Caterpillars that can be
mistaken for Gypsy Moth

 

 

Many calls from the public to the Ministry of Forests and Range and Canadian Food Inspection Agency involve sightings of caterpillars that are not gypsy moth.  Please follow the checklist below to assist you in identifying caterpillars before you call.

Checklist:

1.  Does the caterpillar look like these (take careful note of the time of year when the stages are present)?

GM2ndinstar.JPG (7186 bytes)

Early stage (instar) - Late April to mid-June  - please note that some rare and endangered butterfly caterpillars look like very similar and should not be disturbed.  See PHOTO of Taylor's Checkerspot.  More information on rare and endangered lepidoptera associated with Garry Oak meadows can be found on the Garry Oak Ecosystem Recovery Team web site.

AsianGM.jpg (14604 bytes)

Late stage (instar) - mid-June to July

Gypsy moth caterpillars are:

  • hairy
  • not an "inchworm"
  • hatch in in early May and grow through the summer
  • late stage caterpillars are the size of your little finger
  • later stages have distinctive rows of paired red and blue dots along their backs>
  • do not form tents and leave little webbing
  • rarely feed on coniferous (evergreen) trees except when populations are high
Top

2.  Does the caterpillar look like any of these larvae?

Silver Spotted Tiger Moth

tigermoth.jpg (22176 bytes)

Click here to view a full sized photograph  

Look for:

  • a large caterpillar that is seen in the early spring into June.

  • feeding beginning in late winter/ early spring, ending in June

  • primarily feed on conifers (evergreens)

  • no spots

  • yellow hairs

  • webbing

  • are often seen in groups (gregarious feeders)

  • See example photos of damage on Douglas-fir (photos by T. Stevens):
Top

Douglas-fir Tussock Moth / Rusty Tussock Moth

dftm.jpg (36629 bytes)

Look for:

  • Hairy caterpillars with "tufts" or "pencils" on head and tail and "tussocks" on back
  • feeding on Douglas-fir (Douglas-fir tussock moth) / hardwoods and conifers (rusty tussock moth)
  • webbing
Top

Tent Caterpillar (western and northern)

Ntd3_71.jpg (53372 bytes)

tentcatepillar.jpg (28840 bytes)

Look for:

  • clumps of caterpillars in tents
  • short hairs
  • blue, orange or red spots
Top

Winter Moth

Look for:

  • hairless, green caterpillars
  • rolled leaves with caterpillars hiding in them
  • caterpillars suspended from single strands of webbing

See the Field Guide to Forest Damage in B.C. for more information on winter moth and bruce spanworm.

Top

The caterpillars depicted above are most commonly confused with gypsy moth along with the damage to tree leaves.  There are many other species of caterpillars that are found in trees that are potential hosts of gypsy moth but the descriptions provided above should verify that they are not gypsy moth.   If you still can not determine that it isn't a gypsy moth, contact your local Ministry of Forests and Range or the Canadian Food Inspection Agency (CFIA) at (250) 363-3618 (Vancouver Island) or (604) 666-2408 (Mainland/Interior).

For information on Moths Found in the Home, go to the Colorado State Extension Services site.  This site describes some common moths found in the home and is similar to situations in British Columbia where native moths may accidentally stray into homes.  
Top

Back to the Gypsy Moth Homepage

Contact Tim Ebata if you have comments on the presentation of this information.

BC Ministry of Forests, Lands & Natural Resource Operations
Resource Practices Branch
P.O. Box 9513 Stn. Prov. Gov.
Victoria, BC
V8W 9C2

Section phone: (250) 387-8739
Section fax: (250) 387-2136