Vol. 1] Clausen. — Life-Histories of Calif ovnia Coccinellidae. 253 



In the experiments conducted at Sacramento the hop aphis 

 {Phorodon hiimuli) was used for all feeding purposes, unless the 

 contrary is stated. At Berkeley and Riverside the rose aphis 

 {MacrosipJnnn rosae) was used. More difficulty was here experi- 

 enced in securing a standard size than was the case with the hop 

 aphis. As nearly as possible iiidividuals approximately two- 

 thirds the maximum size of the adults of the species were used, in 

 order to obviate the possibility of the production of young during 

 the day. 



In the life-history experiments, observations were ordinarily 

 made once each day and the cast larval skins removed. The moult 

 was credited in each ease to the day upon which the exuviura was 

 removed, as it was impracticable to make observations corre- 

 sponding to fractional days. The date of pupation was recorded 

 upon the day during which the median dorsal split appeared in 

 the fourth larval skin, even though this may have taken place 

 several days after the larva, having ceased feeding, attached 

 itself to some solid base, and assumed the general appearance and 

 form of the pupa. 



In order to secure complete egg records it was found neces- 

 sary to make the count and remove all eggs three times each day, 

 because of the strong tendency of the females at times to devour 

 their own eggs, even though an adequate supply of food was 

 present at all times. 



In the tabulations as given in this paper the following sym- 

 bols have been used to designate certain things. They are as 

 follows : L = Eggs deposited 



H = Hatched 



* = Moulted, or death of male 

 P = Pupated 

 E = Emerged 

 M = Mated 

 D = Dead 

 C = From cold storage 



Coccinella californica Mann. 



The individuals of this species are the largest in size of any 

 of the common California coccinellids, the fully developed larvae 

 measuring 10.2 mm. and the adult beetles approximately 8.0 mm. 

 The elytra of the adult normally exhibit no markings of any 

 kind, yet specimens have been found which exhibited spots of 



