490 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 8 



days for C. trifasciata. In no case were more than six days required 

 for incubation. Almost invariably the eggs comprising a cluster all 

 hatched within a few hours. The first larval stage varied from 3.3 

 days for 0. ahdominalis to 5.7 days in the case of C. californica. A 

 single larva of C. californica required ten days, but apparently was not 

 normal and died shortly after pupation. The second larval stage was 

 found to be uniformly shorter than the first, the variation being from 

 2.3 days for 0. ahdominalis to 4.7 days for H. ambigua. Nine larvae of 

 H. ambigua, three of C. californica, and one of H. convergens required 

 only two days for this stage, while one specimen each of H. ambigua 

 and 0. oculata required six days. The third stage was of approxi- 

 mately the same length as the second, with the exception of H. con- 

 vergens, in which case the period was much shorter. Two individuals 

 of 0. oculata required five days. The fourth stage was considerably 

 longer than those preceding it, the range being from 4.7 days in the 

 case of 0. abdominalis to 7.4 days for C. trifasciata. The greatest 

 variation, however, was found in the pupal stage, where' 3.5 days were 

 required by 0. abdominalis and 8.0 for H. ambigua. The totals of the 

 successive stages gave a minimum of 21.0 days for 0. abdominalis and 

 a maximum of 33.2 days for H. ambigua. 



Duration of Different Stage in Days 



Species 



No. of 



Specimens 



Egg 

 Stage 



First 



Larval 



Second 



Stages. 

 Third 



Fourtli 



Pupal 

 Stage 



Total 



C. cdifornica Mann 



13 



5.4 



5.7 



3.3 



3.4 



6.8 



4.5 



29.1 





12 



6.0 



5.3 



4.2 



3.3 



7.4 



3.7 



31.8 





8 



5.0 



3.9 



3.6 



2.3 



6.5 



7.5 



28.8 





10 



5.5 



3.8 



4.7 



3.6 



7.3 



8.0 



33.2 



0. abdominalis Say 



14 



4.2 



3.3 



2.3 



2.8 



4.7 



3.5 



21.0 



0. oculata Fabr 



11 



5.0 



4.6 



4.5 



4.2 



7.0 



5.1 



30.2 





7 



5.0 



4.6 



2.9 



3.0 



5.6 



6.0 



26.7 





10 



5.3 



4.5 



3.7 



3.2 



4.9 



4.2 



25.3 



Feeding Records 



The average number of aphids eaten by a larva during the entire 

 period ranged from 216 for C. sanguinea to 475 in the case of C. cali- 

 fornica. One individual of the former species came to maturity after 

 consuming 147 aphids, while one larva of C. californica required 580, 

 this being the maximum for a single individual. 



Daily feeding records of the adult beetles covering a fifteen-day 

 period were secured with the exception of H. convergens, the records of 

 which extend over only eight days. The maximum period average 



