DISEASES OF INSECTS. 233 
talis intricarius ,• and when that fly was placed amongst 
them, they immediately attached themselves to it, so as 
to leave no doubt of their identity a . A congenerous 
species had been detected upon wild bees, and described 
by Linne under the name of Pediculus Apis. De Geer 
is so thoroughly to be depended upon for his veracity 
and accuracy of observation, that we cannot suppose 
there is any incorrectness in his statement. If the mass 
of eggs be, as he represents it, of the size of a hazel-nut, 
it must have been the product of a very large insect: 
in confirmation of this opinion it may be further ob- 
served, that the larva of the kindred genus Cantharis 
agrees with it in having anal setas, though it appears to 
differ in having only two conspicuous segments in the 
trunk b . Those which infest wild bees make their first 
appearance upon acrid plants, which the Meloe likewise 
feeds upon ; from whence with wonderful agility they 
leap upon the Andrence, &c. that visit these flowers. 
Strong, however, as all these facts appear, still we cannot 
help exclaiming with the illustrious Swede last named, 
Who could ever have imagined that the larva of this 
great beetle would be found upon the body ofjlies, — and 
we may add, or bees P Who could ever imagine that it 
would feed like a bird-louse and resemble it so closely ? 
that in the insertion of its palpi it should exhibit a cha- 
racter exclusively belonging to that tribe ? Another 
circumstance seems to indicate that these hexapods at the 
time that they take their station in bees or flies are per- 
fect insects — they do not vary in size, at least not mate- 
rially. Where, we may also ask, if they are to become 
a Dc Geer v. 8 — . 
h Naturf. xxiii. /. \.f. 8. c N. Diet, d' Hint. Nat. xx. 110—. 
