86 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 7 



SiLVICULTURAL INVESTIGATIONS 



This work has been taken up in cooperation with the U. S. Forest 

 Service and is being conducted by Mr. G. E. Clement. Its object is 

 to determine the relative resistance to moth attack of different species 

 of timber trees when grown under the best silvicultural condition. 

 The method used in carrying on this work is to select different types 

 of forest growth and put them into the best possible silvicultural 

 condition. These plats are examined from time to time to secure 

 information on the effect of such thinnings and to test the ability of 

 different stands to survive gipsy moth attack. The results of these 

 experiments will give valuable information as to the proper method 

 of managing moth-infested woodlands. 



Quarantine Work 



The territory infested by the gipsy moth and the brown-tail moth 

 has been placed under quarantine by the Federal Horticultural Board, 

 and regulations have been made providing for inspection of nursery 

 stock and forest products that are shipped from the infested territorj^ 

 to other parts of the United States, in order to prevent the spread of 

 these insects on such shipments. This work is in charge of Mr. D. M. 

 Rogers, and all products of this sort that are shipped outside of the 

 territory are carefully inspected. This protects the country at large 

 and has resulted in preventing the spread of both the gipsy moth and 

 the brown-tail moth to many widely separated sections of the United 

 States. 



Scouting Work 



This work is being carried on under the direction of Mr. L. H. Worth- 

 ley, and consists in the examination of the territory around the outside 

 border of infestation. It serves to determine the territory which 

 should be placed under quarantine from year to year. As much work 

 as possible is done to clean up infested places in this outside territory, 

 particularly along the western border, from which section the insect is 

 most likely to spread to other parts of the country. Careful work 

 is being done in several isolated colonies beyond the principal area of 

 infestation, and in some places the insect has been exterminated before 

 there was opportunity for further spread. 



Cooperative Work 



Field work is being carried on in close cooperation with the work 

 that is done in the infested states, and which is being paid for by state 

 or local appropriations. Arrangements are made so as to prevent a 

 duplication of work and in this way good results have been secured. 

 Cooperation with the states has also been attempted with good results 

 in introducing and checking up the work of the parasites and natural 



