INSECT PESTS 495 



Caustic Alkali Wash. This mixture is very useful as a winter wash for fruit trees that 

 are infested with American blight, scale, &c. It destroys all insect life with which it 

 comes in contact, also all moss and lichens. It is quite harmless to the trees so long as it 

 is used before the buds begin to open. It is very caustic, and should not be allowed to 

 get on the skin. It will also spoil clothes, so that it should be used on a still day, to 

 prevent it being blown on to the operator when using it. Make it as follows : Dissolve 

 i Ib. of ground caustic soda in a gallon of water, add f Ib. of pearl ash, stir until all 

 is dissolved, and then add 9 gallons of water, and lastly 10 oz. of soft soap which has been 

 dissolved in a little boiling water ; mix thoroughly, and the solution is ready for use. 



Paris Green. This insecticide should always be used with care as it is very poisonous, 

 but it is very useful in killing caterpillars that are injuring the foliage of fruit trees and 

 plants. It is generally sold in a powder, but it is better to buy it as a paste, as it does not 

 then blow about. One oz. should be used with every 12 gallons of water. The mixture 

 must be kept well stirred as the Paris green is very heavy and soon sinks to the bottom. 

 It should be used as a spray, and only enough should be used to wet the leaves and not 

 to make them drip. Paris green should not be used when trees and plants are in flower, 

 or within a month of the fruit becoming ripe. 



In making up these recipes soft water should be used if possible. If hard water must 

 be used add a little soda. 



Gas Lime if applied at the rate of \ Ib. to i Ib. per square yard will kill wireworms and 

 other insects that are infesting the soil, also snake millipedes, but no crop can be grown 

 on the ground for several months after the application. 



Nitrate of Soda is useful when applied as a strong solution in water to the roots of 

 plants. It is very distasteful to insects, &c. , and is a stimulant to the plants. 



Soot when fresh is useful if laid thickly round the plants, and then worked in, for keep- 

 ing grubs, &c. , away from the roots. 



Though it is impossible now to deal with the fungi which attack plants, it should be 

 always borne in mind that if a plant is infested any leaves that fall from it should be 

 collected and burnt, and the plants themselves, if only annuals, should be treated in the 

 same way as soon as there is no further use for them. If only thrown on a rubbish heap 

 or allowed to remain on the ground for some time an opportunity may be given for the 

 winter 'form of spores to ripen and reproduce its species the next season. The 



Bordeaux Mixture. This is the best fungicide for general use. To make it dissolve 

 10 oz. of sulphate of copper in a little boiling water, and add 5 gallons of cold water, slake 

 6 oz. of lime in water, and pour it into the copper solution when cold ; stir the mixture 

 well so as to be sure that all is of uniform strength ; then dip the blade of a bright knife 

 into the mixture for a minute ; if the colour of the steel is unchanged it is all right, but if 

 the blade has a coppery appearance more lime should be added or the mixture will injure 

 the foliage. Another test is to place some of the mixture into a plate, hold it up and blow 

 gently upon it for quite half a minute, when, if a slight scum like a little oil appears on 

 the surface, it is as it should be. For use in connection with Potato disease see page 413. 



