CATERPILLARS OF THE FIR. 865 
incised ; when at rest retracted partly under the projecting prothoracic segment. 
The last segment with a large triangular thick lateral flap. Two dorsal dull yellow- 
ish sinuous lines, separated by a narrow median reddish line. Body beneath with 
dull obscure sinuous, somewhat broken, coarse yellowish lines. On the last segment 
are two high sharp tubercles. Supra-anal plate rounded. Body roughly granulated. 
A light dull whitish yellow lateral stripe, extending down on the anal legs. Length, 
15 mm . 
Some of the caterpillars occurring on the fir have a smoother body, less wrinkled, 
and the head is not red, but pale green. There is a conspicuous white spiracular 
line; and two subdorsal pale yellowish indistinct lines; the sutures are distinctly 
yellow. 
Pupa.— Of the usual form, rather slender, brown, the abdomen bright brick-red 
above between the wing-covers ; the end horn-brown and mottled ; there is a blackish 
dorsal line and a dark stripe along the antennae and veins of the wing, the branches 
being spotted with black. In another specimen the wiug-covers were red and the 
body, including the abdomen, horn-colored ; the terminal spine is short, moderately 
stout, with eight unequal curved slender spinules. Length, 9 to 10 mm . 
Moth. — Six specimens, two of them males, issued from the chrysalids in the breeding 
box, in Providence, between April 20 and 25. They were all of uniform size, the 
wings expanding about 25 mm . They differed but slightly from A. mimosaria, though 
much smaller ; compared with one of the latter the hind wings are more angulated, 
while the outer white line on the same wings is less bent in the middle. The lines 
on the fore wings are as in A. mimosaria, but vary in distance apart. The head and 
abdomen are marked as in A. mimosaria ; the male hind tibiae are as in that species. 
It differs decidedly from the two other species of its size, A. approximaria and latiaria. 
14. Semiothisa bisignata (Walker). 
(Larva, Plate xxxn; fig. 1, la-lh.) 
Though more common on the pine, the figures on Plate xxxn were 
drawn from a specimen collected on the fir, at Brunswick, Me., August 
27-30. For details see Explanations of the Plates. 
It also occurred on the pitch pine July 15 to August 3, at Bruns- 
wick, Maine. 
15. The fir-needle inch-worm. 
Eupithecia luteata Pack. 
Order Lepidoptera ; family Phal.enidje. 
(Larva, Plate x; fig. 4.) 
This is a common caterpillar on evergreen trees, excepting the pine, 
and was described in Bulletin 7, U. S. Entomological Commission, p. 237; 
No. 8 also, p. 206, No. 83. The caterpillar is rather flat, the surface 
granulated, the body reddish and bearing a remarkable resemblance to 
a red, dead fir-leaf. It tarns to a chrysalis late in August and early in 
September in Maine, and the moth appears the following May and June. 
This is one of the most remarkable cases of mimicry yet noticed among 
those feeding on coniferous trees. Often on beating them into an um- 
brella, which I used in collecting caterpillars, have I hesitated to pick 
5 ent 55 
