Malacosoma americanum                                      Photo Fiona Sunquist ©

Tent caterpillars show up in spring just as the new leaves appear. They prefer to build their tents in wild cherry, crabapple, plum and peach trees. During the day, the caterpillars leave the tent and move out along the branches to find leaves to eat, after feeding they return to the tent to digest their food.

                                                                          Photo Fiona Sunquist ©

The tent is always built in a location that gets early morning sun, because the caterpillars must bask to bring their body temperatures up so they can digest food. The caterpillars grow fast, and in seven or eight weeks they move to protected places where they spin their cocoons - two weeks later the reddish-brown adult moths emerge.

The moths live for only a short time and are rarely seen. The female moths die after laying their eggs, often within 24 hours of emerging from the cocoon, males may live for a week.

Tent caterpillar populations fluctuate in a ‘boom and bust’ cycle, and often cause great concern when masses of them move across sidewalks and roads. However, they are primarily a nuisance, unsightly and annoying, but not dangerous. Though they can almost completely defoliate a tree, the tree usually recovers and puts out new leaves.

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