ENEMIES AND THEIR INFLUENCE. 383 



shriveled, the egg probably having proved infertile. Again, a few spiders 

 would be dried up, while others were plump and edible, a condition in 

 which more frequently most of them are found. It is certainly one of 

 the unhappy possibilities in the destiny of the spider that it may be con- 

 strained to abide in a living death within this dark vault awaiting the 

 awakening appetite of a voracious worm. It is to be hoped that a kindly 

 Nature has so far tempered this hard doom as to deprive the entombed 

 creature of all consciousness of her condition and consequent suffering 

 therein. Indeed the evidence is well nigh conclusive that sensation is 

 wholly suspended at the prick of the insect's sting. 



III. 



With the single exception, perhaps, of one small order, Neuroptera, no 

 order of insects is exempt from the attacks of the all devouring wasps. 

 Some provision their nests with grasshoppers, some with cockroaches, some 

 with snoutbeetles of various kinds, 

 some with ants and bees, a few with 

 different kinds of bugs, frog spittle, 

 insects, and plant lice; a great num- 

 ber of them with various kinds of 

 two winged flies, and a still greater 

 number, perhaps, with the larvae of 

 various moths. 1 Most observing coun- 

 try lads have noticed the assault of 

 the handsome digger wasp, Sphecius 



_. .-. , . ._. ,-._, FIG. 325. The Cicada wasp (Sphecius speciosus.) 



speciosus Drury (Sphex), (rig. 325), 



upon the so called "locust," the cicada or harvest fly, and I have dug 

 that insect, Cicada pruinosa, out of a burrow of this wasp in the terrace 

 of a West Philadelphia yard. 



Those wasps which prey upon spiders comprise many distinct species 

 belonging to widely separated genera. Some of these gather many spi- 

 ders into one cell, others only one. The insects heretofore noticed are of 

 the former class, the species most destructive in this region being prob- 

 ably the common indigo blue mud dauber, Chalybion caeruleum Linn. 

 (Sphex). (Plate V., Fig. 7, natural size.) The larval cells of the blue 

 mud dauber are commonly laid in small masses, one on top of another. 

 (Fig. 323.) The cells of the common mud dauber are composed of one 

 or more layers or tiers of clay tubes, arranged one above another or side 

 by side like a set of Pan's pipes, and cemented to some surface protected 

 from the weather. One such specimen, collected in the autumn (Fig. 326), 

 I kept in my cabinet, and about the beginning of July following, a num- 

 ber of black digger wasps, Trypoxylon politum Say, escaped therefrom. 



1 Walsh, American Entomologist, Vol. I., No. 7, 1869, page 126. 



