44 THE CANADIAN ENTOMOLOGIST. 



the insects if they are left undisturbed in their silken tunnels ; but, if these 

 are broken by constant sweeping, and the caterpillars are left exposed, 

 cold will certainly injure them. Moths and caterpillars placed in a glass 

 bottle, and exposed to a temperature of five degrees above zero (Fah.), 

 were all severely crippled, and did not recover. The above facts suggest 

 the advisability of occasionally opening mills, which are supposed to be 

 infested, so that the cold of winter may penetrate. If the moths are seen 

 about in spring, fumigating with sulphur at short interval must be practised. 

 Old sacks received from outside sources should be carefully examined, as 

 these would probable be the most frequent means of carrying the pest 

 from one mill to another. It is probable that this insect passes the winter 

 in the caterpillar state, in which it is more or less active, according to 

 the temperature. 



SOME NEW COLORADO MOTHS. 



BY G. H. FRENCH, CARBONDALE, ILL. 



Cossus Brucei, nov. spec. 



Expanse, male 2.50, female 3.00 inches. 



Ground color, very pale gray, almost white, no dusky shading over the 

 wing. Fore wings crossed by a great number of fine black lines. In the 

 male none of these form reticulations except a few along the basal half of 

 the internal vein and near the outer margin. The female has a few more 

 of the reticulations in the outer third of the wing. On the male one line 

 more prominent than the rest crosses the wing through the middle from 

 the costa to the posterior margin at the origin of the fourth median vein, 

 forming a straight line. On the female this line follows the fourth median 

 vein about a tenth of an inch, and then goes in a straight line obliquely to 

 the margin, and is not so heavy as in the male. Both sexes have a sub- 

 terminal line not quite so prominent as the median, from near the apex 

 to the posterior angle, bifid on costa, nearly straight in the male, slightly 

 curved outv\ardly in the female, reaching the angle in a fine line. Veins 

 dark only as denuded. Hind wings, with a space at the base and along 



