GYPSY AND BKOWN-TAIL MOTHS AND THEIR CONTROL 23 



In the generally infested area it is impracticable to apply such 

 intensive methods to large woodlands unless the property is of special 

 esthetic value or to protect other areas that have been intensively 

 treated. On account of the low value of most of the forest growth, 

 some relief can be obtained by the adoption of a thinning program 

 based on the removal of the most favored food trees in order that the 

 food of the insect may be reduced. This work, together with the 

 encouragement of the growth of nonfavored species, will assist in 

 preventing damage by this insect. It can be done by the owner 

 himself if he makes proper selection of the trees to be removed. 

 Obviously the best silvicultural practice should be followed in such 

 selective thinning (figs. 10 and 11). In pure or nearly pure stands of 

 favored trees clean cutting and the planting of unfavored species is 

 the best method of building up a resistant stand even though the cost 

 is considerable, but there are many areas scattered through the 

 infested territory where clean cutting is not necessary to improve 

 the stand. 



The same principles of thinning, aimed at the creation of more 

 resistant growth, can be applied by owners even if their property is 

 not infested, as this will reduce the opportunity for establishment of 

 this pest. In young plantations of white pine or other conifers favored 

 species should be removed, and if there are adjoining areas of favored 

 growth as many of such species as possible should be removed to 

 prevent the insect from migrating into the plantations. 



RECENT CONTROL WORK IN NEW ENGLAND AND NEW YORK 



WOODLANDS 



In both the barrier zone and the outlying infested areas intensive 

 work is being done, most of it in woodland, to exterminate the insect 

 and to prevent westward spread. In the zone itself such treatment has 

 eliminated the insect in many localities in Vermont, Massachusetts, 

 and New York. Isolated colonies are now (1937) being treated in 

 southwestern Massachusetts and northwestern Connecticut, and in a 

 few towns in the southern part of New York State. On Long Island 

 and in the Borough of the Bronx in New York City the infestation 

 has been greatly reduced. In 1936 a colony was found in Shawangunk, 

 west of the Hudson River, and intensive treatment is being applied 

 in this locality. 



Between the barrier zone and the Connecticut River isolated colonies 

 have been found, especially in the territory nearest the river in 

 Vermont and over a wider area in Massachusetts and Connecticut. 

 Work similar to that in the barrier zone is being carried on here, the 

 number of infestations is being reduced, and infestations have been 

 exterminated. 



RECORD OF CLEAN-UP OF OUTLYING COLONIES 



A few colonies of the gypsy moth have been discovered at points 

 quite distant from the generally infested New England region, 

 notably at Geneva, N. Y., in 1912; at Cleveland, Ohio, in 1914; at 

 North Castle, Westchester County, N. Y., in 1914; at Rutherford, 

 N. J., in 1914; and at Greenport, near the eastern end of Long Island, 

 in 1921. In practically all these cases the Federal Government was 

 assisted by the States involved in ferreting out the limits of the 



