216 
GARDENING IN THE SOUTHWEST 
Chewing 
Insects 
Sucking 
Insects 
When to 
Spray 
Scaly 
Insects 
plant after reaching some part of it. To combat this, the entire sur¬ 
face of the leaves and stems must be covered with some material 
that destroys the disease. Sulphur , in some form, is considered the 
most effective remedy, in solution or as a dusting powder. Massey 
Dust , which can be prepared at home, is extensively used. Bordeaux 
Mixture is often advised, but it has the objectionable quality of 
discoloring the foliage. 
The chewing insects can only be killed by covering the plants 
with poison, for it is swallowed as they eat the foliage. Caterpillars 
and bugs are the greatest offenders of this class. The mixtures that 
contain arsenate of lead and Paris Green are most commonly used. 
The sucking insects cannot be reached by stomach poisons, yet 
there are a number of materials that kill by direct contact. Nico¬ 
tine (tobacco) is the one most generally used. When it covers the 
soft-bodied insects, like plant lice (Aphis), it is absorbed and 
causes death almost immediately. The simplest method is to use 
Black Leaf 40, diluted, or combined with other materials. 
One cannot use this until the pests appear, yet an early applica¬ 
tion after they have been discovered gains control of the situation. 
When the bodies of the insects are not soft and the Nicotine 
cannot penetrate, then an oil spray, or soap and oil, must be used to 
completely smother them, for they breathe through pores. Direct 
contact with each insect is required to entirely destroy them, 
therefore, it is safer to spray once a week for several weeks. 
