On the Destruction of Caterpillars on Fruit-trees. 77 



application the trees recovered their natural colour, and grew 

 with their usual vigour. 



A day should be chosen for the operation when little wind 

 is stirring, but particularly when there is no rain : I think the 

 absence of sun, or a cloudy day, preferable for the operation. 



The earlier the remedy is applied after the insect is dis- 

 covered, the better, and if it should be necessary to use it 

 a second time, it must be done before the fruit changes 

 colour, lest it be disfigured by the application of the lime. 

 The lime need not be thrown on thick, but should be well 

 divided with the hand in casting it, so that every part of 

 each leaf be touched. In small gardens, where no engine 

 is kept, a watering pot or a syringe may be used so as to 

 wet every part of the tree. 



Encouraged by my success on the Gooseberry bushes, I 

 tried the lime against the black leach-like insect, or maggot,* 

 which is so destructive to Thorns, Pear, and Cherry trees, 

 and found that wherever the lime touched the animals, if they 

 were wet, it destroyed them : it being difficult to water 

 high standard trees, I took the opportunity very early in 

 the morning, before the dew was evaporated, to apply the 

 powder; slacking the lime over night to have it ready. 

 The powder was tried after a shower of rain, but rain fol- 

 lowing, the operation did not answer ; where however these 

 insects can be got at they are more easily destroyed than 

 those which infest the Gooseberry bushes. Pear trees 

 against walls are often injured by these leach-like insects, 

 but they can be watered and limed without difficulty. 



I have tried lime-water thrown by the garden-engine, 



* It is the larva of a dipterous insect, or two-winged fly. Sec. 



