MUD-DAUBING WASPS 119 



teen days after pupation, and the others twenty-two days 

 after spinning. 



The Peckhams gauge the quality of the sting of wasps by 

 the longevity of the victim, but in our opinion the size, vital- 

 ity and species of the spider should be taken into account. 

 The Pelopoeus or Chalybion may give a sting of standard 

 size to all of her prey, regardless of their size. It remains un- 

 known whether the larger spiders live longer than the smaller 

 ones. We found great variation in the longevity of the spi- 

 ders from one new Pelopoeus cell. -The wasp's egg was still 

 new and unhatched, so we knew that the spiders had not 

 been entombed more than one day at most. On the day of 

 discovery, August -ii, they all moved their legs actively, 

 but their vigor gradually waned; on August 19 the first one 

 died, after having lived 8 days after being stung, and the 

 other seven lived respectively 8, 10, 14, 14, 14, 25 and 

 32 days. 



Our actual observations have confirmed Peckhams' sus- 

 picions that the choice, tender abdomens of the spiders are 

 first eaten by the young larva, and later, if there is need for 

 more food, the legs are served for a second course. 



A completely melanic specimen of male Sceliphron cac- 

 mentarium was seen getting nectar from the flowers of 

 smartweed. When taken up in the hand, it pretended to 

 attempt to sting by curling and passing its abdomen over the 

 finger, much in the manner of a more formidable female. 



One July day we were startled to see a Pelopoeus leisurely 

 flitting from flower to flower, with the entire abdomen gone, 

 only the basal segment remaining. She seemed lively enough, 

 and just as happy as though she were all there. We took 

 her home. The next day she appeared the same, but we 

 could not see how she could escape misery, so consigned her 

 to the cyanide bottle. Packard 2 records a female Pelopoeus 



2 Psyche 2: 18. 1877. 



