INTRODUCTION. 
89 
Non v’ accorgete voi, che noi siam’ vermi 
Nati a formar 1’ angelica farfalla ?” * 
Lepidopterous insects, like most others of their 
class, are liable to be attacked by various parasitical 
assailants, which effect a lodgment in the interior of 
their bodies, the substance of which they speedily 
consume, and thereby destroy them in great num- 
bers. In none of their different stages are they ex- 
empt from these attacks, excepting perhaps in their 
winged state ; but they are particularly exposed to 
them when caterpillars. The parasites are hyme- 
nopterous flies belonging to the genus Ichneumon of 
Linnaeus ; and perhaps the most destructive are those 
minute kinds which compose the modern generic 
group named Microgaster. As an example of the 
latter, we have represented the species which de- 
stroys the caterpillar of the common Cabbage But- 
terfly : it is the Ichneumon glomeratus of Linn. 
(Plate II. fig. 8, greatly magnified.) The size is 
very diminutive, the largest specimen seldom ex- 
ceeding two lines in length. The general colour of 
the body is deep black, and the legs reddish-yellow. 
The wings are somewhat longer than the body, and 
pubescent, each of the upper pair having a triangular 
black spot near the middle of the anterior margin (the 
stigma), three discoidal cells, and a triangular areolet, 
rather imperfectly formed. The abdomen is furnished 
with an ovipositor, consisting of two flat valves, and 
a curved horny sheath, terminating in a point. The 
* Introd. to Entomology, i. p. 76. 
