INVESTIGATION OF LIFE HISTORY. 47 



On March 4, 1908, two jars were removed from the cellar and kept 

 in the laboratory at room temperature. In one of these the fully 

 formed beetle could be seen in a cavity at the side of the jar. On 

 April 13 this beetle, which proved to be a female, emerged and fed, and 

 on April 16 the remaining beetle, also a female, came to the surface 

 and began feeding. 



The other two jars were not removed until June 9. A dead beetle 

 which had previously emerged was found on the surface of the ground 

 in one of them, while in the other a live male was found in the cavity. 



To check these experiments, three jars, each containing a pupa, 

 were placed in cold storage September 7, 1907. One pupa had trans- 

 formed in a jelly glass 1J inches below the surface of the earth. This 

 glass was put into a battery jar containing 1 inch of earth and enough 

 more was added around the sides of the jelly glass to make the earth 

 level in both jars. The second pupa had transformed in earth, in a 

 jelly glass, and the third pupa, in a battery jar, was located in a 

 cavity 2 inches below the surface of the earth. On June 5, 1908, all 

 the jars were removed from cold storage. The pupa in each case 

 was dead. In one of the glasses, and in the battery jar, the earth 

 was very dry. The death of the pupae was due presumably to the 

 sudden reduction in temperature to about 28° F.,no rise in temperature 

 being noted during the entire period of storage. 



These experiments indicate that the Calosoma beetles normally 

 emerge from the pupa in the fall and hibernate in the adult form dur- 

 ing the winter, as this was the case in the first set of experiments, even 

 though the temperature was reduced considerably below normal. 



Length of Time Spent by Calosoma sycophanta in the Pupal Stage. 



It is somewhat difficult to ascertain the exact length of time spent 

 in the pupal stage, for the reason that several days elapse from the 

 time the larva stops feeding until actual pupation takes place. 



In the season of 1910 notes were made on eight larvae that pupated 

 in jars of earth in such positions that their movements could be 

 observed. The length of time from cessation of feeding until pupation 

 actually took place was from 7 to 15 days, the average time being 

 10J days. In one case a larva pupated on July 27, 1908. On August 

 2 the legs were becoming darker in color, and on August 4 a female 

 beetle emerged. The elytra were still soft, and some little time was 

 required for the beetle to become fully developed and active. A few 

 days later it entered the ground and formed a cavity, where it remained 

 for hibernation. In two other cases from 10 to 11 days were required 

 for the pupa to pass through that stage. 



On August 20, 1909, a fully formed pupa was found in a cell under 

 a board in one of the out-of-doors cages, and careful notes were made 



