipalpus spp.
False spider mite
Affects 5 plants
Bucculatrix ainsliella
Oak skeletonizer
Affects 50 plants
Bucculatrix albertiella
Oak Ribbed Casemaker
Affects 50 plants
Buprestidae
Flatheaded borers
Affects 1 plant
Byturus unicolor
Raspberry beetle (aka Western raspberry fruitworm)
Affects 0 plants
Cacoecimorpha pronubana
Carnation tortrix
Affects 193 plants
Cacopsylla pyricola
Pear psylla
Affects 3 plants
Caliroa cerasi
Pear slug
Affects 55 plants
Caloptilia azaleella
Azalea leafminer
Affects 135 plants
Caloptilia syringella
Lilac leafminer
Affects 26 plants
Campylomma verbasci
Campylomma bug
Affects 1 plant
Carulaspis juniperi
Juniper scale
Affects 26 plants
Cephalcia spp.
Western webspinning sawfly
Affects 16 plants
Ceratina spp.
Small carpenter bee
Affects 9 plants
Cercopidae
Spittlebug
Affects 6 plants
Chionaspis pinifoliae
Pine needle scale
Affects 78 plants
Chloridea virescens
Tobacco budworm
Affects 15 plants
Choreutis pariana
Apple-and-thorn skeletonizer
Affects 92 plants
Choristoneura freemani
Spruce budworm (Western)
Affects 15 plants
Choristoneura fumiferana
Spruce budworm
Affects 31 plants
Choristoneura rosaceana
Obliquebanded Leafroller
Affects 171 plants
Chromaphis juglandicola
Walnut Aphid
Affects 7 plants
Chrysobothris mali
Pacific flatheaded borer
Affects 36 plants
Chrysomelidae: Alticini
Flea beetle
Affects 47 plants
Cicadellidae
Leafhopper
Affects 51 plants
Cinara curvipes
Bow-legged fir aphid
Affects 15 plants
Cinara spp.
Giant conifer aphid
Affects 57 plants
Cnephasia longana
Omnivorous leaftier
Affects 2 plants
Coccoidea
Scale insect
Affects 73 plants
Coccus hesperidum
Brown soft scale
Affects 46 plants
Coleotechnites huntella
Rhododendron bud moth
Affects 132 plants
Coleotechnites piceaella
Spruce needleminer
Affects 16 plants
Colomerus vitis
Grape Erineum Mite
Affects 2 plants
Coloradia pandora
Pandora moth
Affects 53 plants
Contarinia pseudotsugae
Douglas-fir needle midge
Affects 4 plants
Contarinia quinquenotata
Daylily gall midge
Affects 1 plant
Coptodisca arbutiella
Shield Bearer
Affects 2 plants
Crambus spp.
Sod Webworm
Affects 1 plant
Crioceris asparagi
Asparagus beetle
Affects 1 plant
Cryptorhynchus lapathi
Poplar and willow borer
Affects 15 plants
Curculionidae
Weevil
Affects 2 plants
Cydia latiferreana
Filbertworm
Affects 2 plants
Cydia pomonella
Codling moth
Affects 18 plants
Cylindrocopturus furnissi
Douglas-fir twig weevil
Affects 4 plants
Cynipidae
Gall wasp
Affects 9 plants
Cynipidae
Stem Galls
Affects 0 plants
Dasineura gleditchiae
Honeylocust pod gall midge
Affects 3 plants
Dasineura oxycoccana
Blueberry gall midge
Affects 0 plants
Dasineura pyri
Pear leafcurling midge
Affects 0 plants
Dasineura rhodophaga
Rose midge
Affects 14 plants
Dendroctonus ponderosae
Mountain pine beetle
Affects 53 plants
Diabrotica undecimpunctata
Western spotted cucumber beetle
Affects 15 plants
Dialeurodes chittendeni
Rhododendron whitefly
Affects 132 plants
Diaphnocoris chlorionis
Honeylocust plant bug
Affects 3 plants
Diaspidiotus perniciosus
San Jose scale
Affects 55 plants
Dichomeris marginella
Juniper webworm
Affects 0 plants
Dioryctria spp.
Coneworm
Affects 94 plants
Diplolepis rosae
Rose galls
Affects 14 plants
Drosophila suzukii
Spotted-wing drosophila
Affects 55 plants
Dysaphis crataegi
Hawthorn aphid
Affects 15 plants
Edwardsiana rosae
Rose leafhopper
Affects 191 plants
Elatobium abietinum
Spruce aphid
Affects 16 plants
Enarmonia formosana
Cherry bark tortrix
Affects 83 plants
Endelomyia aethiops
Roseslug
Affects 14 plants
Epitrimerus pyri
Pear rust mite
Affects 0 plants
Eriophyes spp.
