32 
PLANT-BUGS INJURIOUS TO COTTON BOLLS. 
Two points of importance are brought out by the data given in 
Table VII. First, it is evident that the duration of fertility after 
isolation does not cover the normal egg-laying period of the female. 
Second, the end of the period of fertility in the female is not well 
marked and a considerable period may elapse between the deposition 
of the first infertile egg and of the last fertile egg. 
PROPORTION OF SEXES. 
While observations on a small scale indicated a preponderance of 
the number of females over the number of males, the final and most 
conclusive observation as well as the totals show that the two sexes 
occur in about equal abundance. The difference in favor of the 
female sex shown in the totals is less than 2 per cent over an equal 
division, a difference which might occur in slbj arbitrarily chosen 
series from a large number of specimens including exactly one-half 
of each sex. 
Table VIII. — Proportion of sexes of the conchuela. 
When collected. 
Where collected. 
Number of 
males. 
Number of 
females. 
Total. 
September, 1904. . . 
Julv 11, 1905 
Tlahualilo,Durango, Mexico. 
do 
7 
17 
247 
12 
25 
19 
42 
July 12, 1905 
do 
253 500 
Total 
271 
290 
561 
LONGEVITY. 
Adults collected in the field. — Provided that an abundance of food 
is available, the length of life of the adults when protected from 
their natural enemies is dependent upon the season of the year in 
which the insects reach maturity. The following tabulations 
summarize the data concerning this point in the life history of the 
conchuela derived from the laboratory records. 
Table IX. — Summary of records of longevity of adults of the conchuela collected in cotton 
fields. 
Number of 
specimens. 
Where collected. 
When col- 
lected. 
Maximum 
longevity. 
(Days.) 
A verage 
longevity. 
(Days.) 
8 
14 
5 
9 
6 
2 

11 
Tlahualilo, Durango, Mexico 
Barstow, Tex 
1905. 
July 6-10 
Aug. 12 
Sept. 12 
Sept. 19 
Oct. 13 
9 
142 
83 
29 
6 91+ 
6 67 + 
79 
"09" 
"c67+' 
9 
71 
29 
17 
53 
6 67+ 
37 
"9" 
"53+ 
do 
Clarendon, Tex 
a Apparently parasitized by Tachinid fly but no parasite emerged from body of supposed host. 
6 In hibernation test December 1; all alive December 19; all dead March 8, 1906. 
c Alive January 17, 1906, in hibernation cage; dead March 8, making 98+, but to keep on same 
other specimens the record was included only up to December 19, 1905. 
