642 



The Apple Blossom Weevil. 



[Oct., 



The spray which yielded the best results at Long Ashton 

 was an unstable paraffin emulsion. Numerous trials with 

 different proportions of the mixture, were made, the greatest 

 measure of success being obtained with : — 



Potash soft soap 5 per cent. 



Paraffin 10 per cent. 



The fact that paraffin readily comes out of this emulsion is a 

 drawback to its use since it necessitates the mixture being 

 kept agitated while spraying, but the instability is essential 

 since it is by the paraffin that the insect is killed. The 

 difficulty is overcome where a good mechanical agitator is 

 used. The spray kills by contact and therefore needs to be 

 applied only to those situations on the tree where the weevils 

 -are likely to be wintering. Canker spots, crevices, growth 

 cracks and rough bark should be well drenched and a good 

 force kept behind the jet. Where well wetted with the spray 

 the weevils are killed within a quarter of an hour. For ordinary 

 bush trees on paradise stocks, and reaching a height of about 

 6 ft., one gallon of the spray is sufficient for about three 

 trees. For young and small trees a Knapsack spraying outfit 

 would probably be found quite satisfactory. The spray should 

 l^e applied towards the end of March. 



Where lime-sulphur is used annually as an insurance spray 

 a peculiar dry condition of the rough bark and crevices arises, 

 and this condition is such that the sites are quite unsuitable 

 B,s winter quarters for the Apple Blossom Weevil. This sug- 

 gests that where the use of lime sulphur is regularly followed 

 good results might be obtained by banding. 



In addition to the treatments indicated, measures that will 

 tend to make for an increasing freedom from the pest are 

 keeping the trees clear of rough bark, mosses and lichens, and 

 observing the rules of clean husbandry in the plantations. 



Where practicable, as indicated in the leaflet on the Apple 

 Blossom Weevil issued by the Ministry of Agriculture, collect- 

 ing the capped blossom, destroying the weevil and liberating 

 parasites are measures which, if followed systematically, may 

 have very far-reaching results in controlling the weevil. 



At present it is advisable that where great losses occur 

 annually the methods herein indicated should be used either 

 in their entirety or else modified to suit the particular circum- 

 stances. No one method is likely to give complete control 

 but where two or three are employed in conjunction in planta- 

 tions a reasonable freedom from this pest is obtainable. 



