Discovering and Exploring the Leaf-feeding Insects in Our Region

Pacific Northwest (PNW) Defoliators

What's Eating My Trees and Shrubs
Identify Defoliators on: Alder Trees

Species listed here are the most common defoliators of alder trees in the Puget Sound region. Species are listed from most widespread and abundant to least common and or of limited distribution (2007 data).
Type of Defoliation Species When Where Status
Leaf -rollers
Leaf roller damage
Leaf roller
Partial roll
European leaf-roller European leafroller
Archips rosanus
April-
June
Wide
spread
Exotic,
here
since
1960's
Apple tortix Apple Tortix
Archips fuscocupreanus
May
Puget
Sound region
Exotic,
here
since
1990's
Oblique-banded leafroller Oblique-banded leafroller
Choristoneura rosaceana
April-
June
Wide
spread
Native
Epinitia albangulana Epinotia albangulana
April-
June

Calif. to
BC, and Idaho

Native
 

Shothole
green alder sawfly damage
Species When Where Status
green alder sawfly green alder sawfly
Monsoma pulveratum
April-
??
W. WA, OR and BC
Exotic, since ~1995
green alder sawfly  

Tent makers
tent makers
Species When Where Status
Tent caterpillar Tent caterpillar
Malacosoma constrictum
April-
June
Wide
spread
Native
Fall webworm Fall webworm
Hyphantria cunea
July-
Sept or
Oct.
Wide
spread
Native
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