Discovering and Exploring the Leaf-feeding Insects in Our Region

Pacific Northwest (PNW) Defoliators

Species FAQs

 

Status
NATIVE
ESTABLISHED
NEWLY INTRODUCED
Here are some of the basic facts on the most common defoliators found in the Pacific Northwest. The color code shows their status as a native, long established or newly introduced species. The maps show where surveys have recorded their presence. Click image for an enlargement.
Ancylis apicana  
Ancylis apicana larva
Ancylis apicana
Ancylis apicana spread
 
A leaf-folder with an intriguing leaf-stitching behavior, where larvae connect silk to two sides of a leaf (or two different leaves) and pull them together into the folded position. Although its range is identified as across the northern United States and adjacent Canada, it was only identified from Washington in 2009.
Apple-and-thorn skeletonizer, Choreutis pariana  
Apple thorn moth
Apple-thorn skeletonizer
A widespread native (or very long established exotic) defoliator moth that feeds on apple, cherry, birch, hawthorne, willow, and mountain ash. Multiple generations per year create distinctive skeletonized leaves by eating only the surface of leaves and webbing leaves into a cup shape. >> More OSU info
Apple ermine moth, Yponomeuta malinellus appletortrix_map
Apple ermine moth larva
Apple ermine moth
Apple ermine moth
An exotic defoliator with larvae that feed as a group inside small web shelters (tents) on apple trees. First found in the U.S. in Whatcom County in 1985, it has rapidly spread throughout Washington State and into Oregon (see map). Larvae skeletonize and consume leaves in fist-sized tents, creating a series of tents along branches as leaves are consumed. Severe defoliation (seen in 1980's) has been controlled by an imported parasitoid. >> More WSU info
Apple leafcurling midge, Dasineura mali
Apple midge larva
Apple midge
An exotic fly with several generations per season of tiny larvae that cause apple leaves to curl inward as they develop, stunting growth. Also found in New England, the exotic species was first found in Washington in 1991, in Whatcom County.
>> More WSU info
Apple skeletonizer, Swammerdamia pyrella Apple skeletonizer map
Apple skeletonizer larva
Apple skeletonizer
Apple skeletonizer
An exotic defoliator moth with distinctive larvae that skeletonize apple and hawthorn leaves. First found in Whatcom county in 1994, it also occurs in other Western Washington counties, but is relatively rare.
Apple Tortrix, Archips fuscocupreanus appletortrix_map
Apple tortrix larva
apple tortrix live
Apple tortrix adult
An exotic leaf-rolling defoliator, first found in North America in Western Washington in 1995, also recently found in New England. One of the most abundant defoliators in the Puget Sound area, larvae from one generation per year feed on a wide variety of deciduous trees and shrubs in spring. >> More info
Apricot moth, Ditula angustiorana  
Apricot moth
Apricot moth
Apricot moth
An exotic leafroller, long established in several areas of North America, rolls and feeds on fruit tree leaves and also some conifer needles. One generation per year of larvae are not common on fruit trees, but are found throughout Western Washington. >> More info
Barred fruit tree tortrix, Pandemis cerasana Barred  fruit tree tortrix
Barred fruit tree tortrix
Barred fruit tree tortrix
A recently introduced exotic defoliator which occurs in N. America only in the Puget Sound and British Columbia region. Has a wide host range from ornamentals to fruit trees. Has one to two generations per year and overwinters as larvae.
>> More info
Carnation tortrix, Cacoecimorpha pronubana Carnation tortrix map
Carnation tortrix moth
Carnation tortrix
An exotic defoliator which has been in the region for several decades. Occurs in N. America from Oregon north to British Columbia. Has a wide host range among ornamentals. One generation per year.
Cherry blossom moth, Argyresthia pruniella Dowload report
Cherry blossom moth
Cherry blossom moth
Cherry blossom moth
A European import, detected in British Columbia in 2009 and Whatcom County in 2011. The tiny adults fly in late summer and lay eggs on the bark of cherry trees. Larvae are active in early spring, when they feed on the ovaries of developing fruit.
Cherry ermine moth, Yponomeuta padellus
Cherry ermine moth
Cherry ermine moth
Cherry ermine moth

A recently introduced and uncommon exotic defoliator with larvae that feed as a group inside small web shelters (tents) on prunus and hawthorne. Found in N. American only from the Willamette Valley north to western British Columbia.

