Eastern tent caterpillar (Malacosoma americanum)
Tent Caterpillars are medium sized species of caterpillar in the moth family
Lasiocampidae . Twenty-six known species occur in North America, Mexico and Eurasia.
Consider by most to be pests due to their defoliation of trees, they are among the most social of all caterpillars. Tent caterpillars are easily recognized because they are social , diurnal and build obvious silk tents in the branches of trees. These large tents are occupied through the whole of the larval stage. Tents serve as aggregation points and as focal sites to body temperature. They also serve as communication centers where caterpillars alert each other about the discovery of new food. The tent is constructed at a site that intercepts the early morning sun. The caterpillars need to bathe in the sun to raise their body temperatures above the cool ambient temperature in the early spring. This is because when the body temperature of the caterpillar is less than about 15 °C, digestion cannot occur. The tent consists of many silk layers separated by gaps and the temperature in these layers can vary greatly. Caterpillars can adjust their body temperatures by moving from one compartment to another. On cool mornings they rest in a tight aggregate just under a sunlit surface of the tent. When attempting to remove an infestation from a tree, it is important to wait till evening when all the caterpillars have returned to the tent to rest and digest their food.