EXPERIMENTS FOR CONTROL. 29 
being with the hands. A section about 3 inches long should be 
coated with the tanglefoot, care being taken that no parts are missed 
and that no leaves are left to form a bridge across it. Although the 
tanglefoot is apparently very disagreeable material to apply, it is 
easily washed off the hands with a little kerosene or even with soap 
and hot water. 
METHODS OF APPLYING SPRAYS. 
No spraying for the red spider should be attempted unless the 
proper appliances and machinery are at hand. Hand pumps which 
will maintain 150 pounds pressure can be used, but power outfits 
are preferable. Traction and compressed-air sprayers which will 
maintain the proper pressure are light, convenient, and readily hauled 
through the hopyards, but unless the required pressure is maintained 
they will not give satisfactory results in spraying. The outfits used 
in the experimental work at Sacramento were composed of a gaso- 
line engine, a spray pump, and a 50-gallon barrel mounted upon a 
light three-wheeled truck. These outfits did effective work, but 
carried so little spray material that they required refilling entirely too 
often. A large orchard power outfit (PL VI, fig. 2) equipped with 
two 150-foot lines of hose was operated around the edges of some of 
the yards with good results. The driver assisted the rodmen in get- 
ting the hose in and out of the rows and a wide strip around the yards 
was treated. In cases where the infestation appears on one side of a 
field such machines can be readily employed. 
The mites are almost entirely found on the underside of the leaves, 
and in order to wash them thoroughly the spray must be directed 
from below. When angle nozzles are not available the spray rod may 
be bent so that the spray may be readily directed to the underside of 
the leaves. If one or the other of these methods is not employed the 
material will not be satisfactorily applied. 
In order to penetrate all of the webs and reach all of the mites it is 
necessary to use a nozzle that will throw a washing rather than a 
mist spray. The Bordeaux or " stopcock" type is usually too coarse 
and wastes material, so that a nozzle should be chosen somewhere 
between that and the Vermorel type. Some of the recent makes can 
be regulated by the alteration of the size of the opening in the disk 
so that any degree of spray can be obtained. Such nozzles are very 
well adapted to the red-spider work. 
In controlling the red spider in the hop fields it is necessary that a 
large territory be covered in a short time and that the material be 
applied very thoroughly. To do this several outfits are necessary 
and these must be in good working condition. Disabled machinery 
not only increases the expense of spraying but reduces the chance of 
controlling the mites. 
