1892.] ENTOMOLOGICAL NEWS. 85 



NOTE ON THE HABITS OF AMMOPHILA. 



By S. W. WILLISTON, Lawrence, Kans. 



Even the casual observer, to whom all insects are bugs, cannot 

 help but be struck by the great diversity and number of the fos- 

 sorial Hymenoptera of the plains. Water is often inaccessible, 

 trees there are few or none, and only in places is the vegetation 

 at all abundant. A much larger proportion of insects, hence, 

 find it necessary to live or breed in holes in the ground, than is 

 the case in more favored localities. Especially is this the case 

 with the Hymenoptera, great numbers and many species of which 

 thus breed in excavations made by themselves. 



While packing specimens on an open space, uncovered by 

 buffalo grass, in the extreme western part of Kansas, the early 

 part of last July, the attention of a friend and myself was attracted 

 by the numerous wasps that were constantly alighting upon the 

 ground. The hard, smooth, baked surface showed no indications 

 of disturbance, and it was not till we had attentively watched the 

 insects did we learn what they were doing. The wasp is a very 

 slender one, more than an inch in length, with a slender, pedicel- 

 late abdomen; it is known to entomologists as Ammophila Yar- 

 rowi Cres. They were so numerous that one was distracted by 

 their very multiplicity, but, by singling out different individuals, 

 we were enabled to verify each detail of their operations. An 

 insect, alighting, ran about on the smooth, hard surface till it had 

 found a suitable spot to begin its excavation, which was made 

 about a quarter of an inch in diameter, nearly vertical, and car- 

 ried to a depth of about four inches, as was shown by opening a 

 number of them. The earth, as removed, was formed into a 

 rounded pellet and carefully carried to the neighboring grass ami 

 dropped. For the first half of an inch or so the hole was made 

 of a slightly greater diameter. When the excavation had been 

 carried to the required depth, the wasp, after a survey of the 

 premises, flying away, soon returned with a large pebble in its 

 mandibles, which it carefully deposited within the opening; then, 

 standing over the entrance upon her four posterior feet, she I 

 say she, for it was evident that they were all females) rapidly and 

 most amusingly scraped the dust with her two trout feet, " hand 

 over hand," back beneath her, till she hail tilled the hole above 

 the stone to the top. The operation so far was remarkable 



