FURTHER OBSERVATIONS ON COPULATION AND 

 OVIPOSITION IN SAMIA CECROPIA LINN.* 



Phil Rau. 



During the spring of 1910 a study of the duration of 

 life of Samia ceropia Linn, was in progress. In connec- 

 tion with this it was convenient to gather a large amount 

 of data to supplement the observations published last 

 year.^ 



The 205 cocoons came from the same locality as before. 

 They were kept under wire dish-covers, and the insects 

 emerged at intervals from April 13 to June 17. 



I. Obsebvations on Copulation. 



1. LENGTH OF TIME SPENT IN COPULO. 



Mating usually commenced between midnight and 

 morning, and with very few exceptions, ended at those 

 hours on the following daj^ These hours were such as to 

 make exact observations impossible. 



Tabulation shows that the time spent in copulo varies 

 from 10 to 48 hours, with one case of 72, the average be- 

 ing 21 hours. This agrees exactly with the observations 

 of the previous year. 



Two cases occurred which were strikingly exceptional. 

 One pair remained in copulo without separation for 72 

 hours and then mated three times after that, the last 

 time remaining in copulo 10 hours. This was the most 

 extreme case of remating observed. The other pair also 



*Read before the EBtomological Section, October 27, 1910, and pre- 

 sented by title to The Academy of Science of St. Louis, April 8, 1911. 

 ' Trans. Acad. Sci. St. Louis, 19 : 21-48. 1910. 



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