io6 



THE FOOD OF ANIMALS 



all the large grubs they drag to light." The same naturalist 

 gives an account of certain blind species of these ants which 

 construct covered roads from grains of earth, under which they 

 march to suitable hunting grounds. For further details on this 

 fascinating subject the original work must be consulted. 



Besides predaceous social ants there are also solitary ones of 

 similar habit, some of these being British (as, e.g., Mutilla Europcect). 



SAND-WASPS. There are many hymenopterous insects which 

 provide a store of suitable food for their carnivorous young, 



Fig. 384. Bird -catching Spider (My gale] threatened by a Sand-Wasp (Pepsis] 



a subject which will be entered into more fully later on when 

 the care of young is under consideration. It will suffice to say 

 here that -Sand- Wasps, solitary insects of various species, lay 

 their eggs in holes in the ground or elsewhere, sometimes digging 

 these out themselves, and drag into these holes caterpillars, 

 adult insects, or spiders, previously stinging them in the nerve- 

 cord so as to paralyse but not kill them. Different species of 

 wasp select different victims for the purpose. The Common 

 Sand- Wasp (Ammophila sabulosa) prefers caterpillars, the Path- 

 Wasp (Pompilus viaticus) spiders, and the Field Sand -Wasp 

 (Mellinus arvensis) flies. 



Fig. 384 represents a huge South American spider (Mygale) 

 threatened by a large wasp (species of Pepsis] of this kind. 



