PEOTECTIOX FROM THE LOCUST BOEER. 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 connnercial 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 Idlled, but it is 

 believed that thej^ 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 ISTovember it is not necessary to destroy or 

 bum the wood. The larvag 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 trimk and reach every spot where a larva is working.^ 



A thorough application will probabl}'- 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 



^ The presence of a young borer can be determined by the oozing of sap and boring dust 

 from a small hole through the bark. This hole is enlarged as the larva grows. 



