BEHAVIOR OF POMPILID WASPS 79 



flew further, but she was recognized immediately by the 

 bright red of her abdomen and, in the bright sunlight, her 

 bluish-tinted wings. Her brilliant coloration and her nerv- 

 ous, defiant manner certainly render her a formidable look- 

 ing creature (fig. 15). In cabinet specimens of this species, 

 the red of their bodies looks far more dull, and the wings, 



FIG. 15. The Pompilid wasp, Arachnophoctonus ferrugineus Say. 

 Exact size. 



which are a conspicuous royal blue when vibrating in the 

 sunshine, are but a smoky color with a slight blackish-blue 

 tinge at the base. 



After having frightened her away, we proceeded to ex- 

 amine the loose mortar for her nest or prey. We were 

 attracted to a pile of loose, dry plaster-dust on the damp 

 earth; this pointed up to the third tier of rock, probably 

 eighteen inches from the ground, where a large Lycosa 

 spider lay in the crevice, about an inch from the opening. 

 It was removed and found to be fresh, limp and motionless ; 

 it was probably dead, so we replaced it and waited. After 

 fifteen minutes the wasp flew into the vicinity again, but 

 became shy upon seeing us there. After another ten min- 

 utes she ventured near again and alighted on the stone wall 

 at a height of six feet, and east of the nest; then walked 

 down and westward, entering and examining several holes 

 and remaining in some of them for a few seconds. She 

 eventually found the crevice containing the spider, en- 

 tered and examined it $Q intently that we, wondered if she 



