34 



MASS. EXPERIMENT STATION BULLETIN 189. 



Table VI. — Length of Life of Male and Female Moths in Captivity 

 First Generation. 



Average length of life: male moths, 13.74 days; female moths, 18.26 days. 

 Maximum length of life: male moths, 35 days; female moths, 28 days. 

 Minimum length of life: male moths, 3 days; female moths, 6 days. 



It is believed that the duration of adult life, as well as the period before 

 and during oviposition, depends considerably upon the accessibility of 

 the opposite sex, temperature conditions, and the facilities afforded for 

 oviposition. Nevertheless, the data given above were secured under as 

 near natural conditions as could be arranged in cages, and the averages 

 are believed to represent very closely the actual duration of adult periods 

 in the field. These figures are important, showing as they do the com- 

 paratively long period during which the adults deposit their eggs. 



Life Cycle Summary. 

 A complete life cycle is here considered to be the total period elapsing 

 from the deposition of eggs of one generation to the time of deposition 

 of eggs of the next generation. Therefore the average duration of the 

 life cycle of the fii-st generation of the European corn borer during 1918 

 was 63 days, with a maximum of 85 and a minimum of 48 days, as shown 

 by the following table : — 



Table VII. — Life Cycle Summary of First Generation. 



