"Vol. 1] Clausen. — Life-Histories of California Coccinellidae. 293 



Comparative Kecords 

 Time from Emergence to Mating and Egg-laying. — Complete 

 data in regard to these periods were secured for only five of the 

 species under investigation. In the case of Hippoclamia con- 

 vergens and Olla oeulata, records were secured only in regard 

 to the time from mating to egg-laying, and none whatever in 

 the case of Coccinella trifasciata. The periods varied only to a 

 comparatively slight extent between the different species. From 

 emergence to mating the usual intervening period was one to 

 three days, the averages ranging from 1.6 days in the case of 

 Adalia hipunctata to 2.7 days for Coccinella californiea. From 

 mating to oviposition a corresponding variation occui-red, the 

 shortest time being seven days for Cycloneda sanguinea and Olla 

 abdominedis. The general averages for the different species 

 varied from 8.6 for Olla oeulata to 11.9 days for Coccinella 

 californiea. 



Emergence to Mating and Egg-Laying 



Emergence to mating days Mating to egg-laying days 



Number , ^ v, , ^^ — '- ^ 



s])ecimens Max. Min. Aver, Max. Mill. Aver. 



Coccinella californiea 10 3.0 2.0 2.7 14.0 10.0 11.9 



Hippodamia convergens.. 6 .... .... .... 13.0 8.0 10.5 



H. ambigua 9 3.0 1.0 1.7 11.0 8.0 9.6 



Olla abdominalis 9 3.0 1.0 1.7 10.0 7.0 8.6 



O. oeulata 9 13.0 8.0 10.7 



Adalia bipunctata 10 2.0 1.0 1.6 11.0 8.0 9.6 



Cycloneda sanguinea 10 3.0 1.0 1.9 12.0 7.0 10.1 



Periods of Oviposition. — The period over which egg-laying 

 will extend is largely dependent upon the conditions under which 

 the individuals exist. Egg-laying normally takes place daily, 

 with an occasional exception, approximately two weeks after 

 emergence until death. Inasmuch as all the experiments upon 

 this point were not conducted under similar conditions the re- 

 sults will naturally vary to a greater or less degree. 



The maximum number of days included in the oviposition 

 period w^as found to be 59 in the case of Hippodamia amhigua, 

 Coccinella californiea was second with 51, and Adalia 'bipunctata 

 last with 39 days. The average number of days for the indi- 

 viduals of each species was 48.1 for H. ambigua, 35.4 for Olla 

 oeulata and last, A. bipunctata with 28.2 days to its credit. 



