14 BULLETIN 480, U. S. DEPARTMENT OF AGRICULTURE. 



in the spark-plug holes to prevent moisture from entering the cylin- 

 ders. The panels should be taken from both sides of the engine and 

 all oil removed from crank case, after which the crank shaft and 

 connecting rods should be coated with heavy grease. A few drops 

 of light oil should be worked into all metal parts of the magneto 

 bearing to prevent rusting. 



SUMMARY. 



The subject of spraying, either solid-stream or mist spray, should 

 be given very careful consideration, as the importance of securing 

 good results is imperative. If they are accomplished, much more 

 interest and cooperation may be expected in the problem of con- 

 trolling leaf-eating insects. It often happens that those responsible 

 for the results do not give sufficient attention to important details 

 until it is too late in the season to secure the best results. One should 

 familiarize himself with every phase of spraying, so that he may 

 be able to cope with all conditions. While there are still those at the 

 present time who do not feel that solid-stream spraying with arsenate 

 of lead can be as effective as that done with smaller machines and mist 

 nozzles, all will concede that much good work has been accomplished 

 in the gipsy-moth area in New England with solid-stream spraying. 

 While the solid-stream method is confined almost entirely to shade- 

 tree and forest spraying it has been used successfully in orchards 

 (PI. XVI). Solid-stream work is not necessarily confined to the 

 highest-power machines, as good results may be obtained on a small 

 scale with medium-power machines capable of delivering a solid 

 stream of smaller size, and which at the same time may be easily 

 converted to mist-spray work. This also applies to the larger 

 machines. 



The problem of fighting the gipsy moth and the brown-tail moth is 

 of such magnitude and general economic importance that it would 

 be impossible to do the necessary spraying in the infested area with 

 mist spray and small machines.. During part of many seasons the 

 weather is not suitable for spraying, and when conditions are right 

 a large amount of spraying must be accomplished in a short time. 

 The work of several boring insects which have riddled our shade 

 trees in the past few 3'ears has also made climbing of them much 

 more hazardous, but this must be done if the mist spray is used. If 

 climbing is resorted to, the expense is prohibitive, especially in wooded 

 areas. 



Many times the question is asked, "Why pursue other methods 

 of fighting the gipsy moth and the brown-tail moth; why not confine 

 it entirely to spraying?" There are several reasons; the nature 

 and severity of the infestation must be taken into consideration, 

 and the proximity and danger of spread to noninfested regions. 

 If extermination is to be expected it would not be wise to confine all 



