58 NINETEENTH REPORT STATE ENTOMOLOGIST OF MINNESOTA—IQ22 
a few seconds between eggs. The eggs are deposited 1 ina double row, 
the sides of the eggs in contact and glued together. *In placing the 
eggs the female alternates in such a way that one row never has but 
one egg more than the other. The eggs are yellow when first laid 
but begin turning brown almost immediately; within ten minutes they 
are blackish and by the end of an hour have attained their permanent, 
deep black color. The average female lays a cluster of eggs each day 
for the first five to seven days of egg production, following which 
she usually begins to skip alternate days, while the last egg masses 
deposited may be separated by periods of four or five days. Egg 
masses of from 24 to 30 eggs are produced as the result of a female 
going more than three days without laying. 
Females that are kept segregated from the males frequently deposit 
infertile eggs. Invariably such eggs are pale in color when laid and 
never change to black. Females that are isolated from the males will 
continue laying fertile eggs for several days, but in the case of several 
such bugs it has been observed that after about two weeks, and the 
deposition of several egg masses, the last eggs to be laid remain pale, 
and in most cases never hatch. From this it would seem that the 
spermatozoa had all been used, and the unfertilized eggs without such 
stimulus remain pale in color. This observation has been made so 
many times that it appears quite certain that the act of fertilization 
produces changes in the egg which result in the black color. Of 
perhaps three dozen pale egg masses observed, only one was found 
to hatch part of the es 
below under incubation. 
Fecundity of the females. In Table 1 is recorded the egg laying per- 
formance of nine female bugs selected as the most successful layers 
among fourteen that were started during August, 1913. The number 
of eggs laid in a mass is shown under the different dates as deposited, 
and where two or three egg masses were laid on a single day, the 
number of eggs in each mass is indicated. The death of a female 
is indicated with “D” under the date when found dead. The bugs were 
selected from reared lots, and isolated as pairs in cages, the records 
showing the total number of eggs laid by each female. The males 
lived as long as the females except in pair No. 5, of which the male 
died August 29, while male No. 8 died August 16. The highest number 
of eggs produced was 264 by femaie No. 8, while the lowest was 62 
by bug No. 1, the latter dying somewhat prematurely. Averaging the 
total number of eggs laid by these nine female bugs, it is found that 
the average per individual is 144 eggs. 
5 
ges. This particular egg mass is discussed 
