232 DISEASES OF INSECTS. 
mals quit their prey sooner. Reaumur saw a grub of 
one of the Muscidce come out of a caterpillar, and then 
become a pupa, which was so large that he wondered 
how it could have been contained in the animal it had 
quitted a . 
We have now done with those parasites that produce 
in insects the disease I have called Scolechiasis h : the 
rest, which belong to the Aptera Order, will afford us 
examples both of Phthiriasis and Acariasis c . 
I begin with theirs/. Mr. Sheppard once brought 
me a specimen of a bird-louse (Nirmus) which he took 
upon a butterfly ( Vanessa Io) : and should such a capture 
be more than once repeated, it would afford a certain 
instance ofthejirst of these diseases amongst insects; — but 
most probably the specimen in question had dropped 
from some bird upon the butterfly. The only remaining 
animal belonging to the apterous hexapods that is para- 
sitic on insects, is by many supposed to be the larva of a 
giant-beetle (Meloe Proscarabams). I have before alluded 
to this animal d , and shall now resume the subject. Gee- 
dart, Frisch, and De Geer, observed that it deposited in 
the earth one or two considerable masses, containing an 
infinite number of very minute orange-coloured eggs 
adhering to each other, which in about a month were 
hatched, and produced a number of small hexapods dis- 
tinguished by two pairs of anal setae and a proleg, by 
means of which they could move readily upon glass, as I 
have myself seen : these little animals precisely corre- 
sponded with one found by the latter author upon Eris- 
a Keauiii. ii. 440 — . 
" Vol. I. p. 99. r Ibid. 84, 97. 
" Vol. I. p. 163. note c . Vol. HI. p. 162. note ". 
