1974 ] 
Cooper — Boreus 
109 
yellows, the moveable mandibles become testaceous to their bases, the 
eyes brown, yet with the three contrasting black nodes at their caudal 
margins distinct, and ocelli purplish, the malpighian tubules brown, 
and the bristles amber-brown. Within two weeks the eyes have be- 
come black, the three pigment nodes are still discernible, the ocelli 
are dark sepia, and the malpighian tubules are a dark purplish-brown. 
At five weeks the jaws and body are still moveable, but the pupal- 
adult apolysis has occurred. It is interesting that in the pharate adult 
female, the heavy black fixed setae of the gonapophyses attenuate 
near their midpoints; their threadlike prolongations (which are lost 
at ecdysis) connect with the corresponding setae of the pupal cuticle 
(fig- 3 J)- The pharate adult stage, during which the entire body, 
wings and legs of the imago darken, may last from ten days to three 
weeks. The pupal to adult ecdysis thus takes place (in the labora- 
tory) from a month and a half to nearly two months after the onset 
of pupation. Unlike B. hyemalis (Withycomb 1922, Fraser 1943, 
Striibing 1950) and B. westwoodi (Brauer 1857, 1863), in which 
the newly eelosed adult requires from a number of days to as much 
as a week to reach full color, but like B. brumalis (Williams 1916), 
B. notoperates is fully colored within a half day following eclosion. 
Just how long the true pupal and adult stages last in other Boreus 
is not known. Until Hinton (1971, 1973) straightened out the 
matter, and called attention to it, the importance of dating the stages 
from their apolyses, rather than from their ecdyses, had not been 
appreciated. Striibing (1950, 1958) gives a duration for the “pupa” 
of B. hy emails (as from) 40 to 59 days. 
Habitat 
The larvae and pupae of B. notoperates are found in the sods of 
mosses growing on diorite boulders from moderate (2 ft. dia.) to 
gigantic size. The immature stages occur in a very scattered distribu- 
tion, and I have not been able to forecast, when the moss is of an 
appropriate species, whether or not a given moss-covered boulder 
will be found to be inhabited by Boreus. Ordinarily specimens are 
few amid the moss of a given boulder but, when found, tend to be 
clustered. 
Initially I was unable to find immatures in the dry summer 
months. Because the mosses and their sods are very compact, desic- 
cated and crumbly at that time, and frequently at a. temperature 
(when sunned) of 30° ! C or more, it seemed likely that, following 
