10 FIELD WORK AGAINST GIPSY AND BROWN-TAIL MOTHS. 



a city about 5 miles north of Boston, by caterpillars which appeared 

 in enormous swarms. In many cases the trees were completely 

 defoliated, and the insects crawled into the houses and upon the 

 fences and walks, so as to become a public nuisance in the neighbor- 

 hood. Specimens were sent to the office of the Massachusetts state 

 board of agriculture at Boston, and were transmitted to Prof. C. H. 

 Fernald, at Amherst, and, in his absence, were determined by Mrs. 

 Fernald as the gipsy moth of Europe. An investigation in the neigh- 

 borhood showed that this insect had been quite abundant and had 

 caused considerable damage for a number of years, but, owing to the 

 belief of most of the residents that it was one of the common native 

 caterpillars, no action had been taken in the matter. As a result of 

 persistent inquiry among the inhabitants of the infested section it was 

 determined that some of these insects were introduced from Europe, 

 probably in the egg stage, by Prof. Leopold Trouvelot, a French 

 naturalist, about the year 1869. At that time this gentleman was 

 conducting experiments with silkworms, and also with some of the 

 American species of silk-spinning caterpillars. The evidence seems 

 to show that some of the egg clusters, or young caterpillars, which 

 he secured from Europe, escaped from his house where the experi- 

 ments were being conducted, and, as he was aware of the dan- 

 gerous nature of the insect in its native home, he destroyed all the 

 caterpillars that could be found in the neighborhood and made public 

 the fact that it had escaped. At that time the section in which he 

 resided adjoined a large area of waste land, which was overgrown 

 with sprouts and brush, and here the species became established. 

 Its slow development as a serious pest was undoubtedly due to the 

 fact that this area was burned over periodically by brush fires which 

 destroyed large numbers of the insects, and also to the prevalence 

 at that time of many insectivorous birds, which doubtless accom- 

 plished much in preventing the rapid increase of the species. 



So thoroughly were the trees defoliated by the caterpillars that 

 in many cases during the summer of 1889 and 1890 swarms of 

 them practically covered the sides of many houses. Real estate 

 in the neighborhood rapidly depreciated in value and many tenants 

 moved to more congenial quarters of the city. The recorded state- 

 ments of eye-witnesses of the conditions that prevailed seem almost 

 incredible to one who has had no opportunity to observe the serious 

 damage which this insect causes. Many trees and orchards died 

 as the result of repeated defoliation, and during the winter of 1890, 

 on petition of the city of Medford and the surrounding cities and 

 towns, the matter was brought to the attention of the legislature, and 

 the sum of $25,000 appropriated for abating the nuisance. 



