20 BULLETIN 417, U. S. DEPARTMENT OF AGRICULTURE. 



Anterior ventral plates of first to seventh abdominal segments not dilated 

 at center. 



Plates with a prominent notch in center, anteriorly and sometimes 

 posteriorly. 



(Southern and central United States) C. lugubre. 



Plates without notch in center anteriorly. 



Lateral plates somewhat circalar in form; ventral plate on 

 eighth abdominal segment somewhat rectangular, consider- 

 ably broader than long; middle posterior notch in above 

 plate obsolete or slightly marked — not as prominent as other 

 two posterior notches. . 



(Europe, introduced into Massachusetts). . . C. reticulatum. 

 Lateral plates elongate in form; ventral plates on eighth ab- 

 dominal segment nearly square, middle posterior notch well 

 marked and usually as prominent as other two posterior 

 notches. 



(Europe) C. auropunctatum. 



Caudal appendages long (2 mm. or more), slender, straight, not bent downward 

 beyond dorsal protuberance. 



Caudal appendages very long (2.5 mm.), slender and straight; dorsal 

 protuberance short, not prominent; posterior angles of seventh and 

 eighth abdominal tergites obtuse. 



(Eastern, southern, and central United States) C. externum. 



Caudal appendages long (2 mm.), slightly angled downward beyond 

 dorsal protuberance; posterior angles of anal segment and seventh 

 and eighth abdominal tergites rather sharply pointed. Larva robust. 



(Western and southern United States) C. peregrinator . 



Caudal appendages straight, long (2 mm.;, straight beyond dorsal pro- 

 tuberance; posterior angles of anal segment obtuse, almost truncate; 

 angles of tergites on seventh and eighth abdominal segments obtuse. 

 Larva long, slender. 



(Rocky Mountain section .and southwestern United States.) 



C. haydeni. 



GENERAL REMARKS. 



On the following pages will be found a consideration of each species 

 of Calosoma as it occurs in the foregoing table. The original descrip- 

 tion of the species is given, and also a statement concerning its dis- 

 tribution as secured from the literature and information furnished by 

 curators and entomologists in charge of museums or collections of 

 insects from all parts of the United States and Canada. The pub- 

 lished information concerning each species is summarized and the 

 results of the investigations which the writers have made dealing with 

 the feeding habits, reproduction, and life history, are included and a 

 bibliography of each species concerned. 



Following the species given in the table have been added Calosoma 

 aurocinctum. C. dietzii, C. maximowiczi, and C. splendidum, as these 

 have been examined by the writers and have been found in greater 

 or less numbers in the United States. They have not been placed 

 in the table, as no male specimens were available for study. 



MEASUREMENTS OF PUP.E. 



All measurements of pupae that are given in descriptions were 

 taken from the anterior margin of the prothorax to the end of the 

 anal segment, and the width was measured at the center of the first 

 abdominal segment. 



