93 



bolted together, if such upport is required, and the cavity filled with 

 cement. It is best to have any important work of this kind done by an 

 expert in tree surgery, if such services are available. 



Clean Cu ture. — All dying and dead branches and trees shoidd he 

 removed and burned. Many insects and rot-causing fungi breed in such 

 material and emerge therefrom to attack weakened or even healthy trees 

 or branches. // is of the utmost importance to cut out or collect all such 

 material promptly and burn it so as to destroy the pests which it contains. 

 Each winter remove all dying and dead trees and parts and burn them 

 before spring. Make it a rule to remove and burn all dying w^ood as soon 

 as it is detected. 



General Methods of Control. 



The chief injurious insects may be grouped as defoliating insects 

 sucking insects, and borers in the bark and wood. 



Most leaf-eating insects may be controlled readily enough by the 

 ordinary poison sprays of Paris green or lead arsenate. Very strong 

 mixtures are at times required, and it is sometimes advisable to employ 

 a spray of very strong contact insecticide as a more rap d control for hordes 

 of caterpillars. 



Sucking insects are controlled by spraying with strong contact insec- 

 ticides such as kerosene emulsion, fish-oil soap, and good tobacco extracts. 



Spraying. — The spraying of shade trees requires the insecticies and, in 

 general, the methods employed in the spraying of orchard trees; except that 

 we have to reach greater heights, and in such cases need a more powerful 

 apparatus. For spraying the lower foliage the ordinary nozzles and 

 equipment are used; but to reach the top of the higher trees it is necessary 

 to employ a solid stream and a powerful sprayer of large capacity. A 

 few of the power spray-pumps sold for orchard work will maintain a solid 

 stream for 60 feet up from the nozzle; other pumps, excellent for general 

 work in the orchard, have a small pump capacity and are unable to main- 

 tain a solid stream above 40 feet. By using a good "solid stream" nozzle, 

 such as the Worthley, and elevating the nozzle on a platform or ladder, 

 the average orchard power sprayer can be made fairly effective for shade- 

 tree work. For towns and cities where large numbers of tall trees are to 

 be sprayed a special power sprayer for shade tree purposes should be ob- 

 tained. Such pumps are now available, capable of maintaining a solid 

 stream from 80 to 100 feet up from the nozzle. 



