GRAPEVINE LOOPER. 11 
tends its long body to secure a foothold as far forward as possible 
and then looping the body upward brings forward its prolegs at the 
anal end of the body to secure footing immediately behind the 
thoracic legs. Among the earlier stages locomotion is very delib- 
erate. The young larva precedes each forward extension of the 
body by raising the anterior part and swinging it in one direction or 
another as if to determine where the next step may safely be taken. 
In newly-hatched larvae this preliminary movement is greatly exag- 
gerated, and when a number of them migrate simultaneously along a 
cane they present a very ludicrous appearance, vigorously waving 
their long threadlike bodies to and fro before each looping movement. 
The prolegs are the locomotor appendages most depended upon, 
and when the larva is stationary the thoracic legs are used but little. 
So muscular are the prolegs that one has difficulty in loosening their 
grasp upon a leaf-stem without causing injury to the larva itself. 
The larva may be made to fall if surprised when feeding, and when 
this is done, it seldom catches itself by a thread of silk as do the 
cankerworms. 
When at rest or disturbed the older larvae, in common with others 
of the group, have the habit of holding the body rigidly at an angle 
to the cane or stem on which they happen to be situated, depending 
entirely upon the prolegs for maintaining their hold. (PI. II.) 
When in this position a larva may be mistaken for a grape tendril 
or leaf-stem, so that the habit is supposed to have some protective 
value. This habit is less characteristic of the younger larvae, which 
when alarmed usually hold their body in a curved position instead of 
straight. 
The dependence of the grapevine looper upon its prolegs for footing 
has modified its feeding habits, particularly in the earlier stages. 
Usually it grasps the edge of the leaf with its prolegs and extends its 
body over the upper surface toward the center of the leaf, eating the 
upper epidermis and parenchyma. As a result of this feeding habit 
a leaf attacked by one of these larvae is marked by a series of whitish 
patches on the upper surface extending around the edge and about 
the same distance within. (PI. Ill, B.) This characteristic location 
of the feeding marks readily distinguishes the work of this larva from 
that of any other pest of the grape with which the writer is familiar. 
However, if their position on the leaf is not taken into consideration 
the marks left by the small larvae of the first instar may be mistaken 
for those of flea-beetles, while the large patches left by large larvae 
might be mistaken for those of other grape-feeding Lepidoptera, as 
the eight-spotted forester (Alypia octomaculata Fab.) or beautiful 
wood nymph (Euthisanotia grata Fab.). 
Larvae of the fifth instar, and often of the fourth, feed at the edge 
of the leaf, stripping all but the stems and larger veins. (PI. Ill, A.) 
