322 
THE STUDY OF INSECTS. 
are much lighter in texture, being extended over all of the 
leaves fed upon by the colony. 
The Isabella Tiger-moth, Pyrrharctia Isabella (Pyr-rharc'- 
ti-a is-a-bel'la).—“ Hurrying along like a caterpillar in the 
fall” is a common saying among country people in New 
England, and probably had its origin in observations made 
upon the larva of the Isabella Tiger-moth. This is the 
evenly clipped, furry caterpillar, reddish brown in the 
middle and black at either end, which is seen so commonly 
in the autumn and early spring (Fig. 394). Its evident haste 
to get somewhere, in the 
autumn, is almost painful to 
witness. A nervous anxiety 
is apparent in every undulat- 
Fic. 394. Pyrrharctia ixabtlla, larva. j n g movement of its body J 
and frequently its shining black head is raised high in the 
air, and moved from side to side, while it gets its bearings. 
Occasionally after such an observation it evidently finds it 
is mistaken, and turns sharply and hastens along faster than 
ever in another direction. So far as we can judge, its ex¬ 
citement comes from a sudden fear that winter will over¬ 
take it before it can find a cosy, protected corner in which 
to pass its winter sleep. In the spring it comes forth again, 
and after feeding for a time makes a blackish-brown cocoon 
composed largely of its hair. The adult is of a dull grayish 
tawny-yellow, with a few black dots on the wings, and fre- 
quently with the hinder pair tinged with orange-red. On 
the middle of the back of the abdomen there is a row of 
about six black dots, and on each side of the body a similar 
row of dots. 
The Yellow-bear, Spilosoma virginica (Spil-o-so'ma vir- 
gin'i-ca).—The larva of this species is one of the most com¬ 
mon hairy caterpillars found feeding on herbaceous plants. 
It was named by Harris the Yellow-bear on account of the 
long yellow hairs with which the body is clothed. These 
hairs are uneven in length, some scattered ones being twice 
