62 FIELD WORK AGAINST GIPSY AND BROWN-TAIL MOTHS. 



importation and against the transportation in interstate commerce 

 of diseased nursery stock or nursery stock infested with injurious 

 insects, and making an appropriation to carry the same into effect' ' 

 is now under consideration by the Committee on Agriculture of the 

 House of Representatives and it is earnestly hoped that it may 

 receive favorable action. The urgent need of some legislation of this 

 character should be apparent to any person who has given the matter 

 serious thought. From a financial point of view it is much easier 

 and cheaper to stamp out a few insects before they have had an 

 opportunity to gain a foothold in this country than to attempt to 

 exterminate or suppress them after they have had a chance to multi- 

 ply and become acclimated. 



EXPERIMENTAL WORK IN THE CONTROL OF THE GIPSY AND 

 BROWN-TAIL MOTHS. 



During the progress of the field work on the gipsy and brown-tail 

 moths it has been necessary to carry on a limited number of experi- 

 ments and to make investigations so that more economical methods 

 could be used in destroying these insects. It has been known for 

 years that a single defoliation will cause the death of pine or other 

 coniferous trees and some of the men engaged in the field work 

 reported that small caterpillars of the gipsy moth did not appear to 

 feed on the foliage of these trees. In 1907 Mr. F. H. Mosher, one of 

 the entomologists connected with the Massachusetts work, carried 

 on an extensive series of experiments in feeding newly hatched 

 gipsy-moth caterpillars on pine foliage. The results secured showed 

 that the caterpillars would starve rather than eat the food offered, 

 and as a result of this test it became evident that it was necessary for 

 the small caterpillars to have a considerable amount of deciduous food 

 before they were able to attack pine. Using these experiments as a 

 basis, an extensive field test was made in the spring of 1908 by the 

 Bureau of Entomology in cooperation with the Massachusetts state 

 office. 



An area of about 5 acres of pine woodland located in Arlington, 

 Mass., was selected for the test. The woodland was surrounded by 

 farm land upon which were growing many fruit and shade trees, as 

 well as a considerable amount of brush and undergrowth, all of which 

 was very badly infested with the gipsy moth. The pine trees were 

 banded with tanglefoot early in the spring and no other treatment 

 was applied except combing the bands. These trees, as well as the 

 deciduous trees on the surrounding ground, were badly infested with 

 egg clusters of the gipsy moth. After the caterpillars hatched, the 

 deciduous trees were badly defoliated, but no injury resulted to the 

 pines. The small caterpillars in the pine trees, being unable to secure 



