SUPPRESSION OF THE GIPSY AND BROWN-TAIL 

 MOTHS AND ITS VALUE TO STATES NOT IN- 

 FESTED. 



By A. F. BURGESS, 



In Charge of Gipsy Moth and Brown-tail Moth Investigations, Bureau 

 of Entomology. 



MANY years ago a circumstance occurred at Medford, 

 Mass., which was destined to cause enormous expense 

 and trouble in that community and throughout the neighbor- 

 ing States. About 1869, Prof. Leopold Trouvelot, a French 

 naturalist who was a resident of Medford, introduced a few 

 egg clusters of the gipsy moth for the purpose of con- 

 ducting experiments on silk culture. During the course of 

 the experiments some of the caterpillars escaped. Realizing 

 that the insect was a serious pest in Europe, he made a care- 

 ful search on the trees and in the woodland nearby for the 

 purpose of destroying any that could be found. He also 

 notified the Department of Agriculture at Washington. 

 None of the insects which had escaped could be found, but 

 as no injury resulted during the next few years, it was 

 thought that the matter was not of great importance. 



About 20 years later the neighborhood was invaded by 

 swarms of caterpillars which were supposed by most of the 

 residents to be a native species that had become unusually 

 abundant. A study of the matter developed the fact that 

 the insect which was defoliating the trees was the notorious 

 gipsy moth of Europe and that it had become firmly estab- 

 lished in the locality in which it had originally escaped and 

 throughout the immediate surroundings. Its slow increase 

 seemingly was remarkable, but this has been accounted for 

 by the facts that the wood and brush land in the neighbor- 

 hood was burned over every few years by forest fires, that 

 insectivorous birds and other natural enemies were at that 

 time abundant in the neighborhood, and that the destruction 

 of a few caterpillars when the species was very rare would 

 result in holding down the increase for a number of years. 



The city of Medford and the State of Massachusetts soon 

 interested themselves in a campaign to destroy this insect. 

 It had become so abundant in many places during the early 

 nineties that the trees in the residential sections were de- 



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