WASPS, SOCIAL AND SOLITARY 



P. marginatus is not troubled by any notion as to 

 the family connections of the spider that she takes. 

 Anything will do provided she is strong enough to over- 

 come it and carry it to her nest. The effect of her sting 

 is quite variable, since in some cases the victim was 

 killed at once, while in others it was but little affected 

 in the beginning and lived for eighteen or twenty days. 



At eleven o'clock on the morning of a warm day in 

 mid-August we saw the steel-blue Pompilus scelestus 

 dragging a big Lycosid across a field. The spider was 

 sixteen millimeters long and wide in proportion, while 

 the wasp was but thirteen millimeters long and very 

 slender, so that the weight of the spider was at least 

 three times that of its captor. The necessity for going 

 backward was evident in this case, but the wasp moved 

 rapidly considering the load that she was dragging. 

 As she worked her way along she made frequent pauses, 

 stopping for two or three minutes at a time in some little 

 hollow, or under leaves or weeds. She spent a good 

 deal of time, during these pauses, in cleaning herself, 

 and a good deal of time also in doing something to the 

 spider which we could not understand. She seemed to 

 be biting the legs, near the body, beginning with an an- 

 terior leg on one side and working backward, and then 

 repeating the operation on the other side. She went 

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