Other Tent Caterpillars

There are a number of other caterpillars that resemble Forest Tent Caterpillar or that might be found at similar times.

Prairie tent caterpillar (Malacosoma californicum lutescens)

• Chokecherry is primary host, but also attacks various hardwoods
• Adults = light brown to dark tan coloured moths with whitish band across forewing
• Egg masses are laid within 12 inches (30cm) of the ground, on the base of the host plant
  • Masses do not encircle the stem
• Larvae have black backs, with a white-coloured mid-back stripe. The sides of the body are light blue and larvae are hairy.
  • Larvae feed for 6-8 weeks and then spin a cocoon, emerging as adults after a 3-week pupation period
• Single generation per year

Northern (formerly Western) tent caterpillar (Malacosoma californicum pluviale)

• Pin cherry, willow and chokecherry are primary hosts, but also attacks hardwoods
• Adult moths resemble PTC very closely
• Egg masses are laid within 12 inches (30cm) of the ground, on the base of the host plant
  • Masses do not encircle the stem
• Larvae emerge in spring and form a silky nest near a fork in the stem
  • Larvae are black when young, but that is overlooked as they age and develop conspicuous markings
  • They have a broken white stripe along the mid-back, along with broad orange bands enclosing bluish-white and black markings; Larvae are hairy.
• Larvae feed for 6-8 weeks and then spin a cocoon, emerging as adults after a 3 week pupation period
• Single generation per season

Eastern tent caterpillar (Malacosoma americanum)

• Host crops = Pin cherry and chokecherry (principal), but may attack hardwoods
• Adult moths resemble PTC very closely
• Eggs are laid in masses that encircle small twigs and are covered with a frothy covering
• Larvae emerge in spring and form a silk nest at a fork in the stem
  • Larvae are black, sparsely hairy and have a white stripe along the back, as well as narrow, orange stripes parallel on the mid-back and white and blue markings on the sides
• Larvae feed for 6-8 weeks and then spin a cocoon, emerging as adults after a 3-week pupation period
• Single generation per season

Ugly Nest Caterpillar (Archips cerasivorana)

• Host crops = chokecherry, pin cherry, black cherry, other hardwood trees and shrubs
• Adults are yellowish-orange moths, active from mid-summer through September
• Eggs are laid on barks of trees
  • Eggs hatch as leaves emerge
• Larvae emerge and feed within a nest of silk and foliage (including several branches) constructed at the top of the plant from May to September
  • Larvae are approximately 1 inch (20-23mm) long, yellowish-green, with small dark spots and dark heads
• Pupation occurs within the nest
• Single generation per year

Management:

• Management strategies are similar to Forest Temt Caterpillar, including chemical, biological and cultural controls
• Prune out egg masses and silk nests when discovered – removing larvae will reduce populations
• Registered chemical applications may be made to control younger larvae
• The application of BTK can be effective when larvae feed on treated leaves – the baterium must be consumed – contact application is not effective.