Blister mite
Affects 1 plant
Eriophyes tiliae
Linden gall mite
Affects 7 plants
Eriophyidae
Eriophyid mite
Affects 53 plants
Eriosoma lanigerum
Woolly apple aphid
Affects 1 plant
Eucallipterus tiliae
Linden aphid
Affects 7 plants
Euhexomyza schineri
Poplar twiggall fly
Affects 11 plants
Eulachnus agilis
Powdery pine needle aphid
Affects 42 plants
Eurytetranychus buxi
Boxwood Mite
Affects 5 plants
Fenusa pusilla
Birch leafminer
Affects 16 plants
Fenusa ulmi
Elm leafminer
Affects 8 plants
Forficula auricularia
Earwig
Affects 52 plants
Frankliniella occidentalis
Western flower thrips
Affects 46 plants
Gastropoda
Slug
Affects 7 plants
Gossyparia spuria
European elm scale
Affects 8 plants
Grapholita packardi
Cherry fruitworm
Affects 0 plants
Grapholita prunivora
Lesser appleworm
Affects 2 plants
Halyomorpha halys
Brown marmorated stink bug
Affects 85 plants
Hemiberlesia ithacae
Hemlock scale
Affects 22 plants
Hyphantria cunea
Fall webworm
Affects 155 plants
Icerya purchasi
Cottony cushion scale
Affects 132 plants
Illinoia liriodendri
Tuliptree aphid
Affects 2 plants
Lacanobia subjuncta
Lacanobia fruitworm
Affects 1 plant
Lepidoptera
Caterpillars
Affects 132 plants
Lepidosaphes ulmi
Oystershell scale
Affects 155 plants
Leucoma salicis
Satin moth
Affects 71 plants
Leucoptera laburnella
Laburnum Leafminer
Affects 1 plant
Lilioceris lilii
Lily leaf beetle
Affects 1 plant
Lithophane antennata
Green fruitworm
Affects 1 plant
Lophocampa argentata
Silverspotted tiger moth
Affects 20 plants
Lygus spp.
Lygus bug and plant bug
Affects 0 plants
Macremphytus tarsatus
Dogwood sawfly
Affects 23 plants
Macrosiphum rosae
Rose aphid
Affects 14 plants
Malacosoma californicum
Western tent caterpillar
Affects 12 plants
Malacosoma spp.
Tent caterpillar
Affects 137 plants
Marmara arbutiella
Madrone Leafminer
Affects 2 plants
Marmara spp.
Rose stem miner
Affects 9 plants
Megachile spp.
Leafcutting bee
Affects 63 plants
Megacyllene robiniae
Locust borer
Affects 2 plants
Merhynchites bicolor
Rose curculio
Affects 9 plants
Mindarus abietinus
Balsam twig aphid
Affects 15 plants
Monarthropalpus flavus
Boxwood leafminer
Affects 5 plants
Myzocallis coryli
Filbert Aphid
Affects 2 plants
Myzus cerasi
Black cherry aphid
Affects 38 plants
Nematus lipovskyi
Azalea sawfly
Affects 132 plants
Nemocestes incomptus
Woods weevil
Affects 0 plants
Neodiprion spp.
Pine sawfly
Affects 42 plants
Neophasia menapia
Pine white butterfly
Affects 42 plants
Neuroterus saltatorius
Jumping Oak Gall
Affects 50 plants
Noctuidae
Cutworm (climbing)
Affects 0 plants
Noctuidae
Cutworms and armyworms
Affects 69 plants
Nuculaspis californica
Black pineleaf scale
Affects 42 plants
Nymphalis antiopa
Spiny elm caterpillar
Affects 23 plants
Oecanthus fultoni
Snowy tree cricket
Affects 0 plants
Oligonychus ununguis
Spruce spider mite
Affects 55 plants
Oligotrophus betheli
Juniper tip midge
Affects 20 plants
Operophtera brumata
Winter moth
Affects 1 plant
Orgyia pseudotsugata
Douglas-fir tussock moth
Affects 20 plants
Otiorhynchus spp.
Root weevil
Affects 460 plants
Otiorhynchus sulcatus
Black vine weevil
Affects 1 plant
Parthenolecanium corni
European Fruit Lecanium
Affects 7 plants
Parthenolecanium spp.
Lecanium scale
Affects 277 plants
Pegomya rubivora
Cane maggot
Affects 0 plants
Pemphigus bursarius
Lettuce root aphid
Affects 11 plants
Pemphigus populitransversus
Poplar Petiole Gall Aphids
Affects 11 plants
Pennisetia marginata
Raspberry crown borer
Affects 10 plants
Pentatomidae
Stink bug
Affects 2 plants
Phenacoccus aceris
Apple Mealybug
Affects 2 plants
Phorodon humuli
Hop aphid
Affects 36 plants
Phyllocoptes gracilis
Dryberry mite
Affects 4 plants
Phyllonorycter apparella
Aspen leaf blotch miner
Affects 11 plants
Phyllonorycter blancardella
Tentiform leafminer
Affects 14 plants
Phyllonorycter elmaella
Western tentiform leafminer
Affects 1 plant
Phylloxera spp.
