266 
LEPIDOPTEEA. 
constituted the appropriate food of these insects, before the 
exotic species furnished them with a greater variety and 
abundance. 
Their injury to these cultivated plants is by no means 
inconsiderable ; they not only eat the leaves, but are par- 
ticularly fond of the blossoms and young seeds. I have 
taken twenty caterpillars on one plant of parsley, which 
was going to seed. The eggs laid in July and August are 
hatched soon afterwards, and the caterpillars come to their 
growth towards the end of September, or the beginning of 
October ; they then suspend themselves, become chrysalids, 
in which state they remain during the winter, and are not 
transformed to butterflies till the last of May or the begin- 
ning of June in the following year. 
I know of no method so effectual for destroying these 
caterpillars as gathering them by hand and crushing them. 
An expert person will readily detect them by their ravages 
on the plants which they inhabit ; and a few minutes de- 
voted, every day or two, to a careful search in the garden, 
during the season of their depredations, will suffice to re- 
move them entirely. 
There is another butterfly which hears a close resemblance 
to the female of the Asterias butterfly, and is nearly of the 
same size ; but the blue spots on the hind wings are much 
larger, and cover nearly one third of the surface ; the yel- 
low spots around the margin are larger and paler ; the eye- 
like spot near the hind angle has not a black centre, and 
there is a large orange-colored spot near the middle of the 
front margin of the same wings. This species is the Troilus 
butterfly, or Papilio Troilus of Linnaeus. 
The caterpillar is entirely different from that of the As- 
terias butterfly. It lives on the leaves of the sassafras-tree, 
upon the upper surface of which it spins a little web, and 
folds over the sides of the leaf so as to form a furrow or 
case, in which it resides. The fore part of its body is large 
and swollen, and it tapers thence to the tail. When first 
