Field Spraying with undiluted Paraffin Extracts of Pyrethrum againstAntestiaandLyguson Coffee in Kenya

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Abstract
The application of an undiluted paraffin extract of pyrethrum for controlling Antestia and Lygus simonyi on coffee trees is described.(1) The spray is applied with a small hand “ atomiser,” using 20 cc. of extract to a tree, and spraying under a cloth cover.(2) Tables are given with detailed figures in which the different methods of application may be compared. The kill of Antestia brought down by the most favourable method is 99%.(3) The proportion of insects brought down by the spray is in the neighbourhood of 96%. It appears that in practice a kill not much below 95% should be possible.(4) Of the Lygus on trees sprayed, 99% were brought down and the kill of these was complete.(5) The method is a dual control for Antestia and Lygus, and examples are given of trees sprayed when both these insects were present in serious numbers.(6) An experimental field spraying against Lygus is described in detail. It was shown that the numbers of Lygus could be kept below two to a tree by this spraying, and the proportion of fruit set on the sprayed block to that on the control was 3 : 2, indicating an increase of about 8 cwt. an acre.(7) The technique of the experimental sprayings, by which the detailed figures in the tables were obtained, is described. It is believed that these methods will be of more extended value in the experimental testing of sprays in the field.