a single larva can survive in each twig. This congestion in num- 

 bers and restricted distribution would commonly be taken to in- 

 dicate a spirit of mutual toleration bordering on gregariousness. 

 In this case, however, if adults of both sexes are confined at all 

 closely together they will, regardless of sex, fall upon each oth- 

 er, amputating antennae and legs with a savagery like that of 

 the most bloodthirsty quadruped, and this vicious disposition 

 is, in fact, one of the greatest obstacles to the close study of these 

 insects in confinement. 



These studies are based very largely on the acute and un- 

 tiring observations of Mr. E. S. G. Titus, formerly Assistant to 

 the State Entomologist of Illinois and now an assistant in the 

 Division of Entomology of the United States Department of Ag- 

 riculture. The species was from the first regarded by him as 

 probably new, and later, in connection with my own studies of 

 insects infesting shade and ornamental trees, specimens were 

 submitted to Dr. L. 0. Howard for identification, which revealed 

 the fact that it was not represented in the collections of the 

 Department of Agriculture, or in those of the United States 

 National Museum. As Mr. F. H. Chittenden, of the Division of 

 Entomology of the Department of Agriculture, had already col- 

 lected considerable material for a study of the genus Oberea, he 

 was invited to describe the species, and his description of the 

 adult follows, together with a table prepared by him showing 

 the relations of the species in the genus. 



DESCRIPTION OF THE SPECIES. 



The Adult. 



"While studying reared material of the genus Oberea, and 

 referring to published accounts of the species, it was observed 

 that in many references to economic literature the raspberry 

 cane-borer was called Oberea tripunctata Fabr. as well as 0. tri- 

 punctata Swed. It has been conceded by Horn and others that 

 the former name is synonymous with 0. bimaculata Oliv., which, 

 the writer is convinced, is quite distinct from 0. tripunctata of 

 Swederus. We have recently had considerable correspondence 



