MINERS 43 



be called neighbourly in their behaviour. If one 

 comes home with an extra fine fly, two or three of 

 her neighbours are likely to try to hustle her 

 with the object of getting possession of her treasure. 

 They all leave off digging and start off hunting at 

 the same time, but they evidently do not all occupy 

 their absence in the same way, for about half the 

 colony come back empty-handed and try to rob 

 those that are laden. They even fight without 

 any apparent casus helium. 



To feed its grub with a succession of flies until 

 it has reached the stage when it spins a cocoon and 

 pupates, is a serious responsibility for the mother 

 Eembex. When Fabre took a partly grown larva 

 from its cell there was evidence in the remains 

 that it had already consumed twenty flies, and he 

 gave it an additional sixty-two as requisite before 

 it ceased feeding. It consumed an average of 

 slightly over ten flies a day. The Peckhams got 

 similar results from their feeding experiments. 



The Bembex grub having finished its feeding 

 prepares for its long period of inactivity prior to its 

 issue as a perfect wasp by constructing a strong 

 cocoon. Its silk-glands do not appear to afford 

 sufficient material for the purpose, but what it 

 has it uses to the best advantage as a cement with 

 which it agglutinates grains of sand, and so elaborates 

 a solid structure well fitted to protect its tender 

 body among the shifting sands, and to keep it dry. 



A North American mining wasp, known as 

 Sfhecius sfieciosus, has been described by Riley as 



