g FARMERS’ BULLETIN 735. 
and the manner of dispersion of the pest lead to the following cul- 
tural recommendations. 
WEED DESTRUCTION. 
Many weeds and plants serve as sources of dispersion. By destroy- 
ing, during the winter and early spring, pokeweed, Jerusalem oak, 
jimson weed, wild blackberry, wild geranium, and other weeds in 
and around cotton fields, the greatest step toward red-spider control 
will have been taken. This plan has been tested in several instances 
and has given complete immunity the following season. 
CONTROL ON DOORYARD PLANTS, 
A few kinds of cultivated plants, especially violets, remain green 
through the winter and are well adapted to serve as winter hosts of 
od 
Fic. 7.—Portable barrel pump for application of herbicide to weed borders. 
the red spider. Many cases of cotton infestation can be traced to 
near-by dooryards. The beds of violets and other plants should be 
thoroughly sprayed as soon as they show signs of infestation. The 
most satisfactory solution, where violets are concerned, consists in 
their removal or complete destruction. 
HERBICIDES. 
Certain chemical sprays can be applied to weed and plant borders, 
which kill them rather quickly. Of these, sodium arsenate, used at 
the rate of 1 pound to 20 gallons of water, is the most satisfactory. 
The ease and speed of destruction that accompany the use of such a 
remedy justify urging its use as a substitute for the old-fashioned 
