82 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
tubercles, with bristles similar to those in the preceding instar, 
0.2-0.25 mm. in length, with the black on the apices, joints, and bulbs 
at the base more pronounced, causing the tubercles to appear black to 
the naked eye. ‘All the segments laterally, and dorsum of the an- 
terior and posterior segments with long, segmented, whitish hairs 
variable in length. Thoracic feet small, pointed, dilute-brown, 
darker at the tip; abdominal feet larger, apex with a circlet of black 
bristles, all the feet similar in color to the rest of the body. Length, 
3.54.5 mm.; width of head, 0.666 mm. (nearly constant). 
Fourth instar.—Body sulphur-yellow, head retractile, dilute-brown, 
darker on exposed portion, mandibles and eyes brownish-black. 
Head when viewed from above oval- 
pyramidal in form. Tubercular areas 
very prominent now to naked eye, 
appearing as black, bristly, wartlike 
patches, this appearance due to the 
black tips of the whitish, jointed bris- 
tles; joints and bulbs at base of bristles 
blackish. Tubercular areas on dorsum 
of segments 7, 8, 9, and more especially 
7 and 9, fainter to naked eye than on 
other segments, as the bristles are not 
so heavily tipped with black nor are 
the joints black. Dorsum of anterior 
and posterior segments and all segments 
laterally with long, whitish, segmented 
hairs of variable length. Thoracic and 
abdominal feet yellowish, longer, but 
Fic. 14.—The grape-leaf skeleton- - é : 
iner. (Herrisina americana): marked the same asan the thicd simaeare 
Full-grown larva, at left; a, lat- Length, 7-8 mm.; width of head, 1.05— 
su gn liens hee Se ote eOG mma (nearly constant). 
of posterior segments. En- Fifth instar.—Body deep sulphur- 
aie has ace yellow, head retractile, dilute-brown, 
darker on exposed portion, mandibles and eyes brownish-black. 
Shape of head similar to that in the fourth instar. Tubercular 
areas now very prominent to naked eye and appearing as black, 
bristly, wartlike patches. Bristles under 3-inch objective same as in 
the fourth instar, but more distinct and longer (0.20-0.33) mm. in 
length). Tubercular areas distinct on all segments, and to naked eye 
with a shght opaque-bluish cast. Dorsum of anterior and posterior 
segments, and all segments laterally, with long, segmented, whitish 
hairs, longer than in fourth instar. Thoracic feet yellow, tipped with 
black; abdominal feet yellow, with a terminal circle of black bristles. 
Length, 8-10 mm.; width of head, 1.15-1.45 mm. (variable). 
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