SAND-WASPS. 



223 



Who would not expect that the mother, judging of her offspring's 

 appetite by her own, would set before them her favourite 

 dainties of roses or apple-blossoms ? But she is taught that 

 her little ones have a far different taste ; and thus, after having 

 dug a hole with her forefeet, scratching the earth like a terrier 

 in pursuit of a mouse, she fetches a spider or a caterpillar, and, 

 not seldom after a hard scuffle, drags her victim to the grave 

 she has provided for its interment. She bites it in the neck, so 

 as to paralyse its resistance, but takes good care not to kill it ; 

 and having laid a single egg upon its body, covers it up and 

 flies away. 



The maggot on creeping forth immediately bites a hole in the 

 body of the spider, which her mother a disinterested assassin ! 

 had wounded for her sake, and begins to suck the juices of 

 the victim with the same eagerness as a leech feasting on 

 human blood. In a few days the exhausted spider expires, and 

 then the maggot devours the flesh and skin, leaving nothing but 

 the hardest parts untouched. 



The ichneumon-fly does not give itself the trouble to 

 overpower the victims destined for the food of its larvae, and 

 to drag them away to a subterraneous den, 

 but follows the easier plan of depositing 

 its eggs in the bodies of other living insects, 

 particularly those of caterpillars. For this 

 purpose many species are provided with a 

 strong and sharp abdominal tube or ovi- 

 positor, which is used to insert their eggs 

 in the bodies of caterpillars that live beneath 

 the bark or crevices of wood. This is gene- 

 rally long, and capable of piercing almost 

 any substance ; while such as have a short 

 ovipositor place their eggs in or upon those 

 caterpillars to which they have easy access. 



Some which select the eggs of butter- ichneumon-fly. <pimpia 

 flies for the residence of their ova are so 

 small that they are scarcely perceptible with the naked eye, 

 while others again from their size and strength are formida- 

 ble even to the large spiders, destroying them with their 

 powerful stings. Someplace their eggs within the aurelia of 

 a nascent insectothers deposit them within the nest which 



