INSECTS 187 



leaves, but soon commence to spin their winter webs. A number 

 of leaves in the vicinity of the egg clusters are drawn together and 

 carefully spun in with a tenacious silken web, which is grayish in 

 color, composed of dead leaves and silk, and very hard to tear 

 apart. Each web contains about 250 caterpillars and varies in 

 length from 4 to 6 inches. With the approach of cold weather 

 the caterpillars enter the web and close the exit holes. We then 

 have the strange phenomenon of a caterpillar only a quarter grown 

 living through the winter and emerging the following spring to 

 complete its life. The extremes of cold in Massachusetts, where 

 they are so common, do not seem to affect these insects adversely. 

 They emerge in the spring, usually early in April, eat first the 

 buds and then the blossoms, and attack the foliage of fruit trees 

 as soon as it develops. Unlike the gypsy-moth caterpillars they 

 habitually feed by clay. Stripping one tree of its foliage, they go to 

 others and continue to eat until full grown, when they spin their 

 cocoons within the leaves at the ends of the branches or some- 

 times on the tree trunks. The full-grown caterpillar is about 

 2 inches in length, with a broken white stripe on both sides and 

 two conspicuous red dots on the back near the posterior end. 



The pupa. The caterpillars pupate within their cocoons, most 

 of which are formed at the tips of twigs within a spray of leaves, 

 but at times are made on house walls, fences, tree trunks, etc. 

 The pupa is a compact, dark-brown body, about | inch long, with 

 yellowish-brown hairs scattered over its surface. Pupation takes 

 place the latter part of June, and the moths emerge about the 

 middle of July. 



Distribution. The brown-tail moth is known to have spread at 

 least as far to the northeast as Eastport, Maine, and as far south 

 as Cape Cod, Massachusetts. In western Massachusetts it has 

 been found at Amherst, North Adams, and Clarksburg, while the 

 eastern part of the state from north to south is now quite solidly 

 infested. The moth doubtless also exists in many communities in 

 Massachusetts and other states which have not yet been reported. 



The female brown-tail moth, like the male, is a strong, swift 

 flyer, and can carry her eggs long distances before depositing 

 them. For this reason, this moth has spread much farther from 

 its point of introduction in Massachusetts than has the gypsy 



