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NEW TOitK STATE MUSEUM 



molt for the last time, and the males spin their ova*! cocoons 

 (fig. 4). The delicate, four-winged reddish male is rarely seen 

 although of particular interest from its presenting a partially 

 developed form known as the pseudimago. 



Fig. 4.— Cocoons of male (three times natural size) 



Means of distribution. As the slender males only are 

 winged, the insect is dependent largely upon various agencies 

 for its distribution. It has most probably been carried to Ne- 

 vada, California and other distant localities on infested nursery 

 stock, but this does not explain its general occurrence in such 

 cities as Albany and Troy. In these two places, at least, the 

 distribution appears to have been largely effected by the aid of 

 the English sparrow and other birds, since the active young could 

 easily crawl upon the foot of a bird and thus be transported to 

 another tree. Other insects may also transport them to a certain 

 extent and some, falling with the leaves, might successfully make 

 their way up another tree, but the chances are against the latter 

 method. 



SECONDARY ATTACKS BY INSECTS 



It is well laiown to students of nature that an infeebled tree 

 apparently invites attack by certain insects which seem to find 

 in the unhealthy tissues conditions peculiarly fitted for their 

 development. The ravages of the elm-leaf beetle have encour- 

 aged certain of these pests to a marked degree. One of the most 

 common and injurious is known as the pigeon Tremex, Tremex 



