INSECTICIDES, PREVENTIVES, AND MACHINERY. 447 



in the method of application. As a rule, lime may be said to be 

 effective in proportion as it is caustic, and it is then useful against 

 soft-bodied insects. The best way to prepare it is to add just 

 water enough to stone or shell lime to dry-slake thoroughly, then 

 sift and apply the powder as soon as possible. This is more 

 caustic than air-slaked lime, and wall burn a hole through the 

 soft body of most larvae. I have seen it applied on the slugs of 

 the potato-beetle in the morning while they were a little moist, 

 resulting before noon in their complete destruction. So it may 

 be applied to cabbages, and will in the same way destroy the 

 larvae of the cabbage-butterfly. Lime is one of the best mate- 

 rials for use on the larvae of the asparagus-beetle, and is also 

 effective against the slimy or moist saw-fly larvae, including the 

 " currant- worm." To obtain the best effects the lime should 

 be dry and caustic, while the insects upon which it is appHed 

 should be damp or slimy. Wherever a particle of lime sticks 

 it will burn a hole into the insect. Few insects care to feed 

 upon Umed vegetation, and many will not even rest upon a sur- 

 face covered by it ; therefore, lime may be sometimes used as 

 a repellent. Even the rose-chafer, when only moderately abun- 

 dant, will generally avoid lime-dusted foliage. Whitewashing 

 the trunks of trees will prevent the fixing of scale insects upon 

 them, and will discourage borers from laying eggs on or boring 

 into them. A free use of lime in every direction on the farm 

 is advised. Against the striped melon-beetles use one pint of 

 turpentine in one bushel of lime, applying freely to all parts of 

 the plant, and particularly around the base. This will keep them 

 off in most cases. 



In some of the Pacific States resin washes are much used 

 against scale insects, apparently with excellent success. They 

 have not been as satisfactory when used in the East ; perhaps 

 due to the fact that the insects make thicker scales, or are more 

 completely dormant in the winter. The wash which has given 

 best satisfaction for summer use is made according to the follow- 

 ing formula : 



Resin 20 pounds. 



Caustic soda (seventy per cent, strength) ... 5 pounds. 



Fish oil 3 pints. 



Water sufficient to make 100 gallons. 



