O 



BULLETIN 



OF TIIK 



ILLINOIS STATE LABORATORY 

 Natural History. 



VOLUME III. 



Article I. — ii^otes on Some Illinois Microg aster s : ivith De- 

 scriptions of New Species. By Clarence M. Weed, M. Sc. 



[In working over the material by whicli the interesting 

 group of Microgasters is represented in the collections of the 

 Laboratory, so much of interest was found that it was thought 

 worth while to record at this time some of the more important 

 facts. The writer desires to express his thanks to Prof. S. A. 

 Forbes for permission to study the collections and use the 

 notes, as well as for many other favors; to Dr. C. V. Riley, who 

 has very kindly verified the determinations; and to Dr. A. S. 

 Packard, Prof. H. Garman, and Mr. Chas. W. Woodworth for 

 favors received.] 



MicROPLiTis CERATOMiiE, Riley. 



This species was bred by Dr. Riley from Ceratomia quad- 

 ricornis, in Missouri.* During the summer of 1885, from a 

 larva of the sphinx just mentioned, confined in a breeding cage 

 at Champaign, there emerged eighty-four of the Microplitis 

 grubs, which spun parallel, leathery, ribbed cocoons upon the 

 back of their host.- The cocoons were formed in two longitud- 

 inal series, one on each side of the dorso-median line of the 

 larva, which were connected with a posterior transverse series. 

 On the 25th of May, 1886, the adults began to emerge, and con- 

 tinued to issue until June 5. They agree with Riley's descrip- 

 tion (1. c), except that they are larger, the majority of them 

 being 3 mm. long, and some even reajhing 3.5 mm. The 



*Notes on North American Microgasters, Trans. St. Louis Acad. 

 Sci., Vol. IV., p. 303 [8]. 



