THE BEAjST LADYBIRD. 



9 



period extended from July 25 until September 2, a total of 40 days. 

 With other females this period covered from 35 to TO days. 



The life cycle from egg to adult and the periods of the stages by 

 days are given in Tables III and IV respectively. 



Table III. — Life cycle of Epilachna corrupta. 



Event. 



Eggs deposited. 

 Larvae hatched 

 Larvae molted. 

 Larvae molted. 



Bate. 



1916. 

 Aug. 10 

 Aug. 18 

 Aug. 21 

 Aug. 25 



Event. 



Larvae molted 



Larvae reached maturity 



Larvae pupated 



Adults developed 



Hate. 



1916. 

 Aug.- 30 

 Sept. 3 

 Sept. 5 

 Sept. 12 



Table IV.— Periods of stages of Epilachna corrupta. 



Instar. 



Egg period 



First larval stage period. .• 

 Second larval stage period 

 Third larval stage period. 



Number 

 of days. 



Instar. 



Fourth larval stage period 

 Pupal period 



Total 



Number 

 of days. 



The beetles which developed August 31 fed, without mating or 

 depositing eggs, until October 5, when they began hibernation. No- 

 vember 10. 1916, the cage was placed in the laboratory cellar and 

 removed to the open April 17, 1917. The beetles issued from hiberna- 

 tion June 15, 1917, and were then killed, closing the record. 



Records of egg-laying were obtained by confining single pairs of 

 beetles, immediately after mating and before the first eggs were 

 deposited, in small rearing jars. The beetles fed on bean leaves and 

 the eggs were removed as deposited and counted. The number of 

 eggs deposited by eight females of the first and second generations 

 were: 504, 552, 616, 636, 850, 942, 1,147, and 1,516, respectively, or an 

 average of 845 eggs to a single beetle. 



A detailed record of the female of one of these pairs of beetles, 

 which developed July 17, 1916. and mated July 22, is given in 

 Table V. 



Table V. — Egg-laying record of a single female of Epilachna corrupta in 1916. 



Date. 



1916 



July 25 



July 28 



July 29 



Aug. 1 



Aug. 3 



Aug. 5 



Aug. 6 



Aug. 9 



Aug. 11 



1916 



Aug. 15 



Aug. 18 



Aug. 21 



Aug. 2.3 



Aug. 26 



Aug. 28 



Sept. 2 



Total 



Number 



of eggs 



deposited. 



850 



152117°— 20— Bull. 843- 



