INVE.STKJATION OF I.IFK lilSIOKV. 



50 



Only neguliv(^ icsuhs were seemed riom these expeiinieiits. It is 

 probable that the tests should have been started earlier in June. 



Copulation. 



After emerging; from Jiihernatiou and feedinijj for a few days the 

 beetles oo])ulale, and e<i;<!; layin<>; is be<2;uu by the femah's. ]t is 

 necessary for them to be mated witli the males several times during 

 the season, or a large percentage of infertile eggs will be laid. The 

 record of a ])air of beetles which were kept in a jar for the third sum- 

 mer is interesting as it gives data on the frccpiency of copulation of 

 this species. The jar was examined once or twice a day when feeding 

 records or other notes wei-e being made. The pair was found in coitu 

 June 27, 29, 30, July 8, 9, 10, 14, 15, 17, 18, 19, 20, and 26. They 

 must have copulated at other times, because fertile eggs were laid on 

 the date of the first copulation noted. The female (le])osited 274 

 fertile eggs during the summer. Old beetles show a greater desire 

 to reproduce than young specimens. 



In several cases females have been ol)served to copulate late in the 

 summer, and no eggs were deposited tliereafter. In each of these 

 instances when the females were isolated in the spring without a male 

 no fertile eggs were deposited until after a male was added and copu- 

 lation took place. This indicates that tlie females can not be impreg- 

 nated in the fall and lay fertile eggs the following season without 

 furtlier mating. 



Reprodtttion. 



The highest number of eggs laid in ti single season by a female was 

 65.3. The next highest number recorded is 514. These records are 

 far above the average, as is shown in the following table: 



Table XIV. — Averaqe numbrr of eggs laid by frmalcs of Calosoma sycophanta diinng 



' 1908-njlO. 



The data for 1909 and 1910 are ])robably the most valuable, as a 

 larger number of specimens was under observation and fewer experi- 

 ments had to be conducted with material taken direct from Euro])e!iii 

 shi])ments. 



It wdll be noted that nearly one-third of the females did not deposit 

 eggs, and it should be stated that most of these were young beetles. 



