STUDIES: ON THE LIFE) HISTORY AND | BIOLOGY ee 
PERILLUS BIOCULATUS FABRICIUS, INCLUDING 
OBSERVATIONS ON THE NATURE. OF 
Tae COLOR EAE a RIN: 
(Heteroptera, Pentatomidae ) 
By Harry H. Knight 
The writer’s attention was first directed to Perillus bioculatus when 
specimens were found feeding upon the Colorado potato beetle, dur- 
ing July, 1913, in Genesee county, N. Y. Upon finding a red and 
black bug mating with a white and black individual, the idea imme- 
diately occurred that here was a fine opportunity to study color inheri- 
tance in an insect. Studies on the life history were at once begun, 
and the writer has given more or less time each year since to the 
rearing of this Pentatomid, except for the years 1917 and 1918. 
After the close of the war, and with the writer’s removal to Minnesota 
in 1919, the study of Perillus was begun anew when the species was 
found fairly abundant in the vicinity of St.. Paul. The first three 
years, or from 1913 to 1915 inclusive, were given over to breeding 
experiments and the study of color inheritance in the bugs. By the 
close of 1915 it became quite evident that the color forms could not 
be segregated by ordinary methods of breeding, but that individual 
colors were more dependent on the external conditions under which 
the bugs were reared. The season of 1916 was given over to a study 
of the factors influencing the color pattern of the bugs. The work 
on Perillus at Minnesota during the last three years has been chiefly 
on the nature of color, as well as a continuation of study on the factors 
influencing the color in individual bugs. 
Since the double-eyed soldier-bug is of economic importance in 
the control of the Colorado potato beetle, the present paper is given 
over largely to an account of the life history and biology of the species 
with data on its importance as a beneficial insect. ; 
1 Published, with the approval of the Director, as paper No. 303 of the Journal Series 
of the Minnesota Agricultural Experiment Station. 
