THE GENUS CALOSOMA. 5 



taming 4 to 6 inches of earth usually descend to or near the bottom to 

 perform this function. Infertile females which were denied males, 

 frequently deposited large numbers of small eggs on the surface of 

 the earth, seemingly not wishing to leave the surface and lose any 

 possible chance of mating. 



The eggs hatch in from 3 to 15 days, depending upon the tempera- 

 ture and season of the year, and to a slight extent upon the species. 

 The longest time is required for those species that deposit many of 

 their eggs late in May and during the first part of June. G. calidum 

 Fab. and C. reticulatum Fab. emerge from hibernation early in the 

 spring and the number of days spent in the egg stage is greater than 

 with other species, C. sycophanta for example, whose normal period 

 of reproduction is from June 10 to July 31. The period in the egg 

 stage is much shorter as the season advances. The eggs of V. 

 sycophanta often hatch in three days during very hot July weather. 



After hatching, the young larvae, which are white at first, rapidly 

 grow darker in color. They remain in the location where the eggs 

 were deposited until they reach their permanent color which varies 

 from brown to black, and in from one to three hours begin to move 

 toward the surface of the ground. When confined in jars, if food is 

 not found readily, the more active specimens frequently feed on those 

 that are weaker or less active. 



In New England different species of Calosoma larvae hatch from 

 May 20 to August 15, and feed until mature upon various kinds of 

 lepidopterous larvae and pupae. During this period they molt twice, 

 the time in each stage averaging as follows: First stage 3 to 6 days, 

 second stage 4 to 7 days, and third stage 9 to 15 days. When 

 full-grown the larva burrows from 8 to 10 inches into the earth if 

 it is rather soft, and if not, a shorter distance is travelled. From 

 4 to 7 days are required to prepare a cavity for pupation. The walls 

 are made compact by the movements of the larva within the cell. 

 After the larva has gradually contracted and has become shorter and 

 thicker, the skin is cast and pupation takes place. 



The pupa always lies in the cavity resting partly or wholly on the 

 stiff hairs which are present on the dorsal side of the first five ab- 

 dominal segments. From 10 to 15 days are ordinarily passed in this 

 stage. The pupa is at first creamy-white, but the appendages soon 

 begin to assume the color of the adult insect. 



The adult issue.s during the latter half of July or in the month of 

 August, and some species soon seek the surface of the ground and 

 begin to search for food. C. calidum and C. reticulatum possess this 

 habit. They feed late in the summer of the year in which they are 

 larvae and pupae. Adults of C. sycophanta, C. frigidum Kirby, and 

 other species remain in the pupal cavity until the following spring 

 before emerging and taking food. 



The longevity of the adults of different species apparently does 

 not vary greatly, and under field conditions they undoubtedly 

 survive three years or more. Adults of some of the species may live 

 four years or more, and under conditions where species could be 

 closely observed one female, C. sycophanta, has lived for more than 

 four years. The reproduction of the adults in various years has a 

 direct bearing on the age limit. If the beetles reproduce freely dur- 

 ing the first and second years of their existence, they usually die at 

 the end of that time. 



