PINK BOLLWORM OF COTTON IN MEXICO. 
15 
Table V. — Number of pink bollworm larvse, found in single and double seed of cotton 
picked at different dates. 
Date 
picked. 
Date 
exam- 
ined. 
Double seed. 
Single seed. 
Weight of sample. 
Number 
double 
seed. 
Number 
of lar- 
vae in 
double 
seed. 
Per cent 
of total 
larvae 
in double 
seed. 
Number 
single 
. seed 
damaged. 
Number 
of larvas 
in single 
seed. 
Per cent 
of total 
larvae 
in single 
seed. 
First picking: 
J pound 
1919. 
Aug. 4 
Aug. 6 
Sept. 23 
Oct. 16 
Nov. 2 
1918. 
Dec. 3 
Dec. 10 
1919. 
O.ct. 10 
Oct. 8 
Oct. 22 
Oct. — 
Oct. — 
Mar. 30 
Mar. 20 

10 

30 
234 
106 
36 



29 
30 
95 
26 



58 
56.6 
30 
33 
38 
108 
150 
121 
467 
715 
597 
2 
1 
3 
21 
23 
250 
53 
100 
100 
100 
Second picking: 
41 
43.4 
Third picking: 
70 
67 
1 One pupa in lint, not counted in above. 
2 Two pupae in lint, not counted in above. 
This table shows that no double seed was found in cotton from the 
first picking, that 57.3 per cent of the larvse were found in double 
seed from the second picking, and that the percentage fell to 31.5 
in the third picking. It is probable, however, that occasional double 
seeds are formed during August and September or in the first picking. 
Taking an average of these figures and reducing them to a 1-pound 
basis, the number of larvae per bale present in the seed from the 
different pickings can be calculated. It is thought that no live larvae 
pass through the gins in the lint, and that many of the larvae in the 
seed are driven out during the cleaning and ginning. It is certain 
that the large number found in seed when hand-ginned were never 
found in commercially ginned seed. 
Table VI. — Number of pink bollworm larvse found per pound and the estimated number 
per bale in cotton from different pickings. 
Double seed. 
Single seed. 
Weight of sample. 
Number 
double 
seed. 
Number 
larva? 
in 
double 
. seed. 
Esti- 
mated 
number 
of lar- 
vae per 
bale in 
double 
seed. 
Per cent 
of total 
larvae 
in 
double 
seed. 
Number 
single 
seed 
dam- 
aged. 
Number 
larvae 
in 
single 
seed. 
Esti- 
mated 
number 
of lar- 
vae per 
bale in 
single 
seed. 
Per cent 
of total 
larvae in 
single, 
seed. 
Esti- 
mated 
number 
of lar- 
vae per 
bale in 
single 
and 
double 
seed. 
First picking: 
1 pound 
Second picking: 
1 pound 
Third picking: 
1 pound 

43 
189 

39 
161 

58, 500 
241, 500 

56. 5 
28.5 
121 
392 
1,749 
6 
30 
404 
9,000 
45,000 
606,000 
100 
43.5 
71.5 
9,00) 
103,560 
847, 500 
Gough (o), in one of his earlier publications, states that there are 
two generations of the hibernating larvae, the older generation con- 
