io6 INSECT LIFE 



Vltl 



security, and not the habits of the grub, which 

 determine the mother where to place its egg. 



A suspicion suggests itself to me as to this. 

 The first cricket, the ration on which the egg is laid, 

 exposes the grub to more risks than do the others. 

 First, the larva is still a weakly creature ; next, the 

 victim was only recently stung, and therefore in the 

 likeliest state for displaying some remains of life. 

 This first cricket has to be as thoroughly paralysed 

 as possible, and therefore it is stabbed three times. 

 But the others, whose torpor deepens as time passes, — 

 the others which the larvae only attack when grown 

 strong, — have they to be treated as carefully ? Might 

 not a single stab, or two, suffice to bring on a 

 gradual paralysis while the grub devours its first 

 allowance ? The poison is too precious to be 

 squandered ; it is powder and shot for the Sphex, 

 only to be used economically. At all events, if at 

 one time I have been able to see a victim stabbed 

 thrice, at another I have only seen two wounds 

 given. It is true that the quivering point of the 

 Sphex's abdomen seemed seeking a favourable spot 

 for a third wound ; but if really given, it escaped my 

 observation. I incline to believe that the victim 

 destined to be eaten first always is stabbed three 

 times, but that economy causes the others only to be 

 struck twice. The study of the caterpillar-hunting 

 Ammophila will later confirm this suspicion. 



The last cricket being finished, the larva sets to 

 work to spin a cocoon. In less than forty-eight 

 hours the work is completed, and henceforward the 

 skilful worker may yield within an impenetrable 

 shelter to the overpowering lethargy which is steal- 



