PROTECTION FROM THE LOCUST BORER. 11 
was planted the beetles present either remained in about the same 
numbers or increased enormously, according as the condition of the 
trees retarded or favored their increase. In no new locality where 
plantations were put out would there be enough beetles present to 
infest all the trees. They only attack all the trees as they become 
sufficiently numerous. 
CONTROL. 
A METHOD OF HANDLING SEVERELY DAMAGED PLANTATIONS. 
Many locust plantations have been abandoned and all hope of ever 
realizing any commercial product given up because of the severe 
devastation produced by the borers. Such tracts look hopeless with 
the greater percentage of the trees broken off or killed, but it is 
believed that they can be reclaimed after several seasons' care by 
virtue of the sprouting ability of this tree. 
It is recommended that all such plantations be gone over and the 
broken-down and infested trees removed and burned during the 
winter. Unless otherwise desired it would be necessary to cut out 
only the living infested trees, because no beetles will breed in the 
dead ones. Especial attention should be given to the seriously dam- 
aged or so-called brood trees. If the cutting out of the infested 
trees can be done early in November it is not necessary to destroy or 
burn the wood. The larvae require living wood for their early 
development and will not mature in dead material. This not only 
will reduce the numbers of the insects, but before the sprouts become 
large enough to be attacked a sufficiently dense stand will have been 
developed to provide natural protection, as illustrated in Plate III, 
figure 1. 
TREATMENT OF SHADE TREES. 
The locust is widely planted for ornamental and shade purposes. 
It is very desirable for such planting, because of its ability to suc- 
ceed well in a variety of soils and situations and its rapid growth and 
good form of crown in the open. We often hear complaints of serious 
injury by the borer to locust shade trees; this is because such trees 
are usually grown in isolated situations most favorable for attack. 
It has been found that the young borers can be killed readily by 
the use of an arsenical spray, applied to the bark when the new 
growth begins to open at the tips of the twigs in the spring. It is 
necessary to apply this mixture so thoroughly as to cover all parts of 
the trunk and reach every spot where a larva is working. 1 
A thorough application will probably be necessary only every two 
years unless there are badly infested trees near by which are not 
treated and form centers of reinfestation. As a rule, spraying will 
1 The presence of a young borer can be determined by the oozing of sap and boring dust 
from a small bole tbrougb the bark. This bole is enlarged as the larva grows. 
