6 
slender than the female, which has a rather broad pointed abdomen. 
The eyes of the male are contiguous on the top of the head, while those 
of the female (fig. 4, v) are quite widely separated. Little is known 
of the habits of the adults. Though carefully sought for, only one speci- 
men was taken in the field. This was flying in the sun in a little 
meadow at the edge of a forest. The species was described! from a 
single female taken at Cook’s Inlet, Alaska. ‘here is also a female 
from Yakutat, Alaska, in the U. 8S. National Museum Collection. 
HABITS OF THE LARVA. 
The larva is usually found in the wound (fig. 38, #), surrounded by the 
soft resin. The head and body lie in the inner part next to the sapwood, 
while the tail extends out through the bark and outer resin mass, with the 
spiracles opening into the air. The cambium, or growing layer, which is 
composed of soft, living, outer sapwood and inner bark, is bruised and 
torn by the mandibular hooks until quite a wound is made. This is 
enlarged as its occupant grows in size. The resin is pushed out of the 
entrance and forms an irregular, globular, reddish-gray mass on the 
outer bark (fig. 3, g, k, and fig. 4, m). 
Breathing through its tail and feeding on the sap and soft tissues of 
the tree, the larva lives in the wound until it becomes full-grown. This 
takes, in some cases at least, several years. Some larvee, from eggs 
laid, probably, in May, 1903, had not changed to adults in October, 
1904. All sizes of larvee are found at all seasons of the vear, but the 
adults during April and May only. The wounds (fig. 8, 7,7) show that 
as many as five successive layers of new growth may be eaten, although 
the usual number seems to be three. These facts seem to indicate that 
living representatives of several broods may be found at any time, and 
that the length of the larval stage is variable. It is probable that under 
unfavorable conditions it may be prolonged to four or five years, while 
if the conditions are favorable it may be shortened fo one year. 
Although the larva is usually found in the wound as described before, 
it sometimes moves around in the outer resin mass and even on the 
outer surface of the mass. In the spring the fully developed larva with- 
draws to the outer mass to pupate (fig. 3, J). 
The primary wound made by the barkbeetle through the bark remains 
the same size as the beetle leaves it, and the bark maggot occupies the 
chamber between the inner bark and wood. Both entrance and cham- 
ber are filled with resin. The completed wound (fig. 4, 0, p, q), there- 
fore, consists of the beetle burrow, which is about 0.08 inch in diame- 
ter, through the outer and inner bark to the inner chamber, which is 
one-half inch to 1 inch in diameter. The external resin mass is 0.6 
inch to 1 inch in diameter, and 0.4 to 0.6 inch in depth. 


1W. D. Hunter, Can. Ent., Vol. XXIX, p. 124, June, 1897. 
