SOME SOCIAL WASPS 281 



have often seen them stand in the midst of a body of water, 

 without any disaster, to drink. While intently watching 

 her alight, we were startled to hear a shrill shriek as a 

 frog from under the bank pounced upon her and disap- 

 peared under the water. The frog had been at rest on the 

 shore twelve inches from the spot where the wasp sought 

 anchorage, and he jumped, captured her, shrieked and 

 dived all in less time than it takes to tell. It all went so 

 quickly that one could not tell whether the frog shrieked 

 before or after it captured the wasp, but anyone who might 

 have heard it would agree with us that there was agony 

 almost human in that scream, and we do not think we are 

 asking too much license in letting our fancy explain the 

 case for us. 



At Meramec Highlands, on August 17, 1915, we saw a 

 P. rubiginosus behaving queerly on the ground. We 

 watched it for a few seconds, when suddenly she pounced 

 upon a green caterpillar on the under side of a leaf above 

 her head, invisible to us but clearly within her view, from 

 her position on the ground. She carried it to the upper 

 side of the leaf and began to malaxate it all along its body, 

 for several seconds, and then continued to bite, chew and 

 eat its anterior portion. After she had eaten about one- 

 fifth of the caterpillar, she again practiced malaxation on 

 the remainder; then, after resting quietly on the leaf for 

 some minutes, she flew away. After she had eaten her fill 

 and had taken the pains to knead the remainder, we were 

 surprised that she did not carry it to the nest. 



On a sunny afternoon at the very end of the wasp season, 

 October 13, a number of P. rubiginosus and P. annnlaris 

 were observed on the south side of the old rock ice-house 

 at Meramec Highlands. It seemed as though they were at 

 play, flying to and fro against the building, resting a while 

 and occasionally chasing one another. Most of them 



