102 



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WILD LIFE IN CALIFORNIA 



tion. We could not see how she was doing 

 the work, for she was operating from the in- 

 side and only a small part of her posterior 

 was visible. 



We left the wasp at her work, but return- 

 ing in about an hour we found the hole com- 

 pletely filled even with the face of the bank, 

 and therefore were disappointed in not hav- 

 ing been able to witness this final operation. 



Marking the spot for future observation 

 we left it undisturbed for a week. At the 

 end of this period we concluded to excavate 

 the nest and ascertain if possible what had 

 taken place within the depths. By carefully 

 cutting down the bank we found the hole en- 

 tered the earth on an incline of about 25 de- 

 grees to a depth of nearly five inches. We 

 found the remains of the spider in a rather 

 advanced stage of decomposition, indicating 

 that the wasp had killed it at the time of cap- 

 ture instead of paralyzing it. To our surprise 

 we found no larva. 



Evidently the wasp had not deposited an 

 egg in the nest with the spider. However, 

 failures of this nature have been noted by 

 several students of the habits and actions of 

 the members of the wasp family. So the seem- 

 ing neglect of our wasp was not an exceptional 

 case, strange as it may appear that after all 

 the labor and trouble she had experienced in 

 preparing the nest, capturing the spider and 

 hoisting it to the cell she should then fail to 

 perform the one act for which all her work 

 and time expended was the sole purpose. 



Another interesting incident witnessed while 

 watching the operations of the wasp was the 

 action of a small fly of the same species men- 

 tioned in the stories of the Digging Wasps. 

 From its actions it evidently was watching for 

 an opportunity to deposit some of its eggs on 

 the body of the spider. When the wasp was 

 struggling to place the spider in the hole the 

 fly remained perched on a rootlet near the 

 entrance turning this way and that way so 

 that it could see all that was taking place. 

 When the wasp would disappear in the hole 

 the fly would instantly hover over the mouth 



of it, but retreat as quickly when the wasp 

 came out. The behavior of the bold little in- 

 sect clearly indicated that it fully understood 

 the object and purpose of the wasp as well 

 as recognized her dangerous character. The 

 wasp was so long engaged in the operation of 

 burying the spider that the fly probably be- 

 came impatient, for it went away before the 

 wasp succeeded in its efforts. 



It is well known among entomologists that 

 the method attempted by the fly is one, if 

 not the only one, adopted by its species for the 

 perpetuation of its kind. The eggs of the fly 

 hatch quickly and the larvae appropriate the 

 provisions provided by the wasp. If the egg of 

 the latter hatches the larva also becomes a 

 victim in satisfying the voracious appetites of 

 the growing fly babies. 



This wasp belongs to the division known as 

 Psamimocharidae, all members of which prey 

 chiefly on spiders. There are several species 

 of which the Tarantula hawk, or Pepsis, is 

 one. This is a giant among the wasps and 

 preys upon Tarantulas, the giants of the spider 

 race. 



Since writing the foregoing I have had the 

 pleasure of reading Phil and Nellie Rau's 

 "Wasp Studies Afield" and found a story of 

 their observation of the actions of a spider 

 hunting wasp in disposing of a spider in a 

 hole in a bank, in Missouri, wherein the con- 

 ditions and circumstances were quite similar 

 to those related by me. In their case, however, 

 the wasp made twenty or more attempts before 

 it succeeded in getting its victim in the hole. 

 The method^ and actions of their wasp were 

 so nearly the same as the Brookdale wasp one 

 might be justified in assuming they were of 

 the same specie. 



Priocnemls pompilus is the name given to 

 the wasp described by the Raus. Not having 

 collected any specimens of the Brookdale wasp 

 I am unable to give the species to which it 

 belongs or be more definite than to say the 

 one observed by me is a member of the 

 Psammocharidae family, as is the ine noted 

 by the Raus. 



