35 



but it was found this summer attacking apparently sound timber, and proving a 

 destructive enemy. The outbreaks located were not large, but proved that this 

 species may become a very serious enemy to the Coast spruce. Reports were 

 received of extensive bark-beetle injury to spruce farther up the coast and on 

 Queen Charlotte islands. It is possible that this beetle is the primary cause of 

 the injury, but it was impossible to make a personal investigation this season. 



The adult beetle is black, stout, from seven to nine thirty-seconds of an inch 

 in length, distinctly hairy, with long hairs extending nearly to the base of the 

 wing-covers; the pronotum wider than long, with the sides strongly narrowed 

 in front ; the wing-covers with impressed striae of rather small punctures, and the 

 interspaces of the dorsal portion rough. 



The larvae are stout whitish grubs, about as long as the adults, with powerful 

 jaws, and are found working in the inner bark of the Sitka spruce. 



Habits. The pairs of beetles enter the bark during spring and summer 

 and excavate elongate, rather straight tunnels upwards from the entrance hole 

 between the bark and wood. The eggs are laid along the sides of the tunnel 

 in irregular rows or groups of varying numbers. The tunnel side is grooved 

 for their reception, and they are usually enclosed by a continuous layer of 

 boring-dust. The rows of eggs are frequently more or less distinctly alternately 

 arranged. The eggs are frequently scattered rather sparsely along the tunnel 

 side at first, and later, more eggs may be laid along the same portion of the 

 tunnel, between those first deposited. In a specimen before me the egg-tunnel 

 is about 4.5 mm. wide, with the egg-groove 1 mm. deep. There are tunnels 

 of larvae two-thirds grown arising from one portion, and along the same side, 

 between the origins of these tunnels, are numerous eggs, singly and in groups. 

 The larvae when hatched bore through the inner bark away from the egg-tunnel. 

 Their mines are separate and distinct for a half inch or less, and then interlace 

 irregularly so that the inner bark is often entirely reduced to powder. After 

 the larvae are two-thirds grown their mines tend to become distinct, and separate 

 tunnels are excavated up or down the trunk. The pupal period is passed in 

 the enlarged ends of the larval mines, either in the inner bark or in the middle 

 layers. 



When standing trees are attacked, the first broods apparently enter the 

 thinner bark of the middle trunk, and those appearing later extend the infes- 

 tation to tne base of the tree and even upon the larger roots. 



A few cocoons of a hymenopterous parasite were fouad in the ends of larval 

 tunnels. 



Seasonal History. The early history of the species was not completely 

 studied; but, in Oregon, Dr. Hopkins finds that the adults become active in 

 April, emerge from the bark and attack fresh trees during May and June, 

 and probably later. The principal period of larval development, in Oregon, 

 is during June, July and August. The larvae transform to pupae from the last 

 of July onwards, but maialy during August and September. The pupae trans- 

 form to adults from mid-August to the end of the season. Eggs and young 

 larvae were common in September, and may have represented a second brood, 

 or may have been from a second batch of eggs laid by the parent adults. 



The above history appears to hold for the southern half of British Columbia, 

 except that a larger percentage of the beetles emerge and start their tunnels 

 in fresh bark during August. By the middle of September, in the latitude of 

 Vancouver, some tunnels contained only young adults, some only pupae and 

 large larvae, and many contained only small larvae and eggs, or eggs alone. 

 It is apparent that tunnels are started by over-wintered young adults during 

 early summer and throughout August. The majority of the tunnels started 

 in September were cut by black, fully-matured adults, without doubt the parent 

 adults of the early broods. In tunnels started during August and September, 

 egg-laying continues until October. We obtained no evidence this season of 

 any considerable partial second brood. In the older tunnels the broods trans- 

 form to adults quite completely before winter. The winter is passed as young 

 adults, larvae and old parent adults. 



