28 MAINE AGRICULTURAL EXPLRIMe;NT STATION. 1909. 



"Trees of all ages and sizes whether growing in the open or 

 in closed stands seem to be almost equally affected, with two 

 apparent exceptions : ( i ) Large full crowned trees with a 

 diameter of 18 inches or more, standing in the open, seem to be 

 rarely affected; and (2) trees in the interior of a dense stand 

 seem to be more rarely affected than those near the edge. 

 Otherwise the blight seems indifferent to the health or to the 

 situation of. the tree or to the character or moisture of the soil in 

 which the tree is growing." 



In the summary we find the following: — • 



"So far the disease has done but little damage, but it has now 

 obtained such a foothold that if it proves to be infectious it may 

 have serious results. The cause of the trouble is still unknown. 

 The situation is not one which calls for alarm, but simply for 

 watchfulness and investigation." 



In the above discussion nothing has been said with regard to 

 the relation of insects to the present trouble affecting the pines. 

 Fortunately the Station Entomologist, Miss Edith M. Patch, 

 was making the study of certain forest insects one of her impor- 

 tant lines of investigation during the past summer. Conse- 

 quently she had the opportunity and did make quite careful 

 observations on the insects of tHe pine, particularly those found 

 on diseased trees scattered over extensive and widely separated 

 areas in the State. 



In Bulletin 162, p. 366 ]\Iiss Patch after discussing various 

 insects found upon the pine makes the following statement : 

 "On account of the precarious condition of white pine in certain 

 parts of the State considerable alarm has been aroused by vari- 

 ous insects found upon the pine this season and indeed it has 

 seemed as though an unusual number of species had taken 

 advantage of the pines this year. 



Besides the standard borers to be continually reckoned with, 

 the pine sawflies and pine leaf eating caterpillars have made 

 noticeable inroads, while spittle insects and plant lice (Lachmus 

 strohi and Chcrmes pinicorticis have been unusually prevalent. 



None of these insects, however, have been the cause of the 

 'white pine blight,' though several of them Chernies pinicorticis 

 and spittle insects, Aphrophora parallela, for instance, have been 

 in some cases conspicuously associated with the ailing trees." 



