208 NORTH AMERICAN INSECTS. 
erpillars proceeding from these eggs are very injurious to 
vegetation ; and it isnot uncommon to see more than twen- 
ty of them on a single stem of carrot or celery. These lar- 
ve are generally known under the name of Parsley worms, 
and may easily be destroyed. They are smooth-bodied, and 
of a bright-green color. These caterpillars may also be col- 
lected and raised without trouble, except that many of them 
are stung by ichneumon wasps, which deposit in each an 
ego, the maggot of which feeds on the flesh of the caterpil- 
lar without touching any vital part or preventing its trans- 
formation into a cocoon. After this metamorphosis the 
maggot consumes all that remains of the embryo butterfly, 
then goes through its own transformation, and, instead of 
the butterfly, comes out a perfect ichneumon wasp (Fig. 
67). 
The Tromvs (Papilio Troilus), Fig. 58, is another of 
these celebrated knights, named by Linneus after King 
Figure 53. 

The Troilus, 
