266 University of California Pnhlications. [Extomology 



Egg-Laying Eecords — Eippodamia convergens Guer. — (Continued) 

 Sacramento, 1913 Berkeley, 1914 

 Date 12 3 4 5 6 Date 7 8 9 10 11 



June 9 18 21 May 1 9 D 



10 19 16 2 22 



11 27 14 3 23 



12 22 7 4 16 



13 26 13 5 D 8 



14 12 22 6 26 



15 7 8 7 27 



16 6 8 5 



17 21 14 9 11 



18 D 16 10 



19 20 D 20 11 14 



20 6 22 12 12 



21 5 13 23 



99 



21 14 



23 15 D 



24 D 9 16 



25 D 17 



Total 425 466 94 141 115 234 371 609 176 280 326 



Average 11.4 13.7 5.8 11.7 4.6 6.1 9.7 12.1 5.8 9.3 9.3 



Lifc-Historij. — Under normal summer conditions in the Sacra- 

 mento Valley the life-cycle of this species from egg to adult is 

 accomplished within a period of approximately four weeks. The 

 variation in this respect of eight individuals from the same parent 

 extended from 27 to 34 days, averaging 28.75 days. This period 

 was divided as follows : egg stage, 5 days ; first larval, 3.9 days ; 

 second larval, 3.6 days ; third larval, 2.3 days ; fourth larval, 6.5 

 days ; and the pupal stage, 7.5 days. The period of incubation 

 of the eggs varied only a few hours among the eight individuals, 

 while the variation in the first larval stage was from three to 

 eight days, the second larval from two to four days, the third 

 larval from two to three days, the fourth larval from six to eight 

 days, and the pupal stage from seven to eight days. It will be 

 seen that with few exceptions the period intervening between 

 moults was quite constant and distinct for each stage. 



