GB INSIiCT TRANSFORMATIONS. 



It is not comnioii, however, for the ichiieuinon- 

 flies to deposit their eggs, in the bodies of perfect 

 insects, as in most cases they prefer the egg-s, larvie, 

 or pupae ; but instances are on record of their grubs 

 having been found in the former. The troublesome 

 cock-roach {Blattd) is selected by a parasite-fly 

 (Evania apendigaster, Fabu.), as remarkable in 

 form as it is rare in occurrence, in Britain at least. 

 It has been found in the vicinity of London ; but, 

 were it abundant, it might tend to reduce the num- 

 bers of these black beetles, as they are incorrectly 

 termed, the pests of the kitchen. 



Magnified view of a parasite-fly (^Evania apendigaster). 



An insect parasite, still more singular in form, 

 and of still rarer occurrence, was discovered by 

 Kirby, above thirty years ago, on the black bronze 

 bee {Andrena nigro^nea, Stephens). " I had pre- 

 viously,'' he remarks, " more than once observed 

 upon other species something that I took to be a kind 

 of Acarus, which appeared to be immoveably fixed 

 just at the inosculations of the dorsal segments of the 

 abdomen. At length, finding three or four upon a 

 specimen of this bee, I determined not to lose the 

 opportunity of taking one off to examine and de- 

 scribe; but what was my astonishment, when, upon 

 my attempting to disengage it with a pin, I drew 

 forth from the body of the bee a white fleshy larva, 



