March, 1898.] Dyar : Life-Histories of N. Y. Slug Caterpillars. 1 
Description of the Several Stages in Detail. 
Pgg- —Elliptical, flat, 1.0X.6X.1 mm.; whitish transparent, 
colorless. Reticulations distinct, irregularly quadrangular, narrow, 
raised. In the bright light with the green leaf behind they appear as 
narrow black lines, bordered by a bright area on both sides, the flat 
cell-areas dusky grayish. They hatch in 10 or n days. 
Stage I .—Just like P. geminata, the spines arranged the same 
(Plate I, fig. i); all short with irregularly knobbed tips. Branches of the 
sub-dorsal spines just distinguishable as little protuberances. Elliptical, 
rounded, dorsum and sides grooved, subventral space small. Ridges 
smooth, setae colorless. Skin shining, smooth, colorless, transparent; 
food green ; head concolorous. Length, .8-1.4 mm. 
Stage II. —Obscure, not shining, pale whitish, just tinted with green, 
translucent. Elongate elliptical, narrow, the tail narrowly quadrate. 
Ridges slight, non-tubercular, two setae on subdorsal ridge, one on lat¬ 
eral ridge, normal, except only one on the middle row of joint 4; black 
tipped and with stout expanded bases. Skin granules small, sparse, low 
conic, clear, alike everywhere, not produced on the ridges. The largest 
depressed spaces, (1) and (4), are indicated as slight hollows. Length, 
1.3-2.1 mm. 
Stage III .—Elongate elliptical, narrowing posteriorly, tail rounded, 
not produced. All frosted whitish, scarcely tinted with green. Setae 
distinct, sharp, black tipped, arising from slight tubercles on the subdor¬ 
sal ridge, distinct conic segmentary ones on the lateral ridge. All of 
skin surface and tubercles covered densely with small low conic clear 
granules, uniformly even over the obsolete depressed spaces, where they 
are scarcely thinner. The granules are very numerous, almost con¬ 
tiguous, but rounded, not appressed. (Plate I, fig. 5.) The shape is 
now unusually narrow, dorsal space not narrowing much to the ends. 
Very colorless, translucent, the blood only slightly green and no pig¬ 
ment present. Length, 1.8-3.0 mm. 
Stage IV. —Narrow, elongate, truncate before; tail produced, but 
tubercular like the ridges. Frosted whitish from the granules and, 
therefore, slightly opaque ; almost entirely without pigment, the blood 
visible pulsating, slightly green tinted. An obscure whitish dot under 
the subdorsal ridge at each intersegmental space, representing a sub¬ 
dorsal line. Setae short, black and distinct. Granules small, even, 
dense, but not quite contiguous, running uniformly over the whole sur¬ 
face; depressed spaces scarcely indicated anywhere. Length, 2.8-4.0 
mm. 
