Prairie Ridge Ecostation

Eastern Tent Caterpillars

Malacosoma americanum

Have you noticed the silken tents in the branches of neighborhood fruit trees? These tents are the temporary homes of the Eastern Tent Caterpillars (Malacosoma americanum).

Did you know that these caterpillars are some of the earliest to become active in the spring? They are able to do this by relying on their tents as shelter during the cooler days of spring.           

Why are they often found in fruit bearing trees? These caterpillars, like many others, are  very picky eaters and will only eat the leaves of certain fruit and hardwood trees. They are most often found at Prairie Ridge in Black Cherry trees (Prunus serotina) and Bradford Pear trees (Pyrus calleryana).

How do they seem to follow each other? When the caterpillars leave the tent they do so en masse. As they travel they leave a  pheromone trail. The caterpillars will then follow this pheromone trail to reach food more efficiently.

The empty egg mass of a colony of Eastern Tent Caterpillars         The characteristic silken tent in the branches of a Bradford Pear tree         Caterpillars following one another

Do these caterpillars turn into butterflies? No, instead they pupate into moths. They will crawl on the ground away from the  tent to find a good place to make a cocoon.

                      A caterpillar looking for a place to pupate             Measuring our Tent Caterpillars

Do you have tent caterpillars in your neighborhood? If so, we would like to hear about them. We are measuring the size of our tent caterpillars here at Prairie Ridge. On Thursday, March 27 they were  approximately 0.5 inches long. E-mail us the size of your caterpillars, date and  time you measured them, and the city you live in.

Find out more about the natural happenings at Prairie Ridge at our What Time Is It In Nature Archive.