36 PREY OF PARASITES. 



While the infant bee, deep in its perforated cell, is exposed 

 to dangers such as these, the embryo gall-fly sleeps not a whit 

 more safely within its pulpy or woody globe, pierced, often, 

 to the centre, by the egg-inserting instrument of a gall ichneu- 

 mon. Even the little aphis, or plant-louse, cannot escape, 

 through its minuteness, from the punctures of an ichneumon 

 parasite proportioned to itself; and the aphides' arch-enemy, 

 the lady-bird, while yet an aphis-eating larva, is preyed upon 

 in turn by a parasitic consumer. 



The student of insect economy will meet continually with 

 resembling instances of parasitic usurpation, at which, till ac- 

 quainted with its true character, he may often be disposed to 

 wonder almost as much as the early naturalists. Some of 

 these, not a little puzzled by such strange procedures as that 

 of an ichneumon from the egg of a butterfly, or from the nut 

 or apple of a gall-fly, attributed the mystery, for which they 

 wanted a key, to the occasional insufficiency of Dame Nature's 

 producing power, causing her, at times, when she had planned 

 a magnificent butterfly, to turn out only a vulgar fly. 



All the parasites above noticed, if not ichneumons, are, be 

 it remembered, flies parasitic flies, either four- winged, of the 

 order Hymenoptera, or two-winged, of the order Diptera. They 

 are all, also, when arrived as perfect insects at their winged 

 estate, livers upon vegetable food, for themselves, usually, 

 mere harmless sippers of honey. Only in the parental charac- 

 ter are their cruel and parasitic propensities developed, to be 



