462 



MY GARDEN. 



known, and we often discover one even in the centre of London, by the 

 tone of the buzz, which is much deeper than that of the common wasp. 

 The nest I have figured (fig. 1021) is taken from my work entitled 

 " Instinct and Reason," and the original nest belongs to the British 

 Museum. Entomologists call the Hornet Vespa crabro. 



After bees, which are so directly beneficial to vegetation, and after 

 wasps, which are more or less injurious, we have among the Hymeno- 

 ptera the whole tribe of Ichneumons. These flies, are indirectly of 

 great utility to the gardener, by destroying noxious insects. Some of 



:T 



FIG. 1022. Aphis rapae 

 (magnified 10 diam.). 



FIG. 1021. Wasp's Nest (British Museum). 



FIG. 1023. Colax dispar 

 (magnified 10 uiam ). 



them are large (fig. 1064, No. 5), and deposit their eggs in the 

 largest caterpillars, while others are so minute that they can deposit 

 their ova in the smallest aphides, as the Aphis rapcz (fig. 1022). 

 In both cases the egg hatches, and the creature in which the 

 egg is deposited is gradually eaten up, and instead of changing 

 into a winged creature forms a case from which issues a perfect 

 ichneumon fly. 



Again, there arc some species which deposit their egg in the larvae 

 of the ichneumons, which are preying upon a third creature ; a truly 



