14 
FUMIGATION INVESTIGATIONS IN CALIFORNIA. 
Mealy bugs occur in various parts of the southern end of the State. 
Their appearance is usually spasmodic and in restricted areas. These 
insects are at present more serious than elsewhere in Ventura County, 
where they occur in great numbers. 
The citrus red spider is general in distribution, whereas the silver 
mite is restricted to the region about the city of San Diego. 
INJURY RESULTING TO SCALE-INFESTED TREES. 
In scale insects the mouth is an elongated beak or tube. This 
tube is inserted into the bark or covering of the host plant when the 
insect is feeding, 
and is used to draw 
up the plant juices, 
which are the scale- 
insect's only food. 
When great num- 
bers of these insects 
draw sap from the 
tree, even though 
they are very mi- 
nute, the tree's 
vitality is greatly 
reduced. This ef- 
fect is very marked 
in the attack- of 
the red and purple 
scales. Both of 
these species cause 
much destruction, 
yet the writer is of 
the opinion that the 
red scale will de- 
stroy a citrus tree 
in less time than 
will the purple 
Fig. 6.— Orange tree almost destroyed by red scale. (Original.) qpqIp oil nthpr far- 
tors being equal. Trees have been noticed from two to three years 
after planting which had been killed by the red scale. Large 
orchard trees are frequently destroyed by the pest (fig. 6), while it 
is a very common sight in regions of severe infestation to see large 
branches killed back to the trunk. Although no trees have ever 
come to the writer's attention which were completely killed by the 
purple scale, severe infestations result in the destruction of many 
branches (fig. 7), and cause such a drain on the tree that the produc- 
tion of fruit is greatly decreased. Moreover, the purple scale spread- 
