42 Some Solitary Wasps of Texas. 



The nest of melleus is always left open, day and night, which 

 might give inquilines and parasitic flies a chance to get in. But 

 the narrcwTiess of the nest (two or three mm. in diameter) would 

 keep out large flies and the great depth (12 inches) would tend to 

 prevent smaller flies from finding the store of food. 



The excavation is carried out after the usual manner of wasps, 

 the sand being loosened with the mandibles, scratched back with the 

 forefeet and kicked out with the hind pair. The work of digging 

 the nest is all done at once, though some dirt is brought up from 

 time to time after the provisioning has been begun. 



My first specimen. No. 15, alighted in the bottom of the pit 

 shown in Fig. 24 and walked over to her nest. It is the habit of 

 the species to alight from three inches to a foot from the nest and 

 then run over to it. No. 15 carried in her mandibles a small green 

 leaf -hopper {Tettigonia bifida. Say). She entered the nest, re- 

 mained inside a few seconds and was off again. She returned in 

 three minutes with another leaf-hopper and made two more trips 

 in seven minutes each by 5 :19 p. m., when I left her. On my ar- 

 rival at 10 :00 the next morning she had been doing a little dig- 

 ging. At 10 :30 she came up to the entrance waving her long an- 

 tennae at me and looked out. She then protruded her whole head, 

 examined the weather and slowly crawled forth. Soon another 

 individual was running around, evidently getting ready for the 

 day's hunt. This one was, however, destined to be shortlived, for 

 she ventured too near a spider's nest, whose owner, a perfect mimic 

 of the sand, was lying in ambush. Quick as a flash the spider was 

 upon the wasp, gave it a bite and as quickly returned to its lair. 

 The wasp collapsed in the same instant. 



At 11 :15 the first individual which I had been watching and 

 which had returned into the nest, now came forth and, after mak- 

 ing a locality study, was off. 



As a storm was approaching, I captured the wasp on her next 

 return, eighteen minutes later and dug up the nest. I found it to 

 extend downward in a gentle slope for a distance of twelve inches 

 to a chamber of one-half inch in diameter. The chamber contained 

 seven leaf-hoppers but no egg. 



Alyson oppositus is also common. It is somewhat smaller than 

 A. melleus and shows its consanguinity to this species by the small 

 round dot on each side of its abdomen as well as by its actions while 

 on the hunt. 



