16 BULLETIN 251, U. S. DEPARTMENT OF AGRICULTURE. 



sary for the latter to mate several times during the season, or a large 

 percentage of infertile eggs will be laid. Old beetles lay many more 

 eggs than young beetles. The highest number of eggs laid by a sin- 

 gle female in a season was 653. If an average is taken covering all 

 the beetles under observation for a single year, both young and old, 

 the rate of increase — that is, the average number of eggs deposited 

 by each female — will be about 100. The result of several years' work 

 in rearing beetles in confinement indicates that it is a common habit 

 of this species to oviposit sparingly, if at all, the first summer, and 

 to lay eggs freely the second season. If conditions are favorable the 

 first year, a number of eggs may be laid, while if they are unfavorable 

 oviposition is postponed until the second or third summer, as the case 

 may be. It sometimes happens that eggs are laid the first and third 

 summers, but not during the second ; at any rate, each female will lay 

 about an equal number of eggs, but the time they are deposited varies 

 greatly. 



.The data secured from field colonies indicates that the same con- 

 ditions apply. Two-thirds of the localities that were colonized with 

 beetle larva? have shown some reproduction the year following plant- 

 ing, while colonies where adults were liberated usually show much 

 larger increase. The jar records indicate that the old beetles multiply 

 seven times as fast as the young ones, and in the field, based on the 

 number of molt skins found in several colonies, the average is 10 to 

 1 in favor of the old beetles. 



HABITS OF FLIGHT. 



For a number of years it was believed that these beetles did not 

 fly. They were frequently seen in trees, and when disturbed would 

 fall to the ground without making any effort to use their wings. 

 A number of observations, however, prove that the species flies quite 

 freely, particularly early in the spring. There is at that time con- 

 siderable migration of the adults after they emerge from hiberna- 

 tion, and they undoubtedly seek localities where food is plentiful. 

 The fact that beetles have been found more than 20 miles outside the 

 area where they were colonized indicates that spread is accomplished 

 by flying or that the species was carried on vehicles or in some other 

 way. 



ATTRACTION OF ADULTS TO LIGHT. 



Several native species of Calosoma are attracted to strong light. 

 Although many observations have been made in eastern Massachu- 

 setts, where sycophanta was first colonized, and where the species is 

 abundant, it has never been taken at arc lights, and we have received 

 no record to that effect from various collectors in this vicinity. 

 Several specimens are reported to have been taken at electric lights 



