108 >"E\V YORK STATE MUSEUM 



forests over hundreds of square miles in the Southern States, and tlial in the 

 vicinity of Memphis, in 1862, the larvae were so abundant as to fre(]uently 

 stop trains gointj in and out of the city. In 1889 another instance of trains 

 heiny stopped was broujj^ht to tlu; notice of the division of entomoloi^y, 

 L'nited States Department of Agriculture {^Iiisccl Life. 1889. 2:58]. 

 This time the trouble was in Maine and was accompanied by serious injury 

 to forests and orchards. Two years later trains were stopped on the 

 Carolina Central Railroad near Lumberton \Inscct Life. 1891. 3:477], 

 and hindrance to travel was accompanied by the defoliation of many trees 

 over large areas. This species was e.xcessively injurious in the vicinity of 

 London Ont. in 1877, as recorded by William Saunders in the following 

 words: "There were millions upon millions of them, and so enormous were 

 their numbers and so persistent their attacks, that after fighting them 

 bravely for a week or two, many gave up the contest in despair, weary of 

 the slaughter. Many an orchard was rendered bare and leafless and in 

 some instances the wootls were so \()id of foliage as to remind one of 

 winter." In southern Illinois this insect "made a frightful inroad upon the 

 apple orchard, absolutely defoliating every tree in large districts in 1883." 

 The damage of the last few )ears in New ^'o^k State has been duplicatetl 

 to a great extent in Vermont and New Hampshire. 



The caterpillars committed very extensive ravages in 1897 along the 

 Ottawa river, stri|)])ing the aspen groves of every leaf and seriously injuring 

 other trees \Ottinva Naturalist. 1898. 12: 13]. 



Distribution. The numerous records of serious injury by this insect 

 in the eastern United States and Canada indicate that it is widely and 

 generally distributed. It has been reported from Mississippi north into 

 Canada and from Maine westward to California. Dr Dyar states that M. 

 disstria extends throughout the range of M. americana and M. 

 p 1 u v i a 1 i s and also into California. 



Description. This insect can be distinguished at once from the com- 

 monly injurious tent caterpillar, Malacosoma americana Fal)r., by the 

 fact that no conspicuous web tent is spun. This caterpillar | pi. 7, hg. 13] 



