CONTEXTS. 



Page. 



Historical 1 



Recent renewal of interest in fumigation in California 2 



Extent to which fumigation is practiced in California 3 



The various systems of fumigation 4 



By contract 4 



By associations 5 



By counties -• 5 



By private individuals 5 



Extent and character of citrus orchards 6 



Insect enemies of citrus fruits 7 



The purple scale (Lepidosaphes beckii Newm. 8 



The black scale (Saissetia olex Bern. ) 8 



The red scale ( Chrysomphalus aurantii Mask.) 9 



The yellow scale ( Chrysomphalus citrinus Coq. ) 10 



The mealy bug (Pseudococcus citri Ris>o) 10 



Apparatus 10 



Tents 10 



Sheet tents 10 



Sizes 11 



Materials used 11 



New tenting material 11 



Experiments with new tent material 12 



What cloth to use 12 



Construction 13 



Amount of cloth required for different sized tents 14 



Size to purchase 15 



Ring attachments and reenforcements 15 



Bell tents 16 



Gas-proofing 16 



Mildew-proofing 18 



Marking 19 



Poles and derricks 20 



The McFadden machine 21 



Supply cart and supply wagon 22 



Generating vessels 24 



General procedure 24 



Calculating the dosage 27 



Securing the measurements around and over 28 



The Morrill method 29 



The old method of procedure 30 



An improved system of fumigation 32 



Leakage of gas 33 



Dosage schedule 34 



Procedure 37 



Advantages under this system 37 



Experience with this system 38 



VII 



