126 
readily serves to keep the leaves in a thoroly healthy condition. 
and at the same time wets the beds but little."* 
Fumes of sulphur or hydrocyanic acid gas will kill the red 
spider, but the strength required is by far greater than the plants 
will stand. After the cucumber or other crop has been gathered, 
and before infested vines have been removed, it is advisable to 
fumigate them with one of these two substances, using one ounce 
of cyanide of potassium to one hundred cubic feet of space, or 
burning one pound of sulphur to one thousand cubic feet. It is 
hardly necessary to say that these strengths will kill living plants. 
(For full directions for the use of these materials, see pages 156 
and 159.) 
Sulphur is one of the best remedies for the red spider, and 
most of the remedies that have been recommended require sul- 
phur as one of the ingredients. Liberally dusting the plants witli 
sulphur after syringing is effective, or, better, applying a spray 
consisting of one ounce of sulphur to one gallon of water. A little 
soap added to this sulphur solution will increase its efficiency. 
Soap solutions, either whale-oil or a neutral soap such as the 
"Ivory," are of great value in the eradication of the pest, Init the 
addition of sulphur as mentioned above increases their value. 
A lye-sulphur mixture has recently been recommended bv Dr., 
F. H. Chittenden, and is said to be more effective than any of the 
many other materials tested. Directions for pre])aring this spra\' 
are given on page 155. 
Whatever insecticide is used, especially when the infestation 
is severe, should be applied with as great pressure as practicable, 
for the greatest trouble in controlling this mite arises from the diffi- 
culty in penetrating the web which it spins. The stream should 
also be directed to the lower surfaces of the leaves, for it is here 
that the spider is most often found. 
The Eel- worm 
Hetcrodcra radicicola Greefif 
The eel-worm is a common pest in hothouses, particularlv in- 
jurious to the cucumber, and, unfortunately, it is apparently becom- 
Fig. 19. Nematode worm, Hetcrodcra radicicola. among particles of 
soil. Greatly magnified. (Massachusett.s E.xperiment Station.) 
*The Common Red Spider, by F. II. Chittenden. Circ. U. S. Dept. of Agr., 
Bur. of Ent.. No. 104 (Jan. 26, 1909), p. 8. 
