48 
BULLETIN 1374, U. S. DEPARTMENT OF AGRICULTURE 
Table 40. — Thermal death point of unprotected pink bollworm larvse exposed in 
swinging cage in Freas oven 
Number 
Cage 
Time of 
Cage 
1 
of 
temper- 
temper- 
Mortal- 
larvae 
ature 
expos- 
ature 
ity 
exposed 
at start 
ure 
at end 
°F. 
Minutes 
°F 
Per cent 
10 
88 
13M 
135 
60 
8 
80 
uy 2 
135 
62.5 
10 
85 
VA 
135 
50 
10 
77 
15M 
140 
100 
10 
81 
uy 2 
140 
100 
10 
80 
mi 
140 
100 
10 
82 
10 
140 
100 
10 
82 
9M 
140 
100 
10 
83 
9 
140 
100 
10 
84 
8 
140 
100 
5 
81 
m 
140 
100 
10 
80 
m 
140 
100 
10 
83 
7 
140 
100 
10 
82 
7 
140 
100 
10 
86 
6M 
140 
100 
10 
83 
7 
140 
100 
10 
84 
6H 
140 
100 
10 
82 
6V 2 
141 
100 
8 
82 
19 
145 
100 
10 
92 
10M 
145 
100 
10 
87 
7H 
145 
100 
10 
85 
6M 
145 
100 
10 
84 
6 
145 
100 
10 
79 
18K 
150 
100 
10 
84 
IVi 
150 
100 
10 
84 
5Vz 
150 
100 
Table 41. — Thermal death point of unprotected pink bollworm larvae exposed in 
blotter tray in Freas oven 
Number 
of larvae 
exposed 
1 ■ 
Tern-" 
perature 
in tray 
at start 
Time of 
exposure 
Tem- 
perature 
in tray 
at end 
Mortality 
O J? 
Minutes 
o F 
Per cent 
8 
81 
16H 
135 
87.5 
.7 - 
91 
13K 
135 
100 
9 
101 
8V 2 
136 
100 
8 
81 
18M 
140 
100 
10 
90 
12M 
140 
100 
7 
100 
H 3 4 
140 
100 
8 
99 
1014 
100 
100 
8 
100 
8V 2 
140 
100 
11 
101 
8V 2 
140 
100 
10 
102 
8H 
140 
100 
8 
102 
8H 
140 
100 
9 
100 
8 
140- 
100 
9 
90 
\M 
142 
100 
10 
99 
9V 2 
142 
100 
The air in the oven during all these experiments was dry. The 
thermal death point as indicated by these tests is 140° F., or between 
135 and .140° for the conditions under which these tests were made. 
The results agree closely with those of Willcocks. 15 
COMMERCIAL DISINFECTING MACHINES 
From the writer's experiments it appeared that the heating of cot- 
tonseed to a temperature sufficient to kill the pink bollworms con- 
tained therein and at the same time not to injure the seed, would 
be comparatively simple. The main difficulty in perfecting a com- 
15 F. C. Willcocks. Op. cit. 
