70 FUMIGATION FOE THE CITRUS WHITE FLY. 
V&ge. 
Fumigation against citrus insects, history 7-8 
white fly, absence or elimination of food plants other than 
citrus favorable 9-10 
appearance of dead larvae and pupa? 50-51 
chemicals, cost 58 
handling, and protection from mois- 
ture 25 
proportion of water and acid 25-27 
purity required 25 
concerted action favorable 9 
conditions favorable or necessary to good results.. 9-14 
cost compared with spraying 02-03 
density of gas at various heights above ground. . 51 
dosage requirements with bell or hoop tent 49-50 
sheet tent 40-49 
economy of treatment 59-63 
effect on trees and fruit 51-54 
equipment 14-24 
expense 50 
history 7-8 
isolation of grove favorable 9 
losses prevented thereby 59-00 
measuring trees 30-35 
meteorological elements favorable 11-13 
method of generating gas. 35-30 
handling bell tents 29 
sheet tents 27-29 
methods of computing cubic contents of tented 
tree 39-40 
dimensions of tented trees 39-40 
miscellaneous experiments and observations 50-54 
requirements 22 24 
nursery stock for shipment 54-55 
poles for handling tents 20-21 
precautions 55-50 
procedure: 27 ' \S 
proportion of water and acid 25 27 
season of year favorable , 10-11 
table of dosage 66-68 
tents, care L9 20 
construction 15-19 
mildew-proofing, oiling, and painting 19-20 
shrinkage 17-18 
st vies 14-15 
time required 38-39 
trees, regularity of setting favorable 14 
size favorable 14 
small, in the grove 54 
nursery 54 
uprights for handling tents 21 
versus natural control 03-05 
work routine : '30-3S 
Fungous diseases in control of white flv 04-05 
