2 
rather than to permit the presence of such grove to interfere with 
his results. 
Full directions concerning equipment, chemicals, and methods of 
procedure in fumigating for the citrus white fly have been published 
in a bulletin of this Bureau.“ This bulletin is based upon results 
obtained in January and February, 1907. Extensive field experi- 
ments have been conducted during the last two seasons and the 
additional results obtained will be embodied in a supplementary 
report now in preparation by the authors of this circular. It is 
hoped that before the beginning of the next fumigating season, 
extending from December 1 to March 1, a publication in the Farmers’ 
Bulletin series of this Department will be available. This bulletin 
will contain only such advice and directions as are of practical 
importance in fumigation work against the white fly, omitting the 
details of experiments published elsewhere as the necessary basis 
for establishing practical conclusions. The present circular aims to 
call attention to the desirability and in most cases necessity for 
early preparations where fumigation work is planned for the coming 
winter season; also to give full directions for such preparations. 
EQUIPMENT. 
TENTS. 
- Orders for tents should be placed as soon as possible after it is 
decided to fumigate a grove. Tent makers do not always have on 
hand a sufficient quantity of desirable grades of canvas to fill large 
orders. Delays in filling the order may necessitate shipment by 
express, at a cost several times the expense of shipment by freight. 
The first step is the determining of the sizes of tents required. It 
is a more common mistake to underestimate the size of a tent required 
than to overestimate it. Some allowance should be made for the 
growth of trees, in consideration of the future use of the tents. If 
the trees are nearly uniform in size, the largest trees should be selected 
for measuring. A tape measure attached to a reel is used in meas- 
uring trees to determine the size of tent required. Standing a few 
feet from the outside branches of the tree to be measured, enough 
of the tape is unreeled to extend over the top of the tree and about 
half way to the ground on the other side, the free end of the tape is 
held in one hand and the reel is thrown over the center of the tree 
and unreels the tape by its own weight until it reaches the ground. 
Two or three attempts may be necessary in order to have the tape 
pass over the center of the tree. It should be borne in mind that the 
weight of the tent will reduce the extreme height of the tree and that 
«Bul. 76, Bur. Ent., U. S. Dept. Agr., Fumigation for the Citrus White Fly as 
adapted to Florida conditions. By A. W. Morrill. 
(Cir. 111] 
