Saturday, June 1, 2013

Forest Tent Caterpillar

Preston's favorite caterpillar
During the nature hike with Troop 200, several scouts found this caterpillar on small maples or other trees as well as wandering along on the ground.  One of them clung to a twig for the entire hike and made it back to the house for identification.

Troop 200 forest tent caterpillar- click to enlarge
Side View- Charles Lewallen
This is the forest tent caterpillar  (Malacosoma disstria) which becomes a moth of the same name.  In addition to the distinctive round spots along the back it has beautiful turquoise stripes running along each side.

Troop 200 cocoon
When you spot a caterpillar on the ground, it usually has either dropped to escape a predator or is wandering around looking for a safe place to pupate (make its cocoon or chrysalis).  After identifying this cat, I put it and another one I found on the ground into a ziplock with some leaves.  Two days later, violĂ , I now had two fuzzy cocoons.

When the moths emerge, they mate and the female lays masses of up to 300 eggs.  These are glued to branches with a substance that also protects them from freezing over the winter.  The larvae emerge in the spring and immediately start feeding.  In the Ozarks they are especially fond of oaks and maples.
In spite of their name, they do not make tents like the eastern tent caterpillars that are common on Prunus species.  They are social, traveling and feeding in masses and during large outbreaks they may strip an individual tree of its leaves.  This isn't usually a significant problem in a forest but can cause consternation to an affected homeowner.  Outbreaks tend to occur for several years in a row, especially after seasons of harsh climate or heavy predation.  After last year's drought, we may be seeing lots of these moths in the next few years.

Our official Troop 200 M. disstria  should eclose (emerge from the cocoon) within the week.  I will attach its picture to this blog.  Until then, the one above will have to do.

A comprehensive resource on forest tent caterpillars is at

No comments:

Post a Comment