20 FUMIGATION FOR THE CITRUS WHITE FLY. 
now raised from the water and alter dripping ceases it is spread out to dry. The tank 
lb idled again and the tannin is added until the color is a reddish brown, and then 
another tent may be dipped. 
In Florida fumigating tents become thoroughly wet nearly every 
night they are in use, but even when untreated will not deteriorate 
to any great extent (lining two or three months' use if thoroughly 
diied each day, and more especially before being finally rolled up lor 
storage during the seasons when not in use. Tents are conveniently 
dried each day by simply leaving them on the last tree covered until 
dried by the sun. The edges of the tent should be straightened out as 
soon after sunrise as possible, and folds in the tent should be arranged 
from time to time to facilitate drying. Such work, of course, should 
not ordinarily be considered as part of the work of the fumigating crew, 
but can be readily attended to by some laborer employed at t he grove. 
It is considered by some fumigators that when tents are treated with 
oil it is unsafe to leave the trees covered during bright sunlight, but 
untreated tents can be safely dried in this manner. Drying is prob- 
ably hastened by pulling the tents partly off so as to make an open 
space on one side to give circulation of air. Frequently it is a good 
practice to pull a tent wholly or partially over two trees in order to 
facilitate drying. When tents are dry, to prevent wetting by rain 
and subsequent trouble in drying, they should be rolled tip as com- 
pactly as possible and arranged to shed water as well as practical >le, 
or they may be covered with waterproofed ducking or stored for the 
time being in a dry place. 
Tents must be kept in repair during the fumigating season and 
examined frequently during the daytime for holes which need patch- 
ing. If tents are always pulled lengthwise of the strips of the cloth, 
there is little danger of tearing, except when there is much dead wood 
on the trees. One of the tents used by the agents of the Bureau of 
Entomology during the winter of 1906-1907 was used to cover 
upward of 100 trees without any injury of this kind. 
POLES AND UPRIGHTS. 
Poles and uprights are used, as shown in the illustrations (Pis. II, 
III), for raising the front edge of the fumigating tents when covering 
a tree or pulling the tent from one tree to the next in the row. The 
simple poles are as a rule used for tents not exceeding 48 feet in 
diameter, and usually vary from 12 to 20 feet in length, according to 
the height of the trees to be covered. In California straight-grained 
Oregon pine 2 inches in diameter is generally preferred for poles not 
exceeding 18 feet in length; for poles longer than IS feet the diameter 
should he 2\ inches. In the Gulf regions it is recommended that 
seasoned cypress poles he used, as these are much lighter than the 
available pine. Although only a single pair need he \\>vi\ with an 
