848 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
in the pupil state beyond the 14th of August. The moths are subject 
to great variation, the details of which are given in the description. 
In their color they are assimilated to the moss-covered bark of the 
larger branches of the trees on which they rest 
The caterpillars are sometimes preyed upon by ichneumons, two 
small Iclineuinonida' having been bred from pupa' in confinement. No 
Chaloid parasites have yet been observed to prey upon this species. 
Should the worms attack shade or ornamental firs and spruces, they 
can be subdued by spraying and striking the branches and shoots so as 
to dislodge the worms. 
Larva before the last moll. — Bodv pale green, nearly of the color of the fresh leaves, 
with the head and cervical or prothoracic shield black. Length, 10-ll inm . 
Full-tjroun larva. — Body pale pea-green, moderately thick, gradually tapering from 
the middle to the end of the body. Head of the usual shape, somewhat bilobed, not 
BO wide as the body : dull reddish amber, or greenish-yellow amber-colored in front ; 
partly brownish-black behind and on the sides, the black forming two patches on 
the vertex. Prothoracic or cervical shield black ou a greenish ground ; varying to 
greenish-amber edged behind with blackish ; sutures and lateral ridge slightly tinged 
with yellowish. On the body-segments the piliferous warts green, not distinct ; 
arranged as usual in a trapezoid. Thoracic legs greenish amber-colored, first pair 
larger and darker than the others ; abdominal legs pale green, concolorous with the 
body. Length, 12-14 mm . 
Pupa. — Body rather slender, the double rows of dorsal spines as usual, but the 
spines are smaller and not so sharp as usual. End of the abdomen broad, square, and 
much flattened vertically, with a small down-curved spine on each side ; on the 
square edge of the tip are from four to six slender, small, curved, stitf bristles. There 
are two similar bristles on the under side within the edge of the square tip. Length, 
s-9 ,n »>. 
Moth. — Head white or subocherous ; palpi dull gray, with white scales. Thorax 
either white and black or reddish ocherous with white scales. Fore wings with the 
basal third either black, gray, or snow white ; usually dark gray : on the outer edge 
of the dark portion are two groups of sharply raised scales. Beyond is an irregular 
white baud, the white sometimes obscured by gray scales ; this baud is very irregu- 
lar in width, being narrow on the costa, widening towards the middle of the wing: 
it is indented on the inner side at the second tuft of raised scales ; where the band is 
widest, viz, on the outer edge behind the middle of the wing, is a deep sinus, very 
distinct in those specimens where the band is white; on each side of the mouth of 
the sinus is a sharp tuft of raised black scales, aud within (one near the costa) are 
the smaller tufts. In those specimens in which the rest of the wing is whitish there 
is a large triangular dark spot, with the base resting on the costa ; usually, however, 
the outer third of the wing is dusky or clear gray, with dark specks and clouds, and 
the triangular patch is obscured. Sometimes when the wing is clear gray the veins 
on the outer third are hardly clouded with a darker shade of gray. Hind wings and 
abdomen slate gray. Expanse of wings, 12-15 mm . 
This is a very variable moth, but the four or five raised tufts are nearly always 
present. Some striking varieties are here noted : 
(a) Fore wings gray, with a broad whitish-gray band just before the middle of the 
wing: the large dark triangular spot not present. 
(h) The outer third of the wing concolorous with the band, thus leaving a large 
distinct triangular spot. 
(c) Fore wings snow white at base, with a snow-white band near the base, in the 
outer edge of which the sinus is very distinct : the outer third of the wing is either 
white or blackish. 
