194 



A specimen was taken Aug. 21 at Bloomington, 111. The yellow 

 wings and antennae, and yellow subapical wing spot on the smoky 

 wings make this a conspicuous species. The family name Pompilidcc 

 was formerly used for these wasps. 



Sphecid^: 

 Ammophila nigricans Dahlb. 



A single specimen was taken from the flowers of Pycnanthemum 

 flexuosum (Sta. I) Aug. 11 (No. 24). 



This is a very common Illinois species. I have taken it at Bloom- 

 ington from June 22 to September 9, at Havana during August, and 

 at Chicago, August 19 and 28. A specimen taken August 2 at Bloom- 

 ington, 111., was digging in the ground when captured. 



Chlorion ichneumoneum Linn. (Sphex ichneumonea Fabr. ). Rusty 

 Digger-wasp. (PI. L, fig. 1.) 



This insect, abundant on flowers of the swamp milkweed, Ascle- 

 pias incarnata, August 8, was taken on them at Sta. I, g, Aug. 8 (No. 

 1) and at Sta. I,d, Aug. 9 (No. 12); and on the mountain mint 

 Pycnanthemum flexuosum (Sta. I) Aug. 8 (No. 6). It was also 

 taken by T. L. Hankinson July 3, 191 1 (No. 7665). 



This is a very common insect on flowers in central Illinois. I have 

 found it abundant at Chicago during August; at Bloomington, 111., 

 from June 24 to Oct. 1 ; at Mayview on Sept. 26 in a colony of prairie 

 vegetation. 



Packard (Guide to the Study of Insects, pp. 167-168. 1870) tells 

 how these wasps dig holes four to six inches deep in gravel walks, and 

 after capturing long-horned grasshoppers, Orchelimum vulgare or 

 O. gracile, and stinging and paralyzing them, proceed to bury them. 

 The egg is deposited on the locust before the soil is scraped in. (Cf. 

 Walsh, Am. Ent, Vol. 1, p. 126. 1869). For an excellent account of 

 the habits of this species consult the Peckhams, "Instincts and Habits 

 of the Solitary Wasps" (1898). See Fernald ('06) for the recent 

 synonymy. 



Chlorion pennsylvanicum Linn. Pennsylvania Digger-wasp. 



This wasp was taken on the flowers of Bryngium yuccifoliuni 

 (Sta. II) Aug. 13 (No. 55). On Aug. 8, 1893, I captured a specimen 

 at Chicago. (Cf. Fernald, '06, p. 405.) 



Chlorion harrisi- H. T. Fernald {Isodontia philadelphica Auct.) . Har- 

 ris's Digger-wasp. 

 One specimen of this wasp was taken on flowers of the mountain 

 mint Pycnanthemum flexuosum (Sta. I) Aug. 11 (No. 24). 



