CHAPTER XV 
Contact InsEctTicipEs — For Sucxine INsEcTS 
Lime-sulphur Solution 
Live sulphur is a chemical combination of lime and sulphur, and 
kills insects by its caustic properties. At the same time it has con- 
siderable value as a fungicide, for the control of such plant diseases as 
apple scab. 
The material is used both as a winter spray, when the trees are dor- 
mant, and as a summer spray, the latter for fungus diseases; but the 
solution for summer use is much weaker. Material of the proper 
strength for winter use must never be sprayed on trees in leaf as it 
will burn the foliage. 
The best time to apply the winter strength of lime-sulphur solution 
is in the early spring, just before the buds swell. For San José scale 
and for leaf blister mite, two insects for which this material is especially 
useful, this is the most effective season. It may be applied in the fall, 
however, at any time after the leaves drop. 
There are three ways of preparing the winter wash of lime sulphur: 
by diluting the commercial concentrated solution now on sale in stores 
to the required strength; by making a concentrated solution at home, 
and properly diluting when needed; and by making at home a solution 
which when finished is ready at once for use. These will be described 
in order. 
Commercial Lime Sulphur 
Commercial concentrated lime sulphur is a clear, reddish brown liq- 
uid. It has been placed on the market by a number of manufacturers, 
and is obtainable practically everywhere. 
For use, this material simply is diluted with water. The amount of 
water to be added always is indicated on the container in which the 
liquid comes. But if it is desired to test the strength, this can be done 
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