POPLAR BORERS. 435 



INSECTS INJURIOUS TO THE POPLAR. 



AFFECTING THE TRUNK. 



1. The roPLAR borek. • 



Saperda calcarata Say. 



Order Coleoptera ; family Cerambycid.e. 



Ofteu destroying the Lombardy poplar, a yellowisli-white grub, nearly 2 inches 

 long, and changing to a gray longicorn beetle, irregularly striped with yellow ocher, 

 the wing-covers ending in a sharp point, flying in August and September. 



Harris states that this borer, with the grubs of the broad-neckecl 

 Priouus, almost destroyed the Lombardy poplars in his viciuity (Cam- 

 bridge, Mass.), and that it also lives in the trunks of the native poplar. 

 The beetles rest on the trunks and branches of various kinds of poplars 

 in August and September, and also fly by night, sometimes entering 

 the open windows in the evening. According to Riley this borer is 

 universally destructive to the cottonwood in the Western States. 



This borer has been destructive to poplar trees on the shores of Casco 

 Bay, especially at the head of the bay west of Harpswell Neck, where 

 my attention was first called to its work by ex-Governor J. L. Chamber- 

 lain, on whose estate at New Wharf a number of trees had died. The 

 trees in August, 1884, were seen to show unmistakable signs of disease 

 by the leaves curling and withering. The presence of the larva within 

 is easily detected by the masses of castings resembling sawdust, which 

 are thrown out of the holes and fall down the trunk to the ground. 



Upon cutting down the trees and splitting them open, not only the 

 full grown larva, or grub, but also one or two pup.T and several beetles 

 were found, the latter ready to issue from their holes. As many as 

 eight or ten larvse were found mining in a portion of a poplar trunk 10 

 inches long and 5 inches in diameter. 



The wood was perforated in all directions, running under the bark 

 part of the way and sinking in various directions into the wood, some 

 of them extending side by side along the heart of the tree. The longer 

 mines are about a foot in length, and about a centimeter or four-tenths 

 of, and at times half, an inch in diameter. Part of the mine is more or 

 less stuffed with long, slender chips gnawed off" by the larva. Mr. 

 Eeed, of Scottsville, N. Y., writes to the American Entomologist 

 (iii, p. 181) that this borer (identified by Professor Kiley) " destroyed two 

 fine trees upon my lawn of the native poplar, or, as it is sometimes 

 called, the trembling aspen. They perforate the trunk midway up 

 amongst the branches, when the top dies or is broken off by the wind." 



lJ>e larva. — About 2 inches long ; the body very thick, rather larger before than 

 behind ; the segments full and rounded. The first segment broad, sloping obliquely 

 downward to the head. On the upper side of the broad segment (pro thoracic) con- 



