121 
ANNUAL ADDRESS 
Observations on the Phenomena of Heredity in the 
Ladybeetle, Coelophora Inaequalis (Fabricius). 
BY P. H, TIMBERLAKE. 
(Presented at the meeting of December 1, 1921.) 
It has long been known that certain species of ladybeetles 
of the family Coccinellidae exhibit marked colorational dimor- 
phism or even polymorphism. Among North American species 
Adalia bipunctata (Linnaeus) and Olla abdominalis (Say) are 
known to have a predominantly black phase besides the much 
more abundant paler form. Mr. A. F. Burgess appears to 
have been the first American entomologist to make observa- 
tions on the phases of Coccinellidae, and in some breeding 
experiments that he conducted with Adalia bipunctata found 
that the black and normal phases, when mated together, pro- 
duced both phases again not only in the first, but in the second 
generation.* 
In experiments carried on at Whittier, California, in 1912, 
and again in 1915 at Salt Lake City, Utah (using beetles, how- 
ever, from Brownsville, Texas, collected by Mr. M. M. High), 
I found a similar set of phenomena in regard to the heredity 
of the black and normal phases of Olla abdominalis. Through- 
out the experiments a perfect segregation of the phases was 
obtained, but there were no other evidences of Mendelian inheri- 
tance in respect to the dominance of one phase over the other, 
or in the sequence and proportions of the phases when interbred. 
It even seemed next to impossible to get pure stock of the 
black phase by breeding, for when this phase was mated to- 
gether for two or more successive generations, the offspring 
was quite as apt to belong to the normal as to the black phase. 
In 1912, I had the opportunity of experimenting with an 
Oriental Coccinellid Cheilomenes sex-maculata (Fabricius), 
which was brought by Mr. R. S. Woglum from India to the 
United States. Of this species I received originally eight 
females and one male which were all of the normal se.r- 
maculata phase. As soon as they began to lay eggs the females 
Proc. Haw. Ent. Soc., V, No. 1, October, 1922. 
*U. S. Dept. Agric. Bur. Ent. Bull. 17, pp. 59, 60, 1898. 
