1911 



ENTOMOLOGICAL SOCIETY 



85 



'thick bark. From the nuptial chamber come off the winding, irregular egg- 

 j tunnels. The eggs are laid in groups of two to eight, in deep pockets along the 

 sides of the egg- tunnel. The borings of the larvse are very irregular and pene- 

 trate the bark in all directions. The larvae pupate in their tunnels in the bark, and 

 appeared through their exit holes early in July to start tunnels for a new brood. 

 Egg-laying for the second brood was well advanced in the bark of the stumps on 

 ;Ju]y 10th of this season. This species is common in our district in red and white 

 [pine. It works in the bark towards the base of dying trees; particularly it is found 

 I in stumps cut the preceding winter. I have never noticed it in healthy trees, al- 

 [ though it might injure them when no dying bark was available. The first brood 

 [was egg-laying in white pine at Ste. Anne's, the second week in May this year, and 

 jwlien first noticed in larch. May 24, the eggs were practically all laid. 



Dryocoetes autographvs was breeding in the bark of the larch stumps. Its 

 egg-tunnels are irregular, anastomosing, and when numerous rlifficult to follow. 



Fig. 7. 



O. materiarius. "Work in larcti wood.A. — w.s., wood 



surface; e.n., egg-uiche; d., a tunnel ending 



blindlj' behind a. In this tunnel the fungus 



develops rapidly. Eggs and larvae have 



been removed from the niches. B. — 



Two eggs in position in the 



niches. 



The eggs are laid side by side in shallow niches along the side of the egg- tunnel, 

 and packed in dust. The longer axis points away from the centre of the tree. 

 Frequently the eggs are sunken irregularly into the bark of the tunnel roof and 

 packed in dust. The larval galleries are very irregular, usually destroying the 

 bark. Both egg-tunnels and larval galleries are often entirely in the bark. There 

 are two broods each season with us. By July 10th this season the egg-tunnels were 

 about completed in the larch stumps, with the eggs practically all laid and many 

 larvae working into the bark. By the first of August these larvae had matured in 

 part and eggs were being laid in new tunnels from the sixth to the twentieth of 

 that month. This insect prefers dying and dead bark of pine, spruce and larch, 

 and works mostly at the base of the tree. It is not particularly injurious. A 

 smaller, undescribed species of Dryocoetes was working with autographus, and has 

 very similar habits. 



This completes the list of the true Bark-beetles found in those larches. There 

 was also present another scolytid — Gnathotrichus materiarius — one of the Ambrosia 