Oak leaf phylloxera
Affects 50 plants
Physokermes piceae
Spruce bud scale
Affects 26 plants
Phytomyza ilicis
Holly leafminer
Affects 17 plants
Phytonemus pallidus
Cyclamen mite
Affects 2 plants
Phytoptus avellanae
Filbert Bud Mite
Affects 2 plants
Phytoptus pyri
Pearleaf blister mite
Affects 12 plants
Pineus strobi
Pine bark adelgid
Affects 53 plants
Pissodes strobi
White pine weevil
Affects 69 plants
Pityophthorus juglandis
Walnut Twig Beetle
Affects 7 plants
Platycotis vittata
Oak Treehoppers
Affects 50 plants
Podosesia syringae
Lilac borer
Affects 13 plants
Prionoxystus robiniae
Carpenterworm
Affects 155 plants
Pristiphora geniculata
Mountain ash sawfly
Affects 8 plants
Proteoteras aesculana
Maple tip moth (Maple twig borer)
Affects 45 plants
Proteoteras moffatiana
Maple shoot moth
Affects 45 plants
Pseudococcus maritimus
Grape mealybug
Affects 1 plant
Psylla buxi
Boxwood psyllid
Affects 5 plants
Pulvinaria floccifera
Cottony camellia scale
Affects 31 plants
Pulvinaria innumerabilis
Cottony maple scale
Affects 45 plants
Pyrrhalta viburni
Viburnum leaf beetle
Affects 32 plants
Rabdophaga rigidae
Willow beaked-gall midge
Affects 11 plants
Rhagoletis completa
Walnut Husk Fly
Affects 7 plants
Rhagoletis indifferens
Western cherry fruit fly
Affects 1 plant
Rhagoletis pomonella
Apple maggot
Affects 14 plants
Rhopalapion longirostre
Hollyhock weevil
Affects 1 plant
Rhopobota naevana
Holly bud moth
Affects 17 plants
Rhyacionia buoliana
European pine shoot moth
Affects 53 plants
Scarabaeidae
White Grub
Affects 2 plants
Schizolachnus piniradiatae
Woolly pine needle aphid
Affects 42 plants
Schizura concinna
Redhumped caterpillar
Affects 50 plants
Scolytinae
Bark beetle
Affects 8 plants
Scolytus rugulosus
Shothole borer
Affects 42 plants
Scutigerella immaculata
Garden symphylan
Affects 1 plant
Sphenophorus spp.
Billbug
Affects 1 plant
Spilonota ocellana
Eyespotted bud moth
Affects 2 plants
Stenoptilodes antirrhina
Snapdragon plume moth
Affects 13 plants
Stephanitis pyrioides
Azalea Lace Bug
Affects 136 plants
Stephanitis rhododendri
Rhododendron lace bug
Affects 132 plants
Stephanitis spp.
Azalea and rhododendron lace bug
Affects 134 plants
Stigmaeopsis celarius
Bamboo Spider Mite
Affects 2 plants
Stomacoccus platani
Sycamore scale
Affects 4 plants
Symphyta
Sawfly
Affects 16 plants
Synanthedon bibionipennis
Strawberry crown moth
Affects 1 plant
Synanthedon exitiosa
Peachtree borer
Affects 38 plants
Synanthedon novaroensis
Pitch moth
Affects 4 plants
Synanthedon sequoiae
Sequoia pitch moth
Affects 57 plants
Syneta albida
Syneta beetle
Affects 1 plant
Tamalia coweni
Aphid (Manzanita leafgall aphid)
Affects 24 plants
Tetranychidae
Spider mite
Affects 358 plants
Tetranychus urticae
Twospotted spider mite
Affects 1 plant
Thysanoptera
Thrips
Affects 25 plants
Tingidae
Lace bug
Affects 135 plants
Tipula paludosa
European Crane Fly
Affects 6 plants
Tischeria immaculata
Ceanothus leafminer
Affects 12 plants
Tortricidae
Leafroller
Affects 97 plants
Toxoptera aurantii
Black citrus aphid
Affects 2 plants
Tuberolachnus salignus
Giant willow aphid
Affects 10 plants
Unaspis euonymi
Euonymus scale
Affects 7 plants
Various
Insect contaminants at harvest
Affects 0 plants
Various (Agromyzidae, Gracillariidae, Tenthredinidae)
Leafminer
Affects 41 plants
Various (Buprestidae, Scolytinae)
Flat Headed And Shothole Borers
Affects 5 plants
Various (Coleoptera, Lepidoptera)
Borer
Affects 29 plants
Various (Cynipidae, Cecidomyiidae, Eriophyidae, Psyllidae)
Leaf galls
Affects 57 plants
Various (Cynipidae, Cecidomyiidae, Eriophyidae)
Leaf and twig gall
Affects 50 plants
Various (Gracillariidae, Agromyzidae)
Leaf blotchminer
Affects 11 plants
Various (Lepidoptera)
Looper
Affects 0 plants
Vasates quadripedes
Maple Bladdergall Mite
Affects 45 plants
Vespula spp.
Yellowjacket
Affects 0 plants
Xanthogaleruca luteola
Elm leaf beetle
Affects 8 plants
Yponomeuta malinellus
Apple ermine moth
Affects 14 plants
Zelleria haimbachi
Pine needle sheathminer
Affects 42 plants