584 



AMERICAN SPIDEBS AND THEIR SPINNINGWORK. 



I obtained no other species from these nests, but cannot atRrm that no 

 other escaped.' It may be a question, perhaps, whether the mud daubs 

 were made by Chalj'bion or Trypoxylon ; Vnit we have the great authority 

 of the late Benjamin D. Walsh that the latter species is really a guest wasp, 

 not building and provisioning any nest for itself, but laying its eggs 

 in the nest built and provisioned by the former, thus appropriating 

 for its own future pi'ogeny the spider store laid up by the industrious 

 Chalybion for its young. '^ It is curious and suggestive to trace this use 

 and wont from the guest wasp and the cuckoo up to the human species 

 as represented alike by the imperial " annexers " of Europe, Africa, and 

 the Orient, and the " land grabbers " of the Indian Territory, the " scjuat- 



ter sovereigns " of the border, and the 

 " claim jumpers " of Rocky IMountain 

 mining districts. 



Among the wasps that provision 

 their nests with single spiders is the 

 common blue digger wasp, Chlorion 

 cteruleum Drury (Sphex), which, un- 

 like species hitherto alluded to, bur- 

 rows in the earth. It excavates its 

 egg nest in an incredibly short time, 

 sometimes consuming not more than 

 a minute or a half minute, and then 

 places therein a single egg together 

 with a spider, which is generally a 

 large one. With its front jtair of feet 

 it then .scrajies back the dhi which 

 it liad witlidrawn, frequently stopping 

 to pat it down with its abdomen. 

 When the hole is filled the surface 

 is smoothed to the level of the sur- 

 rounding soil. The large and beauti- 

 ful Elis 4-notata Fabr. (Scolia), (l*late 

 v.. Fig. 3j, invades the burrows of 

 Lycosids, especially Lj^cosa tigrina, 

 and the small Priocnemus pomilius Cres.son has been taken while carrying 

 a Laterigrade, a species of Xysticus, in its jaws. 



Another example of wasps that store single spiders is the large and 

 beautiful Pepsis formo.sa Say (Pompilus), an inhabitant of the 

 Sovithwestern States of North America, where it is poi^ularlj- 

 known as the "tarantula killer." (Plate V., Fig. 2.) This 

 name is given because of its habit of storing its burrow with that most 



Fig. 326. Series of "Pipes of Pan" mud daub cells, 

 from which escaped Trypoxylon politum. 



Tarantula 

 Killer. 



' Tlu' figure here given (Fig. 326) was drawn from a series sawed out of a shed at Bell- 

 wood, Pennsylvania. ^American Entomologist, Vol. I., page 133. • 



