Material. 
Avocado: 
7 seeds. . 
6 seeds. . 
10 seeds. 
DO! a6 
Sorghum 
seed. 
eeeee 
eeeere 
A METHOD OF FUMIGATING 
——— — 
Infested with— 
Larvee of Conotrache- 
lus sp. and broad- 
nosed grain weevil, 
all stages. 
4 with all stages of |... 
broad-nosed grain 
weevil; 2 uninfested. 
NICOly hears -.-2 
ats GOMeeclc cases ces Se: 
IBTUCHUSSDs- =se --- -=-- 
_ Bruchus sp. and rice 
weevil (Calandra 
ory2za). 
Rice weevil and ¢ca- 
delle ( Tenebroides 
mauritanicus). 
Bulb mite (Rhizogly- 
phus hyacinthi). 
Kind of eyanid 
and amount 
used. 
Sodium eyanid, | 
2 gms. 
Sodium cyanid, 
4 gms. 
Sodium cyanid, 
2 gms. 
Sodium cyanid, 
4 gms. 
Sodium cyanid, 
4 gm., in des- 
iccator. 
Potassium cy- 
anid, 2 gms. 
Sodium cyanid, 
3 gm., in des- 
iccator. 
Cotton seed.| Adults ofthe red grain | Sedium cyanid, 
beetle (Cathartus ge- 
mellatus). 
13 gms. 
Gleditsia si-! Bruchussp. (adults)..| Sodium cyanid, 
nensis in 
seed pods. 
Phaseolus 
vulgaris. 
Pineapples . 
Tussock 
moth 
(He mero- 
campaleu- 
250 egg 
masses. 
The results given in Table I indicate 
Pseudococcus sp. - ---- 
2 gms. 
Sodium cyanid, 
4 gms. 
Sodium cyanid, 
4 gm., in des- 
iccator. 
Sodium cyanid, 
2 gms. 
Sodium cyanid, 
4 gms. 
of 
SEED. 
Time 
Result. 
expo- 
sure. 
Hrs. 
+ | 1 grain-weevil lar- | 
va alive. 
4 | All stages dead.... 
Out of several hun- 
dred specimens 
1 live adult was 
found. 
ee 
Insects alive 
ee Ne 
ie 
Ali mites dead.... 
Allinsects dead... 
All insects dead, 
both in and out 
of seed pods. 
4} Somelarve 
hatched several 
days after expo- 
sure. 
4 | No hatching. .-.-.-. 
All stages dead...) 
| 
} 
| 
| 
meee! 
TaBLE I.—Summary of experiments in fumigating against insects—Continued. 
Cermination test. 
Not planted. 
3 seeds planted and all 
germinated. 
Not planted. 
Do. 
75.5 per cent germina- 
tion; seed badly in- 
fested. 
71 per cent germina- 
tion; seed badly 
eaten. 
83 per cent germina- 
tion. 
Of four grades fumi- 
gated, the percentage 
of germination was 
as follows: 78.5; 86.5; 
88; 83. 
Germination of fumi- 
gated seed superior 
to that of untreated 
seed. 
Seed thoroughly in- 
fested with insects 
previous to fumigat- 
ing and only 15 per 
cent germinated. 
Bulbs thoroughly in- 
fested and unfit for 
planting. 
Not planted. 
Percentage of germina- 
tion approximately 
the same with both 
fumigated and un- 
treated seed. 
Do. 
Germination of fumi- 
gated seed superior 
to that of untreated 
seed. 
Not planted. 
that the fumigation of seeds 
by the introduction of hydrocyanic acid into an air-tight chamber, 
from which the air has been practically exhausted, is effective, 
provided the exposure is not less than half an hour. 
An exposure 
of one-fourth hour is effective with the apparatus employed in these 
experiments if four or more grams of cyanid are used. 
