2 PROCEEDINGS OF THE NATIONAX. MUSEUM. vol.64. 



from any other equally large region of the world, and that the 

 imagines of many of the American genera, for instance Gynaecomeloe^ 

 Cyst&odemus^ Megetra^ Phodaga^ Eupompha^ and Calospasta show 

 the most extraordinary and interesting features. 



The present writers consider it their good fortune to be able to 

 reveal the entire life history of the species Trncrcvnia sanguinipennis 

 and to describe its different stages, thus adding another complete 

 record of a North American Meloid to the one given by Riley. 



In presenting the results of the work the subject has been divided 

 into two coordinate parts, the first dealing with the biology of the 

 insect and the second with the anatomy and systematic description of 

 the different stages, especially the larval stages. J. B. Parker is 

 responsible for the first part, Adam G. Boving for the second. 



It has been considered appropriate to include in the second part 

 a brief account, with a key, of a classification, based on larval and 

 pupal characters, of the entire subfamily N emognathmae^ and, at 

 the end of the paper, to give an annotated bibliography of litera- 

 ture which refers to this account. 



The illustrations are all original and consist of photographs, taken 

 by J. B. Parker, and pen drawings by Adam G. Boving. 



The large and unique collection of material of Tricrania^ from 

 which the descriptions and figures have been made, has been collected 

 by J. B. Parker and has been donated by him to the collections of 

 Coleopterous larvae in the United States National Museum. 



The authors wish to extend their best thanks to Dr. E. A. Schwarz 

 and Mr. H. S. Barber, who kindly have aided them by valuable in- 

 formation and suggestions. 



PART 1. 



BIOLOGY. 



The beetle, Tricrania sanguinipennis Say, which belongs to the 

 family Meloidae, is in its larval stage a parasite of the solitary bee, 

 CoUetes I'ufithorax Swenk. The adult beetle is about ten millimeters 

 in length, black with blood-red wing covers and, being destitute of 

 true wings, is unable to fly. It passes the winter in the adult stage 

 deep down in the ground in the brood cell of its host. 



The nesting site of the host, where these observations were made, 

 is located on the grounds of the Catholic University of America, 

 Brookland, D. C., on a sloping bank facing south. The soil in which 

 the burrows of the bee are placed is a mixture of sand and clay and 

 the depth at which the host places her brood cells varies from eigh- 

 teen inches to two and one-half feet. The time of the emergence of 

 the adult beetle from the earth in the spring depends upon climatic 

 conditions in which temperature seems to be the chief factor. In 



