THE PINE BOEER OR "SAWYER." 691 



The egg (Fig. 228, a) is very large, ovo-cyliudrical, well-rouuded, but 

 but tapering somewhat at each end, of a dirty- white color, and in 

 length is 4^'"'". 



On visiting the tree a week later and removing a portion of the bark 

 and examining it, September Q-8, the eggs had in some cases hatched 

 and the larvae had begun to descend slightly into the bark. On hatch- 

 ing they begin at once to gnaw a mine, throwing their castings out 

 through the gash originally made by the female, so that it was easy to 

 ascertain without disturbing the bark whether the eggs had hatched or 

 not. The larvse indififereutly lie with either side, dorsal or ventral, pre- 

 sented outwards. Three days after (September 12) several had bored 

 through the pieces of bark, making the usual flattened oval hole, but 

 probably in nature the larva remains hidden in the bark through the 

 winter, not beginning to penetrate the wood until the following spring. 



The length of the larva when freshly hatched was 5-6™'", and the 

 body was rather stouter than in the fully-grown larva. (Fig. 228, b.) 



How many eggs are laid by the female is not known, but, probably, 

 judging by their large size, comparatively few. 



Another female was found on the same tree. Over a hundred gashes 

 had been made on the western side of this fir tree over a space 4 feet 

 long; the gashes were so fresh that they must have been made on that 

 and the previous days. They were quite conspicuous, and could, after 

 one had become familiar with their appearance, be detected at the dis- 

 tance of 5 or 6 feet from the tree. I suspect that the sexes couple 

 frequently during the operation of egg-laying, as the male was stand- 

 ing so near his mate with his antennie outstretched and intently 

 watching the female while at work. The males are also probably 

 polygamous. 



The industry of the female is well shown by the number of gashes 

 made (Fig. 229 a, b), some of which did not, however, contain any eggs. 

 In the space of a square inch there were three gashes, while in the region 

 where they were thickest forty were counted in half a square foot. Of 

 course when they hatch all do not live to pass through their transforma- 

 tion. Whether the woodpeckers seek for and discover the larvse 

 ensconced in the bark is doubtful, and yet it would be easy for them or 

 other birds to pick the grubs out of their hiding places. So far as my 

 observations have gone the holes made by the woodpeckers in forest 

 trees are for the purpose of getting at the inner bark rather than for 

 insects. But a careful examination of woodpeckers shot in coniferous 

 forests would throw light on this subject. 



In regions where the white pine grows it is infested by the Mono- 

 hammus. The spruce is also often infested, but I have not seen clear 

 cases where either of those trees have been killed outright by this de- 

 structive borer. But during the past summer (1885) I have seen on the 

 islands in Casco Bay and taken out the full grown larvae from at least 

 six or seven living firs, which must have been killed by the attack 



