132 THE SPINY ELM CATERPILLAR 



also one of their having fed greedily upon the leaves of rose,. 

 and another of their having almost defoliated a pear tree. 

 Linden and nettle are also included in the European lists of 

 the food-plants of this species. It is evident, however, that 

 all of these except the three first named willow, poplar, and 

 elm are to be regarded as exceptional cases, and that the 

 normal food of the species is the foliage of a plant belonging 

 to one of these three genera. 



BROODS AND HIBERNATION 



It has generally been supposed that this species is double- 

 brooded in central and southern New England, the butterflies 

 of the first brood appearing early in July. These are said to- 

 deposit eggs which hatch into caterpillars that mature into- 

 butterflies early in September. These butterflies live through 

 the winter, laying eggs the following spring. 



Unless the summer of 1899 was exceptional, however, this- 

 idea of the yearly history of the species will have to be modi- 

 fied, for during this season, in New Hampshire and Vermont 

 at least, there was practically but one brood. Continual! 

 observations by Miss Caroline G. Soule at Brandon, Vt., and 

 by Mr. Fiske and myself in this state show that there was 

 scarcely a trace of a second brood of caterpillars, for with all 

 our searching in July and August we found but a single col- 

 ony of larvse. These were discovered on a willow at Durham 

 August 3. During the period when the second brood of cat- 

 erpillars are supposed to be at work, I traveled by carriage and 

 on foot over hundreds of miles of roadway in southern New 

 Hampshire and southern Maine, and though there was every- 

 where evidence of the presence of the first brood, none of the 

 second were seen. During the same period Miss Soule was 

 watching in the region of Brandon, Vt., and Mr. Fiske took an 

 extended trip through central New . Hampshire. But save 

 for the single colony mentioned, all our looking did not reveal; 

 a trace of the second brood. Nor was there a single com- 

 plaint from correspondents of injury at the supposed time of 

 the second brood, although many accounts of the depreda- 

 tions of the first brood were received. 



