CONTENTS 
[ntroduction 7 
Condi! ions favoring or necessary to good results 9 
[solal ion of grove 9 
Concerted action 9 
Absence or elimination of food plants oil mm- than citrus 9 
Season of the year LO 
Meteorological elements 11 
Size of i rees and regularil y of setl ing ' IT 
Equipment .' 14 
Tents 14 
Poles and uprights 20 
M iscellaneous requirements 22 
Chemicals 25 
Degree of puril y required 25 
Handling, and aecessil y for protect ion from moist lire 25 
Proporl ion of water and acid 25 
Procedure 27 
Methods of handling tents 27 
Measuring trees 30 
Method of generating the gas 35 
Work roni ine 3G 
Est i nun ion of time required for fumigation of grove 38 
Methods of computing approximate diihensions and cubic contents 39 
Dosage requirements for the white fly 40 
Experiments with sheet tent . 40 
Experiments with bell or hoop tenl 49 
Miscellaneous experiments and observations 50 
Appearance of Iarvse and pupae of the white fly when destroyed by fumiga- 
tion 50 
Density of the gas at various heights a hove the ground 51 
Effect of himigation on the trees 51 
Sugge.-t ions for the fumigation of small trees 54 
In the grove 54 
In the nnr.-ery 54 
Nursery stock for shipment 54 
Precautions 55 
Expense of fumigation 56 
For equipment 56 
For chemicals 58 
For labor 58 
Economy of treatmenl by fumigation 59 
Losses prevented 59 
( lost of fumigat ion compared wil li spraying 62 
Fumigation versus nat ural control 63 
Appendix 66 
Table of dosage for the citrus white fly 66 
Index nit 