Dark fruit tree tortrix, Pandemis heparana Dark fruit tree tortrix map
Dark fruit tree tortrix
Dark fruit tree tortrix
Dark fruit tree tortrix
A long established exotic defoliator. One of the more common leafrollers of fruit trees and some ornamentals Found in N. America only in the Puget Sound region. Two generations per year and overwinters as larvae.
Epinotia albangulana  
Epinotia albangulana larva
Epinotia albangulana
Epinotia albangulana
A native and common defoliator that feeds on the catkins of alder. Found from California to British Columbia and Idaho. One generation per year. >> More Info
European fruit tree tortrix moth, Archips podana  
European fruit tree tortrix moth larva
European fruit tree tortrix
European fruit tree tortrix
Exotic defoliator introduced in the mid/late 1900s. While a serious economic pest of fruit trees and ornamentals in Europe, its distribution in N. America has been restricted to Whatcom Co. and British Columbia. Unlike all other Archips has a partial second generation each year. >> More info
European leafroller, Archips rosanus  
European leafroller larva
European leafroller
European leafroller
A long established and widespread exotic defoliator in the Puget Sound region. The most abundant and common leafroller on fruit trees, ornamentals and native species. One generation per year, overwinters as eggs.
Eye-spotted bud moth, Spilonota ocellana  
Eye-spotted bud moth larva
Eye-spotted bud moth
Eye-spotted budmoth
A long established exotic defoliator that in now widespread in N. America. Feeds on many fruit and ornamentals. One generation per year and overwinters as larvae.
Fall webworm, Hyphantria cunea  
Fall webworm tent
Fall web worm larva
Native web-making species with a cyclical population. During outbreak years commonly seen with predominant tents in wide variety of fruit and deciduous trees and ornamentals. One generation per year.
Garden rose tortrix, Acleris variegana  
garden rose tortrix larva
Garden rose tortrix
Garden rose tortrix
A long established introduced exotic. A less common leafroller that feeds on many fruit trees and ornamentals. One generation per year, overwinters in egg stage.
Golden leafroller, Acleris holmiana Golden leafroller map
Golden leafroller larva
Golden leafroller
Golden leafroller
Recently introduced exotic. Abundant on many fruit trees and ornamentals in the Puget Sound region. The small golden larva fold leaf edges but never damage fruit.
Green alder sawfly, Monsoma pulveratum Green Alder Sawfly map Download Map
Green alder sawfly larva
Monsoma pulveratum
Monsoma pulveratum
European exotic established in eastern Canada since the early 1990s, detected in Alaska in 2009 and Washington in 2010. Now found in ten western WA counties, from Clark to Whatcom. Larvae feed voraciously on alders in spring and early summer, and have caused severe defoliation of Alnus tenuifolia in Alaksa. Think you have Monsoma pulveratum? Use this ID sheet to see.
Green pug moth, Pasiphila rectangulata Green budworm map
Green pugmoth larva
Green pugmoth
An introduced exotic in the NW and the East Coast.
Green budworm, Hedya nubiferana  
Green budworm larva
Green budmoth
Green budworm
An introduced exotic in the NW and the East Coast where it is a less common leafroller on fruit trees and ornamentals. One generation per year, overwinters as larvae.
Lesser budmoth, Recurvaria nanella Lesser budmoth
Lesser budmoth larva
Lesser budmoth
Lesser budmoth
A long established exotic defoliator that in now widespread in N. America. Feed in webbed-up leaves at branch tips of many fruit and ornamentals. One generation per year and overwinters as larvae.
Lilac leaf miner, Caloptilia syringella  
Lilac leaf miner defoliation
Long established exotic widespread in N. America. Larvae create blotched mines only on lilacs.
Mountain ash sawfly, Pristiphora geniculata  
Mountain Ash Sawfly Larva
An introduced exotic that occurs in northeastern North America, discovered in Snohomish County in 2009. Larvae consume new growth on mountain ash, causing extensive defoliation. >> More Info
Oak skeletonizer, Carcina quercana Oak skeletonizer map
Oak skeletonizer larva
Oak skeletonizer
Oak skeletonizer
A recently introduced exotic that occurs only in N. America in British Columbia and western Washington. Have been observed seriously defoliating ornamental prunus in Whatcom and King Co. One generation per year.
Oblique-banded leafroller, Choristoneura rosaceana  
Oblique-bande leafroller larva
Oblique-banded leafroller
Oblique-banded leafroller
Native defoliator. The most common leafroller on fruit trees and ornamentals in eastern and western Washington. Two generations per year and overwinters as larvae.
Orange tortrix, Argyrotaenia franciscana  
Orange tortrix larva
Orange tortrix
Orange tortrix
Native species common at times on a large list of fruit trees, berries and ornamentals. Two generations per year and overwinters as larvae.
Oreana unicolorella  
Oreana unicolorella larva
Oreana
Oreana unicolorella is found across the northern United States and southeastern Canada. This leaf roller has a wide host range, including apple, birch, elm, willow, and maple.
Silver-spotted tiger moth, Lophocampa argentata  
Silver spotted tiger moth web
The most common native web-making species in conifers in the NW region. Larva overwinter in small tents, which grow to visibility in spring.
Tent caterpillar, Malacosoma californicum pluviale  
Tent caterpillar larva
One of several native tent-making species in the NW. Various species feed on fruit trees, ornamentals and native trees. Most feed as a group in tents. One generation per year, overwinter in egg stage.
Winter moth, Opherophtera brumata  
Winter moth larva
Winter moth
European exotic established in the NW since the 1970s. Occurs from the Willamette Valley to western British Columbia and on the East Coast. Larvae are the earliest feeders in spring of wide range of fruit tree, ornamentals and berry bushes. Gets its name from the adult flight early in Oct/Dec. One generation per year.
 

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