NEMATODE DISEASE OF WHEAT. 
23 
Table III. — Effect of hot-tcater treatment on active larvce of the wheat nematode 
taken from galls. 
Number 
of lots of 
larvae 
of about 
300 each. 
Hot-water treatment. 
Extent 
of obser- 
vation 
(days) 
Larvae living (per cent). 
Experiment. 
Date. 
Temper- 
ature 
(°C). 
Dura- 
tion. 
By lots. 
Average, 
by treat- 
ments. 
1 
2 
No. 9 . 
1 
1 
1 
1 
1 
1 
1 
2 
2 
2 
1 
1 
1 
2 
2 
1 
2 
2 
1 
1 
2 
2 
1 
1 
2 
2 
1 
1 
2 
2 
1 
1 
1 
2 
2 
1 
1 
2 
2 
1 
1 
2 
2 
2 
Mar. 27 
...do 
...do 
...do 
...do 
...do 
...do 
Mar. 26 
Apr. 29 
May 7 
Mar. 27 
...do 
Apr. 15 
Apr. 29 
May 7 
Apr. 15 
Apr. 29 
May 7 
Apr. 15 
Mar. 27 
Apr. 30 
48 
48 
• 48 
49 
49 
49 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
50 
51 
51 
Minutes. 
3 
5 
6 
3 
6 
10 
3 
5 
5 
5 
6 
10 
10 
10 
10 
15 
15 
15 
20 
3 
3 
3 
6 
6 
6 
6 
10 
10 
10 
10 
15 
3 
3 
3 
3 
6 
6 
6 
6 
10 
10 
10" 
10 
Days. 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
4 
6 
4 
4 
6 
4 
4 
6 
4 
4 
4 
4 
6 
4 
4 
4 
6 
4 
4 
6 
4 
6 
4 
4 
4 
6 
4 
4 
4 
6 
4 
4 
1 | 
85 
90 
50 
90 
50 
20 
75 
50 
.6 
3 
15 
5 







20 
2 
2 
1 

2 








10 
1 


.16 

.0 



95 
95 
95 
85 
No. 10 
90 
No. 11 
50 
No. 6... 
90 
No. 7 
50 
No. 8 .. 
20 ' 
No. 3 . . 
75 
No. 1-2 
60 
4 
1.5 
1 
No. 27-28 
\ 19.7 
No. 45-46 
I 
No. 4 
15 
No. 5 
1 
No. 18 
, 
No. 29-30 


No. 47-48 
No. 19 
1 
No. 31-32 . . 


o 
No. 49-50 
[ 
No. 20 

No. 12 
1 5.8 
No. 33-34 
4 
1 
No. 51-52 
S May 7 51 
Mar. 27 51 
Apr. 15 51 
Apr. 30 51 
Mav 7 51 
Mar. 27 
( 
No. 13 
1 * 7 
No. 3.5-36 
1 

No. 53-54 
No. 14 
1 
No. 22 
Apr. 15 
Apr. 30 
May 7 
Apr. 15 
Mar. 27 
Apr. 15 
Apr. 30 
May 7 
Mar. 27 
Apr. 15 
Apr. 30 
May 7 
Mar. 27 
Apr. 15 
Apr. 30 
May 7 
(Mar. 27 
^Apr. 29 
(.May 7 
51 
51 
51 
51 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
52 
No. 37-38 


° 
No. 55-56 
No. 23 

No. 15 
| 
No. 24 
l 2.2 
No. 39-40 
1 
.6 
J 
No. 16 
1 
No. 25 
No. 41-42 
2 

f ' 3 
No. 59-60 
J 
1 
No. 26 
No. 43-44 


95 
95 
95 

No. 61-62 
J 
I 95 
1 
1 Room temperature. 
It is to be noted that neither the submersions at 48° nor 49° C. 
were of sufficient duration to kill all the larvae, even though the 
number remaining alive was somewhat below that of the untreated 
lots held as a check. Treatments with water at 50° to 52° C. gave 
uniform results ; that is, the percentage of larvae surviving varied 
directly with the length of immersion. For example, at 50° C., 19.7, 
15, and 0.8 per cent survived after exposures of 5, 6, and 10 minutes, 
respectively, while none lived where the exposure lasted for 15 min- 
utes. Comparable results were obtained at higher temperatures, 
with all. larvae succumbing at 51° and 52° C. in 10 minutes. It is 
interesting to note that the minimum length of time required to kill 
