Il8 MAINE AGRICULTURAL EXPERIMENT STATION. 



Vulnerable Points and Remedies. 

 The young larvae of all the broods are exposed when they first 

 hatch and before their leaf shelter is made. The same remedies 

 apply to this insect as to the bud moth. 



THE FOREST TENT CATERPILLAR. CHsiocampa disstua, Hiibner. 



There are two tent caterpillars in the eastern United States; 

 the apple tree tent caterpillar, CHsiocampa Americana, and the 

 forest tent caterpillar, which was called by Prof. Harris CHsio- 

 campa sylvatica, but in recent literature is known as CHsiocampa 

 disstria. Both species are common in Maine but are often con- 

 founded. Though similar in their life history, they are readily 

 separated by differences in the egg clusters, caterpillars and 

 moths. 



Distinguishing Characteristics. — Egg clusters of this species, 

 the same diameter throughout, docked off squarely at the ends; 

 caterpillars with a row of spots along the back ; oblique lines on 

 the wings dark colored ; web inconspicuous, closely attached to 

 the limbs or trunk and easily overlooked. Insect restless, wan- 

 dering from tree to tree. Occurs in orchards but, being a gen- 

 eral feeder, is more commonly found on forest or shade trees, 

 from which habit it receives its common name. 



Description. 



J^SS^- — The egg clusters, composed of about 300 to 400 eggs, are 

 attached to the terminal twigs of the food plant. They are of the same 

 diameter throughout and cut off squarely at the ends. The eggs are 

 creamy white, rounded at the base, enlarging upwards, narrowing again 

 at the top and terminated by a circular rim on the border and a sunken 

 spot in the center. They are held to the twig and to each other by a 

 brown varnish, which also covers the egg clusters, protecting them from 

 the weather and probably from their enemies. 



Larva. — The eggs hatch in the early spring, usually about the time the 

 buds are bursting. The time, however, varies with the exposure of the 

 egg clusters to the sun, and also with the season. In Maine they are 

 hatched the last of April or early in May. Sometimes, during continued 

 warm weather, the eggs hatch before the leaves start, and cold weather 

 comes on afterwards. The young larvae are very hardy, however, and 

 are not often killed. We have kept them alive in breeding cages for three 

 weeks without food. They will eat the varnisti on egg clusters. As 

 soon as hatched they spin a web wherever they go, possibly to enable 



