1919] King: Biology of the Carabid 387 



which the egg cells are found. The larvae of Brachynus cyani- 

 pennis mentioned in this paper, are parasitic on the pupae of 

 Dineutes discolor. 



Parasites. 



A number of minute Hymenopterous parasites have been 

 reared from the egg cells of these Carabids. With Brachynus 

 as high as fifty per cent of the eggs found in nature were 

 parasitized by tiny winged and wingless Hymenoptera of the 

 genus Hoplogryon. All parasites of C. impunctifrons, C. 

 aestivus, and C. tricolor were winged. In one habitat studied 

 the eggs of C. tricolor were parasitized to the extent of twenty- 

 five per cent, by a minute Hymenopteron, Prosacantha caraborum 

 Riley, which is a common parasite of several species of Chlaenius. 



Acknowledgments. 



The author is indebted to Mr. H. B. Kirk, entomologist, 

 Pennsylvania Bureau of Plant Industry, who so kindly con- 

 tributed his time and patience in taking the photographs herein 

 used. He also acknowledges the kindness of Mr. A. B. Cham- 

 plain, Entomologist, Pennsylvania Bureau of Plant Industry, 

 for the verification of the species mentioned in this paper, with 

 the exception of Brachynus cyanipennis, which was determined 

 by Mr. H. C. Fall. Thanks are also due to Mr. A. B. Gahan 

 of Washington, D. C, for the determination of the Hymenop- 

 terous egg parasites. 



