318 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



and spinous legs burrow with great rapidity in the ground, where they 

 form a sort of nest } provision it with some kind of prey which they 

 have stung and paralyzed ; lay an egg thereunder, and cover up the 

 hole— the larva when it hatches feeding upon the stored foodthus pro- 

 vided by the parent. Several species have long been known to capture 

 locusts and green grasshoppers. We noticed a small black species 



{Priononyx atrata, St. Farg.) 

 that is quite common in Co- 

 lorado, pursuing and capturing 

 the pupa of C. spretus, and Mr. 

 Packard caught a still smaller 

 species {Larrada semirufa, 

 Cress., Figs. 55, 56), with black 

 head and thorax and reddish 

 abdomen, whileit was in the act 

 of carrying a spretus larva. One 

 of our handsomest species 

 {Sphex ichneumonea L., Fig. 57), 

 with golden pubescence on head 

 ^ ^^ c. ,.^. ^ . and thorax and with the legs 



Fig. 57.— Sphex ichneumonea. (After Emerton.) ^ 



and basal half of abdomen rust- 

 red, has been closely observed by Mr. Packard, and we copy the fol- 

 lowing account of its habits from his Guide to the Study of Insects 



(p. 167): • . 



In the last week of July, and during August and early in September, we noticed nearly 

 a dozen of these wasps busily engaged in digging their holes in a gravelly walk. In 

 previous seasons they were more numerous, burrowing into grassy banks near the 

 walk. The holes were four to six inches deep. In beginning the hole, the wasp 

 dragged away with its teeth a stone one-half as large as itself to a distance of eight 

 incbes from the hole, while it pushed away others with its head. In beginning its 

 burrow it used its large and powerful jaws almost entirely, digging into the depth of 

 an inch in five minutes, completing its hole in about half an hour. After having in- 

 serted its head into the hole, where it loosened the earth with its jaws and threw it 

 out of the hole with its jaws and fore legs, it would retreat backward and push the 

 dirt still farther back from the mouth of the cell with its hind legs.' In cases where 

 the farther progress of the work was stopped by a stone too large for the wasp to re- 

 move or dig around, it would abandon it and begin a new hole. Just as soon as it 

 reached the required depth, the wasp flew a few feet to an adjoining bank, and falling 

 upon an Orchelimum vulgare or 0. gracile (two common grass-green catydid-like grass- 

 hoppers, about an inch long), stung and paralyzed it instantly, bore it to its nest, and 

 was out of sight in a moment, and while in the bottom of its hole must have deposited 

 its egg in its victim. Reappearing, it began to draw the sand back into the hole^ 

 scratching it in quite briskly by means of its spiny fore tarsi, while standing on its 

 two hind pa'rs of legs. It thus threw in half an inch of dirt upon the grasshopper 

 and then flew off. In this way one Sphex will make two or three such holes in one 

 afternoon. The walk was hard and composed of a coarse sea-gravel, and the rapidity 

 with, which the wasp worked her way in with tooth and nail was marvelous. 



A steel-blue species {Chlorion coeruleum Drury, Fig. 58), though ordi- 

 narily using spiders, also employs locusts 5 and the following extract from 



