60 ENTOMOLOGICAL SOCIETY 



ber so attracted was so few in comparison with those that 

 swarmed to the trees, that I have been led to reverse my 

 opinion as to the value of this mode of destroying the beetles. 



The experience has a certain value, and I would draw the 

 following conclusions from it : 



First. That it is impossible to protect large and tall trees 

 from these beetles, when, as in this instance, these are issuing 

 in large quantities from the ground immediately under and 

 around the trees. 



Secondly. It confirms the fact that these insects, as do so 

 many other species, show a predilection for newly transplanted 

 trees, in which the growth is less vigorous and the foliage 

 more tender than it is in healthy forest trees. 



Thirdly. My place is well isolated from other forest trees, 

 the nearest woods being nearly half a mile away, with no other 

 cultivated trees of consequence in the immediate vicinity. It 

 occurred to me, therefore, that my trees suffered from a con 

 centration of the beetles from other parts of the neighborhood 

 on to these isolated trees, but I became convinced that such 

 was not the case, but that they all came from the ground in 

 the immediate vicinity. This conclusion was emphasized by 

 the fact that another large oak not two hundred feet away, 

 but on the east side of the house, and in ground from which no 

 beetles issued, was scarcely touched. The practical inference 

 is that if we can keep the ground in the immediate vicinity of 

 our trees free from the larvae, little injury will be suffered 

 from the beetles. 



The injury was not done through devouring of the leaves, 

 but almost entirely through the gnawing of the petiole near 

 the base or junction with the twig, the ground being covered 

 each morning with fresh leaves, 95 per cent, of which had 

 hardly been eaten at all. This preference for the gnawing of 

 the petiole is, so far as I am aware, a new experience, and may 

 be one of the habits peculiar to hirticula. It is an interesting 

 point, which, I regret, time did not permit me to solve satis 

 factorily, whether the same beetles re-enter the ground and 

 re- visit the tree day after day, or whether, on the contrary, 

 they are short-lived, and, after their first nocturnal havoc, 

 pair and re-enter the ground only to propagate. The ap 

 pearance of fresh holes daily would indicate the latter alter 

 native, and I am inclined to believe that the injury was done 

 by a succession of beetles, and also by a succession of species, 

 as it continued for the period of nearly a month, gradually 

 diminishing, however, and being worst during the first few 

 nights and especially in warm and calm weather. 



