195 



I have also taken this species at Bloomington, III., Aug. 21 and 

 Sept. 7 and 11. 



This wasp has been known in North Carolina to build its nests 

 in the funnel-like bases of the leaves of the pitcher-plant Sarracenia 

 flava (Jones, Ent. News, Vol. 15, p. 17 and PI. III. 1904), and 

 provisions its. nest with CBcanthus. Ashmead (Insect Life, Vol. 7, p. 

 241. 1894) states that it "preys upon the cricket CBcanthus fasciatus 

 Fitch." 



Chlorion atratum Lepeletier (Priononyx atrata St. Farg. and Sphex 

 hnmneipes Cress. ) . Black Digger-wasp. 



This species was taken from the flowers of Bryngium yuccifolium 

 (Sta. II) Aug. 13 (No. 55). I have also taken it at Havana, III, 

 during August, and at Bloomington, 111., on September 3, 5, and 12. 



In a colony of prairie vegetation near St. Joseph, 111., when out 

 with a class on an ecological excursion, Sept. 26, 191 1, I made some 

 interesting observations on this wasp. Along the Big Four railway 

 track between Mayview and St. Joseph, 111., fresh sand and gravel 

 had very recently been placed upon the road-bed. In this fresh sand 

 we observed a large black wasp, Chlorion atratum, digging. The wasp 

 was about two thirds of her length in the hole when first observed, 

 and when captured later she was more than her length in the hole. 

 She would scratch out the sand so that it fell near the mouth of the 

 hole, and then come out and, standing over the pile, she would scrape 

 it far out of the way by rapid movements of her legs. Every now and 

 then she would come out of the hole with gravel in her jaws ; several 

 of such samples were preserved. As the sand was loose the gravel 

 was of course not firmly imbedded. Of the small stones carried out 

 five of the largest range from one fourth to one half an inch in diam- 

 eter. In bulk each of these is larger than the thorax of the wasp. 

 Four small flies were seen to hover about the hole ; some which alighted 

 on small stones near by were captured by a member of the party and 

 proved to be small tachinids (No. 309, C.C.A.), which Mr. J. R. 

 Malloch determined to be Metopia leucocephala Rossi. ( Cf . Coquillett, 

 '97, p. 127.) Mr. Malloch also called my attention to recorded obser- 

 vations on other tachinid flies which inhabit the burrows of Hymenop- 

 tera in Great Britain, and are parasitic in habit (Malloch, 09). Hamm 

 ('09b) has described how one of these flies, Setulia grisea Mg., follows 

 the females of Cerceris as she provisions her burrow with weevils. 

 They were observed to enter and to come out of the burrow. Me- 

 lander and Brues ('03, pp. 9, 20) state that M. leucocephala infests 

 the bee Halictus by choosing "the moment when the incoming bee 

 pauses at her threshold quickly and quietly to oviposit on her pollen 

 mass and thus infect her offspring." This fly has been reported to be 



