CONTROL OF GIPSY MOTH BY FOREST MANAGEMENT. 43 



STAND AT NORTH BERWICK. MAINE. 



MANAGEMENT OF A TYPICAL STAND OF NORTHERN HARDWOODS WITH NO WHITE OAK. 



This lot, 4 miles from a prosperous manufacturing town, while 

 within the white-pine region, had a stand characteristic of the 

 northern hardwoods region. It contained 14 species of trees on 3.4 

 acres, but 98 per cent consisted of the following nine species in the 

 proportions indicated : 



Per cent. 



Black birch 4 



Yellow birch 3 



Hop hornbeam 16 



Nine species 98 



Per cent. 



Red oak 2 



Paper birch 2 



Beech 45 



Hemlock 4 



Red maple 8 



Sugar maple 14 



The soil is a sandy loam, deep and well drained. The surface is 

 very uneven, steep in places and thickly covered with large stones 

 and small boulders. 



The trees averaged 6.5 inches in diameter, breast high, but varied 

 greatly in size, the average for the different species ranging from 3 

 to 15.2 inches, with a few individual trees ranging up to 31 inches in 

 diameter. The gipsy-moth infestation in 1913 was exceedingly light, 

 only one egg cluster per acre, and had not increased much by 1915, 

 although in that year other woodlots in the neighborhood were 

 severely defoliated. 



Under present economic conditions the general application of 

 forest management to such lots as this is not to be expected, but the 

 possibility of controlling the gipsy moth by this means is considered 

 here, to complete the comparison between typical stands found 

 within the white-pine region, and for its possible application in 

 special cases. The Class I trees (favored food of the caterpillars) are 

 red oak, paper birch, and beech. Of these beech is the least valuable 

 commercially, unless there happens to be a local demand for the wood, 

 but it is the most desirable from the standpoint of gipsy-moth control. 

 As a result of his observations, Mosher draws this conclusion : " It is 

 evident that the beech must be associated in a mixture with one or 

 more favored species in order that the gipsy moth may reproduce 

 normally." 



Anything which adversely affects the normal reproduction of the 

 moth is of value as a control measure. Mosher's conclusion as to 

 beech would place it for purposes of control by forest management 

 among Class III trees, especially if other Class I trees were removed 

 from the stand. It should also be remembered, in this connection, 

 that there is a wide range in susceptibility to gipsy-moth attack, not 



