western tent caterpillar moth

(Malacosoma californicum)

 

No Image Available

  Hodges #

7702

 
 
Conservation Status
  IUCN Red List

not listed

     
  NatureServe

N5 - Secure

     
  Minnesota

not listed

     
           
 
Description
 
 

Western tent caterpillar moth is common in western United States and western Canada, less common from Manitoba to Quebec. Isolated populations have been found in northern Minnesota, New Hampshire, and New York.

Adults have a wingspan of 1 to 2 (35 to 50 mm). Males are highly variable in color. The may be almost entirely light, mostly light but with dark shading in the median area, or entirely dark. The forewings are usually medium-dark reddish-brown. There are two smooth lines: the antemedial line (AM line), between the basal and median areas; and the postmedial line (PM line), that separates the median area from the postmedial area. Aside from two white patches on the fringe, the forewings are otherwise unmarked. On light males, the AM and PM lines are dark, on dark males they are light. The female is light reddish tan and not as variable in color. The hindwings of both sexes are entirely reddish-brown with a faint median band.

The mature caterpillar is 1¾ to 2 long and highly variable in color. Most are pale blue. There is a broad black stripe on the upper middle (middorsal stripe) that has yellow and orange speckling. The speckling may be sparse or dense. In the center of the stripe on each abdominal segment there is a thin blue longitudinal line that does not quite reach the segment ends. The ground color is sometimes dark and the speckling coalesces into large reddish-orange spots. The body is covered with medium-length pale or orange hairs.

 
     
 

Size

 
 

Wingspan: 1 to 2 (35 to 50 mm)

 
     
 

Similar Species

 
     
     
 
Habitat
 
 

 

 
     
 
Biology
 
 

Season

 
 

One generation per year: Late July to early August

 
     
 

Behavior

 
 

 

 
     
 

Life Cycle

 
 

First stage (instar) larvae overwinter in the egg. Eggs hatch in the spring within two weeks of the bud burst of its host species. Early instar caterpillars create a silken group nest and feed within the nest. Late instars feed alone outside the nest. The mature in 30 to 42 days, pupate, and emerge as adults in late July to early August.

 
     
 

Larva Hosts

 
 

Many trees and woody shrubs

 
     
 

Adult Food

 
 

 

 
     
 
Distribution
 
 

Distribution Map

 

Sources

21, 29, 30, 75.

 
  10/14/2020      
         
 

Occurrence

 
 

Common in the west, uncommon in Minnesota

 
         
 
Taxonomy
 
 

Order

Lepidoptera (butterflies and moths)  
 

Suborder

Glossata  
 

Infraorder

Neolepidoptera  
  Parvorder Heteroneura  
  No Rank Ditrysia  
  No Rank Obtectomera  
 

Superfamily

Bombycoidea (hawk-moths)  
  No Rank Bombyciformes  
 

Family

Lasiocampidae (lappet moths)  
 

Subfamily

Lasiocampinae (tent caterpillars)  
 

Tribe

Lasiocampini  
 

Genus

Malacosoma  
       
 

Subordinate Taxa

 
 

western tent caterpillar moth (Malacosoma californicum ambisimile)

western tent caterpillar moth (Malacosoma californicum californicum)

western tent caterpillar moth (Malacosoma californicum fragile)

western tent caterpillar moth (Malacosoma californicum lutescens)

western tent caterpillar moth (Malacosoma californicum pluvialis)

western tent caterpillar moth (Malacosoma californicum recenseo)

 
       
 

Synonyms

 
 

Malacosoma americana (an often repeated error in gender)

 
       
 

Common Names

 
 

western tent caterpillar

western tent caterpillar moth

 
       

 

 

 

 

 

 

Glossary

Antemedial line

A thin line separating the basal area and the median area of the forewing of Lepidoptera.

 

 

 

 

 

 
 
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Other Videos
 
  Malacosoma californicum
Dennis Marlow
 
   
 
About

May 31, 2014

Western tent caterpillar are invading the Pacific Northwest! May2014

While opinions on tent caterpillars seem to vary, there is one thing no one seems to dispute — the little buggers are everywhere.

Estimated by experts to number in the billions, they're wiggling and munching their way across communities throughout Western Washington, and Whidbey Island is no exception.

Trees they plague, consuming leaves and coating branches like a moving bark, but nothing is out of reach: they cover mailboxes, parking lots, walls and even people can't seem to escape.

 
  Western Tent Caterpillars (Malacosoma californicum)
Wandering Sole Images
 
   
 
About

Jun 10, 201

Western tent caterpillars (Malacosoma californicum) near Saint Mary Lake in the East Kootenays of British Columbia.

 
  Tent Caterpillars on the March
wetvideocamera
 
   
 
About

Jun 26, 2012

The Western Tent Caterpillars are on the march. Colonizing new areas. Here they are crossing a bridge. They will have to negociate a busy road to get to new vegetation on the other side.

( Malacosoma californicum ) Vancouver, BC

 
  Western Tent Caterpillars on Tree Branch
Tony Zapien
 
   
 
About

May 4, 2013

Close up video of western tent caterpillars in Bellingham, WA on May 4th, 2013.

Malacosoma californicum, the western tent caterpillar, is a moth of the family Lasiocampidae. It is a tent caterpillar. It is found in the western part of the Nearctic ecozone.

The wingspan is about 28 millimeters.

 
       

 

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Created: 10/14/2019

Last Updated:

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