Ran — Longevity in Saturniid Moths. 69 



PEOBABLE TWO-BEOODEDNESS OF T. POLYPHEMUS. 



All of our Polyphemus adults — and a great number 

 we had from several localities — emerged in May or June 

 and one group emerged in good numbers as early as the 

 last of April. Therefore we were much surprised to take 

 a female on August 11, 1912, which was in good condition. 

 The fact that she laid fertile eggs proves that there must 

 also have been males lurking somewhere this late in the 

 season. With what we know of the longevity of this spe- 

 cies, it is impossible to believe this to be one which had 

 emerged in the spring. This species may possibly be 

 double-brooded. 



On July 30, 1913, a male Polyphemus was brought to 

 me, apparently in good condition. 



INFEBTILITY OF POLYPHEMUS EGGS. 



Since the Polyphemus were seldom seen in copulo, it 

 was thought that possibly mating might occur for such 

 brief periods that it was only by chance that they 

 could be seen. To test this point, all of the eggs of 25 

 females of this species which had had ample opportunity 

 for mating were cared for until long past hatching time 

 to see whether, perchance, fertilization had occurred un- 

 noticed. But they all soon shrivelled, and none at all 

 ever hatched. This strongly indicates that mating does 

 not occur for brief intervals on the sly, and also that 

 these females do not lay parthenogenetic eggs. 



CEOSSINGS. 



On June 3 a female Polyphemus mated with a male 

 Cecropia from 6 a. m. to 6 p. m. The female died the next 

 day without ovipositing. 



On May 9 a 10-day-old female Polyphemus mated with 

 a male Cecropia. It lived for a few days afterward, and 

 deposited 4 eggs, which proved infertile. 



After we found it impossible to get the Prometheas to 



