INSECTS AFFECTING PARK AND WOODLAND TREES 347 



the bark. They are not quite so large as the beetle, having a smaller 



transverse diameter and tapering very much to 



the posterior extremity. Two or three of the 

 abdominal segments usually project beyond the 

 tip of the wing covers. As the pupa advances 

 in age, the white becomes yellowish and the 

 mandibles may be a dark brown. 



The full crown larva is a brown headed 



o r lg. 68 Declivity of I o m 1 c u s c a 1 1 1- 



grub about 3/ l6 inch long when normally extended. grapl,l,s (m*^ "lustration) 

 It body is rather stout, usually slightly curled and there is frequently a 

 considerable thickening in the thoracic segments. Portions of the mandi- 

 bles and the borders of adjacent sutures are dark brown. 



The galleries of this borer are very characteristic and frequently afford 

 one of the readiest means of recognizing the insect. The exterior signs of 

 its presence may be limited to numerous circular holes about 1 g inch in 

 diameter or very few of these may be found. This latter occurs in cases 

 where the beetles have entered the bark in larp;e numbers but have not 

 emerged. The entrance is usually effected under a projecting scale of bark 

 and is therefore not conspicuous, while many of the exit holes [pi. 56, 

 fig. 1] occur on the prominent ridges and are therefore very easily 

 detected. This species under certain conditions attacks living tissues and 

 in that event the presence of the borers is indicated by brownish or whitish 

 pitch tubes which may be nearly y 2 inch in diameter and almost that in 

 hight. One of these structures is represented [pi. 54, fig. 4] and a close 

 examination would show that it was built up with particles of pitch from 

 the burrows. Plate 54, figure 2, shows a pine trunk with a number of 

 pitch tubes indicating that the tree was alive when attacked. These pitch 

 tubes are located, as a rule, over the entrance or nuptial chamber, from 

 which the females make their galleries, usually following along the grain 

 of the bark. 



Plate 54, figure 3, shows one of these nuptial chambers on the inner 

 side of the bark and represents the seven female galleries, three extending 



