312 Trans. Acad. Sci. of St. Louis. 



6. AGE OF INSECTS WHEN MATING BEGAN. 



The object of these experiments was to ascertain at 

 how late or how early an age it was possible for mating 

 to occur. Had the insects been free to choose for them- 

 selves, perhaps they would not have waited so long, or 

 in some cases mated so soon, as the figures show. 



(a) Females. 



Age. No. Mating Age. No. Mating 



10 days 4 4 days _ 6 



9 days 5 3 days 5 



8 days 1 2 days 9 



7 days 2 1 day 4 



6 days 1 16-20 hours 9 



5 days 5 13-14 hours 5 



The table shows that the ages of the 56 females when 

 mating occurred varied from 13 hours to 10 days. Soule 

 found that it requires 16 hours out of the cocoon before 

 the female is ready to mate. This lot of material con- 

 tained five females which mated at an earlier age, 13 

 hours in one, and 14 hours in four instances, 



(b) Males. 



Age. No. Mating. Age. No. Mating. 

 12 days 1 3 days 3 



11 days 1 2 days li 



9 days 1 16-20 hours 5 



5 days 1 12-1.5 hours 5 



4 days 1 



The age at mating of these 33 males was found to vary 

 from 12 1-6 hours to 12 days. It will be seen that mat- 

 ing can occur in the male at a later age, and also at a 

 slightly earlier age, than in the female. 



