117 



Distribution. Alaska, the Yukon, British Columbia, and northern and 

 western Alberta; extending into the Western States. 



Economic importance. Usually secondary, but at times evidently a 

 primary enemy. 



Ips oregoni Eichh.; Berl. Ent. Zeit., 274, 1868; Rat. Tomic. 150, 1878. 



Rather larger and stouter than the typical pini; length usually about 

 4 5 mm. ; the pronotum as wide as long with the sides straight and parallel, 

 broadly rounded in front, finely punctured behind; the elytral strise hardly 

 impressed, the second interspace with a row of punctures on the caudal 

 half making the sutural strise evidently widened behind; the sides of the 

 elytra rather coarsely punctured. Secondary sexual characters as in pini 

 Say. There are variations in southern British Columbia that intergrade 

 with interpunctus, and others that can hardly be distinguished from pini 

 Say. 



Host tree. Western Yellow Pine. 



Distribution. In British Columbia probably throughout the range of 

 its host; Western United States. 



Economic importance. Usually a secondary enemy in British Columbia, 

 in slashings and weakened trees, but evidently at times an important 

 primary enemy. 



The type of Ips rectus Lee., Proc. Am. Phil. Soc., 15: 363, 365, 1876, 

 is probably an abraded specimen of Ips oregoni Eichh. A similar indi- 

 vidual condition is commonly found in species of the genus. 



Ips perroti Sw.; Can. Ent., 47: 356, 1915, 2 figs. 



Length, 4 mm.; the declivital teeth of the male larger than in the 

 female, the 3rd stoutest and capitate. This species differs from tridens, 

 borealis and interruptus by the characters of the front, which lie between 

 the much sparser granulation of one sex of borealis and the extremely 

 dense granulation of interruptus; from borealis in the longer, much more 

 finely punctured pronotum, more sparsely punctured elytral interspaces 

 and distinctly much more strongly developed declivital armature; from 

 interruptus in the usually much smaller size and more slender form, finer 

 and sparser punctuation, the much more abrupt declivity with strongly 

 marked sexual variation, and the fewer and smaller granules on the first 

 and second interspaces. 



Host tree. Red Pine. 



Distribution. Isle Perrot, Que. Rare. 



Ips borealis Swaine; Can. Ent., 45: 213, 1911. 



Length, 3 25 mm. to 4 mm. ; more slender than interruptus; the female 

 with the front and vertex of the head convex, remarkably smooth and 

 polished, with a few extremely minute punctures, the anterior portion of the 

 front and the region about the eyes extremely minutely, more closely punc- 

 tured and bearing minute inconspicuous hairs; with a very faint, broad, trans- 

 verse impression between the eyes; the epistoma faintly depressed; the first 

 two sutures of the antennal club broadly bisinuate, the second more strongly; 

 the pronotum with the caudal half shining, coarsely, deeply, roughly, 

 rather sparsely and irregularly punctured; the elytral striae faintly impressed, 

 excepting the sutural striae which are wide, deep and broader behind; the 

 strial punctures on the disc round, deep, moderate in size, not close; the 

 declivity with four teeth on each side, of the pini type, the third tooth 



