185 



Ent, U. S. Dept. Agr., p. 91. 1903) have concluded that all the eggs 

 do not hatch with the first rain after their deposition, but that hatch- 

 ing is completed with the alternation of wet and dry weather. 



Mycetophilid;e 



Bugnoriste occidentalis Coq. 



A single specimen of this small fly was taken on the flowers of 

 Solidago (Sta. I) Aug. 12 (No. 26). The specimen was determined 

 by J. R. Malloch. It had been previously recorded from goldenrod 

 flowers by Aldrich ('05, p. 148). 



Sciara sp. 



These small flies were taken from the flowers of the mountain 

 mint, Pycnanthcnnim flexuosum (Sta. l,g) } Aug. 8 (No. 6). 



BOMBYLIIDiE 



.Exoprosopa fasciata Macq. Giant Bee-flv. 



This was one of the most abundant and characteristic insects of 

 the prairies and cleared areas, and belongs in the same class as the 

 red milkweed beetle (Tetraopcs) and the milkweed bug, Lygccus kal- 

 mii. It was taken from flower masses of the mountain mint Pycnan- 

 themum flexuosum (Sta I, g) Aug. 8 (No. 6); on the flowers of 

 J 7 crbcna stricta Vent, (near Sta. I, a) Aug. 11 (No. 23) ; again from 

 P. flexuosum (Sta. I) Aug. 11 (No. 24.); and on the flowers of 

 Liatris scariosa (Sta. 11, a) Aug. 27 (No. 176). Two specimens 

 had been captured by the flower spider Misumena aleatoria Hentz : 

 one on flowers of the rosin-weed, Silphium integri folium (Sta. II), 

 Aug. 13 (No. 47), the other on flowers of the mountain mint Pycnan- 

 themum flexuosum (Sta. I) Aug. 12 (No. 31) ; and a third was cap- 

 tured by the ambush bug, Phymata fasciata Gray, on the flowers of 

 the mountain mint (Station II) Aug. 13 (No. 57). 



This was a very common species on the prairie patches at Bloom- 

 ington. 111., July 26 to Aug. 23, and in pastures abounding in Verbena 

 at Kappa, 111., and Havana, 111., in August. Graenicher ('10, pp. 94- 

 95) has listed several species of flowers from which this fly has been 

 taken. It is probable that it preys upon some wasps, since a related 

 species, B. fascipenuis Say, has been bred from the cocoons of the 

 white-grub wasp, Tiphia (Forbes, '08, p. 160). 



Systaxhus vulgaris Loew. 



In the cleared area bordering the Bates woods, on flowers of the 

 mountain mint PycnantJiemum pilosum (near Sta. IV, a), a specimen 



