Rau — Longevity in Saturniid Moths. 5 



Longevity. 



In 1910-11, observations were made on the longevity 

 of about 900 of these moths, and the mean duration of 

 life of the different lots were assembled in Table 1 (loc. 

 cit., p. 183). In the present work more than twice this 

 number were employed in the continued search for new 

 factors influencing the length of life. In like manner we 

 have brought together in the table below the means for 

 all of the lots of material herein considered. This table 

 will frequently be referred to. (See Table 1.) 



PHILOSAMIA CYNTHIA. 



Two lots of Cynthia cocoons were obtained for this 

 purpose, one lot from Philadelphia, which yielded 208 

 insects, and the other from New York City, which gave 

 forth 151 adults in good condition for these observa- 

 tions. Table 2 below gives the details of the duration of 

 life of the Philadelphia lot. The cocoons were shipped 

 to St. Louis during the winter and kept out of doors un- 

 til spring when they emerged between June 7 and 28. 

 (See Table 2.) 



Table 3 presents the details of the longevity of the 

 New York lot. The cocoons arrived here during the 

 winter, were likewise kept out of doors in the trees until 

 spring, and 151 imagines emerged between May 30 and 

 June 25. (See Table 3.) 



In comparing Tables 2 and 3 we find the New York 

 lot to be slightly the longer lived throughout. In these 

 two tables we find practically no difference between the 

 mated and unmated males, showing that here at least 

 mating does not perceptibly alter the life of the male. 

 Among the females, however, the unmated individuals 

 lived longer than the mated ones. A comparison of all 

 males with all females shows the females as a class to 

 be longer lived. 



