SPAN-WORMS. 205 
inch and a quarter to fully twoinches. It is shown in two 
forms in Fig. 199. 
The body and wings of this insect are ochreous-yellow, 
often pale in the middle and basal portions. The fore-wings 
are crossed by three rusty-brown curved lines, the outer 
strongly dentate in the middle; beyond this is a subterminal 
faint line, not always distinct. The hind-wings are paler 
than the fore-wings, clear, usually without lines except in 
the outer third near the anal angle, where there is a faint 
brown line edged on the outside with white. At the anal 
angle is a dark spot composed of two brown lines, with 
violet-brown between them. The moths vary greatly in 
intensity of colors and markings, some being almost plain 
yellowish-brown with but very few indistinct bands, of 
which the outer dentated one is always visible. 
The moths deposit their eggs upon the leaves of the 
grape-vine, from which the young caterpillars hatch a few 
days later, reaching their full size in about four weeks. 
They are then about an inch and a quarter long, have a dull 
reddish-brown head, a yellowish- 
green body, with a few small whit- 
ish dots on each segment. Oneach 
side of the second segment is a 
small reddish spot and on the third 
a larger one of a darker shade; on 
this latter segment there is a fold 
in the skin, which makes the spot 
appear as a brown prominence. 
On the terminal segment are two 
Fig. 199.— Petrophora diver- : P “ 
silineata Hub. short greenish spines, which 
extend backwards; the surface of the body is wrinkled; 
the under surface is reddish, with a central: reddish ‘dine 
bordered with white, which is margined with dull red. 
These caterpillars are also very variable in color, but are 
always well protected by blending with the surroundings; 
when disturbed they straighten themselves, remaining per- 
