No. 4.] . THE GYPSY MOTH. 89 



the caterpillar turned into a chrysalis, and ceased eating, of 

 course it was no use to spray longer with Paris green. 

 Then experiments were made as to how they could be 

 destroyed in that state. It was found that there were 

 certain combinations that could be sprayed upon them that 

 would kill them by contact. Something was accomplished 

 in that way. Then they came into the moth stage, in which 

 they remained but a few hours, or long enough to lay their 

 eggs, and we had the rest of the season to work upon 

 the eggs. Our experience in the spring in hunting the 

 eggs on a limited territory had convinced us that it 

 was feasible to fight them in that way, and our force was 

 put to gathering eggs. We proposed to go over all 

 this territory and thoroughly hunt and gather the eggs, 

 but found that there was not sufficient money left of the 

 appropriation to complete the work. We had found 

 by observation that the creature had not occupied new 

 territory of his own will, but had evidently been carried 

 there by teams. The caterpillar does not migrate, he moves 

 only in quest of food. He remains on a tree as long as the 

 food supply is sufficient ; when that is exhausted, he moves 

 just far enough to get something more to eat. We found 

 also that the female moth does not journey on the wing; so 

 that the natural spread of the creature is very slow indeed. 

 Outside the territory that was thoroughly infested, on the 

 main roads here and there a centre of infection had been 

 found, where, in a limited territory, they were quite numer- 

 ous. Investigations proved that in almost every one of 

 those cases wo could determine almost to a certainty how 

 they got there. They would be found in a field where manure 

 had been drawn from the infested district. They would be 

 found about the buildings of a milk peddler who had ped- 

 dled milk in the infested section, going there every day and 

 back to hi* farm. They would be found in places where 

 people from the infested section had often been to visit their 

 friends during the summer, and in picnic places where peo- 

 ple had gone repeatedly back and forth. In every case we 

 found that we could account for its presence outside of the 

 circle of thoroughly infested territory where it had spread 

 by natural causes. These facts are somewhat encouraging, 



