INVESTIGATION OF LIFE HISTORY. 



69 



Table XVIII. — Longevity of 10 pairs of Calosoma sycophanta reared during the summer 



of 1908. 



No. 



Male. 



Fe- 



Eggs laid 

 in— 



Hibernation, 1910-11. 



Remarks. 







1909 



1910 



1911 





1735 

 173G 



1743 

 1771 





1 

 1 



1 



1 

 1 

 1 

 1 

 2 



1 





 



38 

 

 

 

 

 



156 



179 

 18 





 

 

 310 

 345 

 n 



290 



"""26" 



53 

 25 

 142 



Male entered Aug. 20, 1910, died. 

 Male and female entered July 

 28, 1910. 



Male and female entered July 



26, 1910. 

 do 



Female died Aug. 16, 1910. 

 Male died in hibernation in 1909, 



replaced; beetles died Aug., 



1911. 

 Female died July 31, 1911; male 



died Aug. 12, 1911. 

 Female died July 6, 1911; male 



1775 



do 



died July 31, 1911. 

 Male died July 5, 1911; female 



2705 





died July 11, 1911. 

 Female died Aug. 3, 1910; male 



2728 







died Sept. 2, 1910. 

 Male died June 21, 1909, replaced ; 



2729 

 12775 



332 



1 male and 2 females entered 

 July 28, 1910; male died. 



female died Aug. 14, 1910. 

 Two males added in 1909; one 



died July 8, 1910; one female 



died Aug., 1911. 2 

 Female died July 10, 1910. 











1 Age of male in this experiment not recorded. 



2 Second female deposited eggs August 12, 1911. 



Of the females listed in the table, 3 lived two summers, 5 died at the 

 end of the third summer, and one is still living and ovipositing (Aug. 

 12, 1911). None of them laid eggs more than two seasons and some 

 of them only one. 



Of 10 males 4 died at the end of the first year or during the hiber- 

 nation period following it, 2 died the second summer, and 4 the third 

 summer. 



These experiments indicate that, on the average, there is little dif- 

 ference in the length of life of the males and females. The latter com- 

 monly live two summers, and if the full number of eggs has not been 

 deposited at the end of that time they continue to live until this 

 result is accomplished, provided a sufficient food supply is available. 



RELATION OF CALOSOMA SYCOPHANTA TO NATIVE SPECIES OF THE SAME 



GENUS. 



The native species most closely resembling Calosoma sycophanta are 

 G. scrutator Fab. and C. willcoxi Lee. 



C. scrutator is more common in the central and southern part of the 

 United States, and occurs somewhat rarely in the latitude of Boston, 

 Mass., and farther north. It is a larger species than O. sycophanta; 

 the green elytra are margined with a purplish band, and the thorax 

 has a shiny copper-colored margin on all sides. These color markings 

 distinguish it from C. sycophanta. 



C. willcoxi is also a southern species but is occasionally found in 

 Massachusetts and might be mistaken for a small specimen of C. 

 sycophanta. It differs, however, in having color markings on the 

 thorax and elytra similar to C. scrutator. 



