Defoliators
> Forest Tent Catepillar
Pest: Forest Tent Caterpillar (Malacosoma disstria Hubner)
Order: Lepidoptera
Family: Lasiocampidae
Host Plants
Several different deciduous hosts including: Oak (Quercus
), Maple (Acer ), Poplars (Populus ), Birch (Betula
), Ash (Fraxinus ), Elm (Ulmus ), others.
Description:
Although being similar to the eastern tent caterpillar in the
larval stage, they do not make a noticeable web. These larvae tend
to climb higher in the host trees and are more dispersed throughout
the host. They are a defoliator and in high population numbers can
cause serious defoliation to the host plant. Usually, however, their
numbers are moderate to low and most of their feeding injury goes
unnoticed. The larvae can sometimes be seen clustered
in a large group on the trunk of the host.
Life Cycle:
The forest tent caterpillar over-winters as an egg in a shiny,
black eggmass that is very similar in appearance to that of the
eastern tent caterpillar. Where the eastern tent caterpillar’s
egg mass is somewhat tapered at both ends, that of the forest tent
caterpillar is square on the ends. Eggs hatch near the time of budbreak
on the host plant and young larvae can create much damage to the
newly expanding foliage. Afterwards, they will continue to feed
on the fully expanded foliage. Pupation occurs from mid-late , in
Massachusetts, and adult moths appear soon thereafter. There is
only one generation per year.
Management Strategies:
Insecticidal soaps can be used on young larvae but proper coverage
may be difficult on larger trees. Bacillus thuringiensis
(B.t.) is effective on the younger larvae as well.
This species does not produce a noticeable silken web that can
be removed as with other species, such as the fall webworm and eastern
tent caterpillar.
Many chemical insecticides are also labeled for this pest.
Eggs hatch around 192 growing degree days and the larvae actively
feed for 5-6 weeks.
Images:
| 
A cluster of new forest tent caterpillars on a tiny silken
mat atop an individual leaf. This is all the silk that this
species will produce. (R. Childs)
A cluster of older forest tent caterpillar larvae on the trunk
of a tree. Many dozen caterpillars may cluster like this for
hours but then disperse throughout the tree for feeding. (R.
Childs).
A forest tent caterpillar larva. Note the white "foot print"
or "key hole" markings along the back. (R. Childs).
A forest tent caterpillar and its injury to host plant foliage.
(R. Childs).
|
Defoliators
index:
Armyworm
Asiatic Garden Beetle 
Bagworm
Cankerworms
2006
Caterpillar Update
Eastern Tent Caterpillar
Fall Webworm
Forest Tent Caterpillar
Gypsy Moth
Japanese Beetle
Larch Casebearer
Lily
Leaf Beetle -
Courtesy of URI Extension
Mimosa Webworm
Viburnum Leaf Beetle
Winter
Moth - ID & Management
UPDATED! Winter
Moth Overview
Winter
Moth Project - Biological Control in MA
Questions
about downloading files followed by the
symbol? Click
here for more info.
|
