46 SCALE PESTS OF COFFEE 



tons of it were sold through the Department alone and since 

 then its use has become general in South India and 

 Ceylon, wherever a cheap insecticide, easily prepared, is 

 required to deal with sucking insects such as scale 

 insects, mango hoppers, and plant lice. 



Sprayers. — The most satisfactory sprayer to use is 

 the Pressure Sprayer first introduced into South India by 

 the Mysore Department of Agriculture. In this type 

 after the charge has been poured into the sprayer, the air 

 is pumped in until there is sufficient pressure to force out 

 all the insecticide through the nozzle. Both hands are 

 thus free, one to direct the spray and the other to turn 

 the branches so that the spray can reach all the infested 

 parts. In the other types of sprayers this is not pos- 

 sible as one hand is engaged continuously in pumping. 

 The freedom of the second hand is of importance in 

 spraying bushes with the spread of coffee and against 

 insects which are on the under sides of the leaves and 

 therefore not easily reached. 



There are several types of pressure sprayers of which 

 the one originally made by Gebriider Holder has proved 

 the most efficient. Since the outbreak of the war, sprayers 

 practically identical with the Holder sprayers are being 

 manufactured by a number of English firms, but unfortu- 

 nately it has been almost impossible to get them out. 

 These are sold in four sizes of one, two, three and four 

 gallons capacity. A three-gallon sprayer is the njost 

 suitable for estate spraying. The price of these sprayers 

 has risen very greatly since the beginning of the war. 



Spraying. — The two most important considerations 

 in spraying are, (1) that the spray should reach all the 

 insects on the sprayed tree, and (2) that no solution should 

 be wasted. To attain the first object, it is necessary that 

 the insecticide should reach every, part of the plant where 

 the insects are found. Since most bugs are on the under 

 surface of the leaves, the spray has to be directed from 

 below. The top branches have to be lifted up or moved 

 side ways to receive the full spray. The tender leaves 

 and opening buds should receive special attention, 

 Spraying should be done in the direction of the wind and 

 never against it. When spraying is done against the wind, 

 the spray fails to reach the places aimed at and a consider- 

 able quantity is wasted. 



To prevent wastage of solution, in addition to the 



