THE SUMMER WORK. 57 



cavities of the tree trunks and in other hiding places, they 

 were destroyed by spraying with insecticides which killed 

 them by contact. The arsenites have no effect when used 

 in this way. Burlap bands were also placed about the trees 

 to serve as artificial hiding places for the caterpillars, and 

 many were destroyed beneath the bands. This method was 

 so successful that it was generally adopted, and more than 

 sixty-eight thousand trees were banded during the season. 



Entomological Work. 



On June 18 Prof. Charles H. Fernald was appointed en- 

 tomological adviser to the committee. Arrangements were 

 made by which he could give a portion of his time to the 

 work, and one of his assistants, Mr. E. P. Felt, was em- 

 ployed in making observations and experiments. Professor 

 Fernald critically examined the field work, reported thereon, 

 and made frequent subsequent visits of inspection to the in- 

 fested territory, directing the experiments and giving advice 

 concerning the work in the field. At his suggestion the in- 

 spectors were directed to watch for parasites of the moth in 

 its various stages. Several parasites were discovered. All 

 dead pupre found during the season in the central towns were 

 collected and preserved, in order that the parasites preying 

 upon them might be obtained. The dead pupae found in the 

 outer towns of the infested territory were left on the trees, 

 that the parasites might escape from them and continue their 

 work. The inspectors were encouraged in their observations 

 on the habits and life history of the moth. The feeding 

 habits were made the subject of especially careful observa- 

 tion, and all the information thus gained was recorded and 

 tabulated for future use. 



Numbers and Destructiveness of the Moth in the Summer of 

 1891. 



Though a great number of eggs had been burned in the 

 spring, and thousands of caterpillars had been killed by 

 spraying, burning, burlapping and other means, they were 

 still so numerous in the summer of 1891 that some dam- 

 age was done in certain localities. A few trees in some 

 orchards in Maiden and Medford were almost defoliated. 



