74 BUREAU OF PLAXT QUARANTINE 
[July-Sept. 
Fumigation should be carried out when the air is at a temperature of 70° to 
80° F., and under no circumstances is fumigation at an air temperature below 60° 
to be considered as complying with the fumigation requirement. Night fumigation 
should not be undertaken because of the low temperatures. 
The bulbs are to be dry and free from soil when placed in the fumigator and 
are to be so spread out that good circulation is possible. All rotted bulbs are to be 
sorted out before fumigation. The bulbs are to be placed in trays with open slat 
or wire bottoms and are to be not more than two layers deep in each tray. The 
trays are to be well separated so as not to occupy more than 75 per cent of the 
capacity of the chamber. 
In most sections of the United States atmospheric moisture is sufficient to 
provide for the release of the gas. In very dry areas in the Pacific coast section, 
a slight humidity may be provided in the fumigation chamber by wetting and 
wringing out a piece of burlap, placing it on the floor of the fumigation chamber, 
and covering it with dry newspapers. Under no circumstances must any moist 
paper or cloth or other moist object come in contact with the calcium cyanide 
as that changes the chemical nature of the gas released and makes it relatively 
ineffective. 
Whenever known greater-bulb-fly-infested material is available, some infested 
bulbs are to bs included in each charge. When it is found that fly larvae are 
surviving in this material, such remedial steps as are necessan^ with respect to 
the construction of the fumigator, the securing of fresh cyanide, etc., are to be 
taken, and the entire load is to be refumigated. In determining survival, inspec- 
tion of the known infested material should preferably be repeated two days or 
more after fumigation to detect any revival of fly larvae. 
Records are to be kept of the exact time and temperature at the beginning and 
end of each fumigation and of the exact lots and varieties of bulbs and the number 
of each variety. Fumigation is to be supervised by the inspector. In cases of 
insufficient inspection personnel, the inspector may authorize the grower to 
proceed with fumigation for limited periods in the inspector's absence, making 
the grower himself or one of his competent employees responsible. In such cases 
the records are to be kept by the grower or employee in charge. Except where 
a grower has been definitely authorized by an inspector to proceed with the 
treatment, fumigation carried out in the absence of the inspector is not considered 
as fulfilling the requirements for the issuance of Federal permits and must be 
repeated in the presence of an inspector before such permits are issued. 
FUMIGATION WITH SODIUM CYANIDE AND SULPHURIC ACID 
The pot method of fumigation may be substituted for the procedure described 
if desired. Use 7 ounces of sodium cyanide (50 per cent cyanogen), 10}£ ounces 
of sulphuric acid (66° B.), and 14 ounces of water for each 100 cubic feet of space. 
First dilute the acid, pouring it slowly into the water (not the water into the 
acid) . 
The construction of the fumigation chamber, the arrangement of the bulbs, 
the limitations on air temperature, and the general plan of operation are the 
same as outlined in the previous section, but special apparatus must be used for 
getting the cyanide into the dilute acid after the door of the fumigation chamber 
is closed. The cyanide is to be suspended over the acid and released by a cord 
or lever after the closing of the door. 
Fumigation by this process should not be attempted except under the super- 
vision of an experienced inspector, owing to its danger to the operator and others. 
HOT-WATER TREATMENT FOR NARCISSUS BULB FLIES 
Growers not equipped for fumigation, or who prefer hot-water treatment to 
fumigation, are authorized to use this treatment where bulb flies alone occur on 
the premises. Bulb flies are more susceptible to hot water than are eelworms and 
the time of treatment is less. The following method is authorized as a condition 
for the issuance of permits for bulb-fly-infested bulbs in which eelworm infestation 
is not involved: 
Treatment with hot water at from 110° to 111.5° F., for a period of one hour 
computed from the time the water regains the loss of temperature occasioned 
when the bulbs are submerged. Prolonging the treatment to three hours to kill 
undiscovered eelworms is recommened but wdll not be required in the absence 
of knowm or suspected eehvorm infestation. 
The equipment needed is described in connection with the discussion of treat- 
ment for eelworms. Provision should be made, as in the case of eelworm treat- 
ments, to prevent the dissemination of basal rot or other bulb diseases. 
