Vol. 1] Clausen. — Life-Histories of Calif ornmCoccinellidae. 295 



The record of 1550 eggs deposited within a period of slightly over 

 two months reported by B. K. Carnes^ tends strongly to bear out 

 this assumption. 



Rate of Oviposition 



Number 

 specimens 



C. calif ornica 10 



C. trifasciata 10 



H. convergens 11 



H. ambigua 8 



O. abdoniinalis 9 



O. ofulata 9 



A. bipuuctata 10 



C. sanguinea 10 26.0 7.0 318 121 201 



Life-History. — In a comparative study of life-histories it is 

 essential that due allowance be made for variations in conditions 

 under wliich the experiments are carried on in ease they are not 

 made sinniltaneously. The records of Hippodamia convergens, 

 Coccinella californica, Olla oculata and Adalia hipnnctata were 

 secured at Sacramento during the period from April 25 to August 

 20, 1913. Those of Coccinella trifasciata and Hippodamia am- 

 higua were secured at Berkeley during the spring of 1914, while 

 the life-history of Olla oculata was determined at Uplands during 

 May and June, 1914. As regards climatic conditions in the three 

 localities, Sacramento was considerably warmer than eitlier of 

 the other places, the temperature often reaching 105° F. and 

 occasionally higher. At Uplands the conditions more nearly ap- 

 proached those best suited to the maximum development of the 

 beetles, the average daily maximum temperature being approxi- 

 mately 85° to 90° F. At Berkeley the temperature was some- 

 what lower and the nights very cool. 



In computing the period lengths in the table given below, the 

 averages were taken of all individuals of each species and no 

 particular account made of individual variations. No very great 

 range was found in the egg stage, the longest period being 6.0 

 days for Coccinella trifasciata and the shortest 4.3 days for Olla 

 oculata. The first larval stage required from 3.8 to 5.7 days, the 

 members of the genus Coccinella apparently requiring longer 



1 E. K. Carnes, Monthly Bulletin, Calif. Hort. Com., Sept., 1912, p. 820. 



