22 
BULLETIN 842, U. S. DEPARTMENT OF AGRICULTURE. 
to 12 minutes in water at a temperature of 5^° to 56° C. If the 
statements of these investigators, however, were supported by ex- 
perimental data these were not presented, and furthermore, they 
failed to mention the important point as to whether they were treat- 
ing dry galls or those that previously had been soaked in water. 
Table II. — Effect of Jiot-icater treatment on larva? of the wheat nematode in- 
closed in dry galls. 
Hot-water treatment. 
. Larvae active (per cent). 
Number 
Lot. 
of galls, 
each con- 
taining an 
average 
Temper- 
Extent of 
observa- 
tion after 
In each gall at last 
examination. 
Avers 
ge — 
of more 
than 1,500 
Date, 
1918. 
ature 
(°C). 
Duration. 
treatment 
(days). 
In 
In 
larva?. 
1 
2 
3 
4 ! 5 
6 
each 
lot. 
each 
treat- 
ment. 
Minutes. 
No. 1 
6 
Mar. 13 
50 
10 
2 



15 
5 

3.3 
3.3 
No. S 
5 
June 5 
50 
15 
4 
35 
35 
90 
30 
90 
56 
56 
No. 2 
6 
Mar. 13 
50 
. 20 
2 

75 

2 

"6" 
S. 5 
J36.7 
Xo.9 
5 
June 5 
50 
20 
4 
40 
10 
90 
75 
80 
65 
No.2« 
5 
June 17 
50 
30 
3 
60 
. 5 
50 
25 
10 
29 
29 
Xo. 2"i 
5 ...do 
50 
35 
3 
10 
20 

40 

14 
14 
No. 26 
5 ...do 
50 
10 
3 

15 
s 

5 
5.6 
5.6 
Xo. 27 
5 ...do 
50 
45 
3 

.06 
15 
20 

7.1 
7.1 
Xo. 10 
5 
June 5 
52 
10 
4 
35 
80 
75 
45 
90 
65 
65 
Xo. 11 
5 
...do..... 
52 
15 
4 
10 
65 

10 

17 
17 
Xo. 12 
5 
...do..... 
52 
20 
4 
90 
20 

70 

36 
36 
Xo. 2-? 
5 
June 17 
52 
25 
4 
1 
20 
15 
55 
40 
26.2 
26. 2 
Xo. 13 
5 
June 5 
51 
10 
4 


60 

60 
24 
24 
Xo. 5 
6 
Mar. 13 
51 
15 
2 





} 6.5 
Xo. li 
5 
June 5 
51 
15 
4 


35 
10 i 20 
13 
Xo. 15 
5 
...do 
51 
20 
4 
30 



6 
6 
No. 16 
5 
...do 
56 
5 
4 
; 
90 
45 
60 80 
55 
55 
Xo. 17 
5 
...do 
56 
10 
4 

75 
40 


21 
21 
No.l? 
5 
...do 
56 
15 
4 






}•* 
No. 23 
5 
June 17 
56 
15 
3 



.2 

.2 
No. 3 
6 
Mar. 13 
5S 
5 
2 

5 

75 

~3o' 
IS. 6 
J29.S 
}2S.5 
Xo. 1 
5 
June 5 
5S 
5 
4 
50 

65 
90 

41 
Xo. 4 
6 
Mar. 13 
5S 
10 
2 

80 
.06 


"6' 
16 
Xo.2> 
5 
June 5 
58 
10 
4 
50 

65 
90 

41 
Xo. 6 
6 
Mar. 13 
60 
5 
2 
50 75 
2 
3 
80 
75 
47.5 
}3S. 7 
No.21 
5 
June 5 
60 
5 
4 
70 
80 


30 
Xo. 22 
5 
...do 
60 
10 
Days. 
3 
4 






Check 
6 
Mar. 13 
C 1 ) 
3 
95 95 
95 
95 
95 
95 
J95 
1 
Do 
5 
June 5 
0) 
4 
4 
95 95 
95 
95 
95 
95 
Room temperature. 
LARViE OUTSIDE OF THE GALLS. 
Active larva? liberated from galls were exposed to hot water in 
the following manner in order to ascertain their response to high 
temperatures. By means of a glass dropper about 300 nematode 
larva? were transferred to diminutive bags of silk and then pin ceil 
in a large receptacle of water of the desired temperature. After a 
specified time the bags were removed, the contents of each immedi- 
ately emptied into distilled water in a Syracuse watch glass, and 
the larva? examined microscopically on each of several days follow- 
ing the treatment. The highest percentage of nematodes found living 
at any one observation was recorded and is presented in Table III. 
