19111 



Notes on the Colorado Potato Beetle 



83 



supplementing what was previously indicated to be true in 

 1907. The evidence of course is gross in nature, for we did 

 not actually examine the mated females in any case for sperma- 

 tozoa, so that in the majority of cases, actual mating is open to 

 question. It is needless to say that this should have been done. 

 But in at least one case we are sure that both mating and repro- 

 duction occurred as fertile ova were deposited. 



In regard to the seasonal history in 1908, the second genera- 

 tion was obtained nearly a month earlier than that obtained 

 in 1907, so that there was ample time for a third generation. 

 The following table summarizes the generations reared in con- 

 finement. 



TABLE VIII. 

 Generations Reared in the Laboratory, Urbana, 



1908. 



Illinois, 



' Approximated; hatched 11 a. m., May 27. 



t Approximated; hatched 6:30 a. ra., July 7. 



LITERATURE REFERRED TO. 



1905. Stiles, Charles Wardell, Bull. No. 24, Hygienic Laboratory, Public Health 



and Marine-Hospital Service of the United States, Treasury Department, 

 Washington, D. C. 



1906. Tower, William Lawrence. An investigation of evolution in chrysomelid 



beetles of the genus Leptinotarsa. Publication No. 48, Carnegie Institu- 

 tion of Washington, Washington, D. C. 



1907. Girault, Alexandre Arsene and Arthur H. Rosenfeld. Biological notes on 



the Colorado potato beetle, Leptinotarsa decemlineata (Say), with 

 technical description of its stages. Psyche, Cambridge, Mass., XIV, pp. 

 45-57. 



1908. Girault, Alexandre Arsene. Further biological notes on the Colorado 



potato beetle, Leptinotarsa decemlineata (Say), including observations 

 on the number of generations and length of the period of oviposition. 

 Annals Ent. Society of America, Columbus, Ohio, I, pp. 155-17S. 



