A Parasite of the Bembex 291 



awed by the fearsome appearance of her Toad- 

 faced nurseUng, accepts and looks after the 

 stranger : this theory has some plausibihty. 

 But what should we say if the Warbler turned 

 parasite and, with superb audacity, went and 

 confided her eggs to the eyrie of the bird of 

 prey, to the nest of the Sparrow-hawk himself, 

 the bloodthirsty devourer of Warblers ? What 

 should we say if the rapacious Hawk accepted 

 the trust and fondly reared the brood of little 

 birds ? And this is exactly what the Bembex 

 does, that ravisher of Flies who tenderly 

 nurses other Flies, that huntress who provides 

 food for a quarry whose last meal will be made 

 on her own disembowelled larva ! I leave it 

 to others, cleverer than myself, to interpret 

 these astonishing relations. 



Let us observe the tactics employed by the 

 Tachina for the purpose of confiding her eggs 

 to the Digger's nest. It is an absolute rule that 

 the Gnat never enters the burrow, even though 

 she should find it open and the owner absent. 

 The sly parasite would think twice about 

 venturing down a passage where, being no 

 longer free to escape, she might pay dear for 

 her brazen effrontery. For her the one and 

 only favourable moment for her designs, a 

 moment awaited with exquisite patience, is 

 that at which the Wasp dives into the gallery, 



