SOME INSECT EXPERIMENTS 137 



been paralyzed, but not killed, by the wasp's terrific sting. Now she 

 lays an egg upon the breast of each of the unfortunate cicadas. When 

 this has been done the burrow is sealed with earth and the young 

 wasps feed upon the paralyzed insects until they reach what is known 

 as the pupal state. In this form they spend the winter, issuing as 

 perfect insects in the following spring. (See chapter XI.) 



It is true that the cicada is larger and heavier, even than the power- 

 ful Sphecid, and it will readily occur to the reader, that to carry 

 such an ungainly burden through the air, would be an extremely 

 difficult undertaking. But here Nature has assisted the insect in ac- 

 complishing her function by supplying a pair of powerful upturned 

 hooks or tongs, one of which is situated upon the under side of each 

 of the wasp's back legs. These she squeezes against the cicada's sides 

 and thus secures her burden during the overland journey to the 

 burrow. 



During the latter part of August, the writer captured one of these* 

 insects, together with a cicada, which it had recently paralyzed. The 

 carrying hooks were then carefully removed from the Sphecid's legs 

 and after several hours, the insect was replaced beside the same cicada 

 which it had been carrying when captured. This was within a few 

 feet of the burrow. Now a remarkable thing happened. The wasp 

 paid not the slightest attention to the cicada, but flew rapidly away 

 among the trees. This I had expected, but to my surprise she re- 

 turned to the burrow within an hour, carrying another victim, appar- 

 ently in her first and second pairs of legs. The cicada was suspended, 

 tail down, in a line perpendicular to the wasp's body; the two insects 

 forming the letter T while in the air. 



This is a most remarkable case, as the Sphecid left the instinctive 

 rut so minutely traveled by her ancestors and instantly adapted her- 

 self to the most extrinsic circumstances imaginable. 



Equally interesting are the results of two experiments upon differ- 



