2 U. S. DEPARTMENT OF AGRICULTURE BULLETIN NO. 484. 



Bureau, of Entomology have developed a number of important facts 

 not formerly recognized. Among these are the following: (1) The 

 foliage of some species of trees is more acceptable as food to gipsy- 

 moth caterpillars than that of other species. (2) Caterpillars in the 

 first stage of their development do not eat the foliage of conifers, 

 except tamarack. These two facts apparently open up a considerable 

 held for the use of forest management in the control of the insect. 



Toward the end of the year 1912 Mr. W. F. Fiske, of the Bureau 

 of Entomology, called attention to the gipsy moth as a forest insect 

 and suggested the possibility of control by forest management. 1 

 In January, 1913, a cooperative agreement was entered into between 

 the Bureau of Entomology and the Forest Service, providing for a 

 full investigation of this matter. This investigation is now under 

 way. It is based on the belief that infestation of woods can be re- 

 duced and possibly controlled by eliminating the species of trees 

 which are particularly favored as food by gipsy-moth caterpillars 

 and replacing such species with others which are less favored. 



The object of the investigation is twofold. It is desired to ascer- 

 tain in the first place in what proportions trees of different species 

 can be associated to form stands which will not be subject to gipsy- 

 moth ravages, and in the second place, the best method of converting 

 existing stands into others better able to resist attack. 



The plan for the work of this investigation provides for the estab- 

 lishment of sample plots in different kinds of typical forest stands in 

 the infested region. Stands varying in composition, quality, age, cli- 

 matic situation, and degree of gipsy-moth infestation are to be sub- 

 jected to different forms of management with a view to determine 

 what forms produce the safest stands, and the best methods of es- 

 tablishing the most favorable conditions. During the past three 

 years 46 sample plots have been established, and much of the pre- 

 scribed work has been done on them. Several years must elapse 

 before conclusions can be drawn from these experiments. 



In the course of carrying out the work just referred to a number of 

 facts have been observed, and it is believed that a presentation of 

 these facts may be of interest. 



BEHAVIOR OF THE GIPSY MOTH IN THE WOODS. 



The gipsy moth may be introduced into forests by the wind, 2 by 

 caterpillars crawling from adjacent infested areas, or by transporta- 

 tion by man or animals. 3 The caterpillars begin feeding as soon as 



1 Fiske, W. F. The Gipsy Moth as a Forest Insect, U. S. Dept. Agr. Bur. Ent. Circ. 

 164. 20 p. 1913. 



2 Collins, C. W. Dispersion of Gipsy Moth Larvae by the Wind, U. S. Dept. Agr. BuL 

 273. 23 p., 6 pi., 1 map. 1915. 



3 Burgess, A. F. The Dispersion cf the Gipsy Moth, U. S. Dept. Agr. Bur. Ent., Bui. 119. 

 62 p., 6 fig., 16 pi., map. 1913. 



