271 



EXPERIMENTS WITH INSECTICIDES ON SCALE 



INSECTS. 



It is so important for the future of tlie Orange industry that Scale- 

 insects should be kept under control, that all should combine in at- 

 tempts to destroy them. 



Experiments are being carried on at Hope Gardens with insecticides, 

 and many formulae have been tried. The following has so far been 

 more successful than all others, and as it is cheap, and easily made, it 

 is hoped that others will experiment with it, and note results. 



Take a perfectly clean and dry bowl of a good size, pour into it half 

 a pint of the cheapest Kerosine, add two pounds of soft soap, and work 

 through the fingers yigorously until both constituents are thoroughly 

 incorporated ; the compound will then be of the consistency of putty 

 and soluble in water. 



It is advisable to mix only sufficient for one spraying, as it loses 

 some of its insecticidal properties if kept for any length of time. It is 

 also advisable to mix it in the sun as the warmth makes the ingredients 

 combine more readily. 



Di solve six ounces of the compound in half a gallon of rain (or boiled) 

 "water that has been warmed by the sun. When dissolved add a further 

 2J gallons of soft water. The insecticide is then ready for use. Spray- 

 ing should be carried out late in the afternoon, thus allowing the in- 

 secticide to remain in solution for a much longer time than if applied in 

 the heat of the day. 



With some scales one spraying is sufficient ; but at other times three 

 successive sprayings, four days between each are necessary to destroy 

 them. 



If the scales readily rub off after the application, it is a sign that 

 they have been killed. Sometimes it happens that the spraying has no 

 effect, — the scales adhere so closely that the insecticidal mixture does 

 not penetrate, and then the scales do not rub off. In such cases the 

 scales must be watched, and after a few days or a few weeks, spraying 

 can be tried again. The best time to attack them is when the young 

 ones have come from the mother scale, and are starting in life for them- 

 selves. In one case a yellow waxy-looking scale was noticed, on which 

 the mixture had no effect until in about 6 weeks it turned colour and 

 became a brown scale, then it was killed. 



If only two or three shrubs in a Garden are affected, they can be 

 treated with a feather, but it is generally necessary to use a spray 

 pump, which can be purchased now in Jamaica. — (See Bulletin, Feb- 

 ruary, 1897.) 



