PKACTICAL ENTOMOLOGY. 449 



infested tree to look as if severely 

 scorched; after the last moult the 

 slimy covering is lost, and the worms 

 become yellow. In July and August 

 they go into the ground two or three 

 inches and pupate ; in two or three 

 Pig. 14. weeks the flies come forth and lay the 



eggs for a second brood. Besides the cherry this insect infests pear trees, 



and is said to sometimes attack the mountain ash. 



EEMEDIES. 



There is a small parasite which kills a great many of the eggs. Among 

 artificial remedies the one which has been recommended for many years past, 

 is that of throwing road dust or ashes over infested trees; this sticking to 

 the slimy coverings of the worms has been supposed to kill them. But some 

 experiments made by the able editor of the Canadian Entomologist, Mr. Wm. 

 Saunders, of London, Out., quoted in the report of Prof. Forbes above 

 j'eferred to, throw much doubt upon the efficacy of this time-honored rem- 

 edy. They are as follows : 



"As soon as the slugs were observed at work in the spring, they were treated 

 to a plentiful supply of dry sand, thrown up into the higher branches with a 

 shovel and shaken over the lower ones with a sieve, which stuck thickly to 

 their slimy skins, completely covering them up. 



''Thinking we must have mastered them by so free a use of this long-trusted 

 remedy, we took no further heed of them for some days, when, to our 

 surprise, they were found as numerous as ever. The next step was to test 

 this sand remedy accurately, to see what virtue there was in it. Several small 

 branches of pear trees were selected and marked, on which there were six 

 slugs, and these were well powdered over — entirely covered with dry sand ; on 

 examining them the next morning it was found that they had shed the sand- 

 covered skin, and crawled out free and slimy again. The sand was applied a 

 second and third time on the same insects, with similar results; and now, 

 being convinced that this remedy was of little value, they were treated to a 

 dose of hellebore and water, which soon finished them. Ashes were now tried 

 on another lot, the same way sand had been, with very similar results." 



Apropos of the above, some experiments I recently made upon the subject may 

 be of interest. Eighteen leaves having slugs upon them were marked and the 

 slugs thoroughly dusted with fresh wood ashes. Twenty-eight hours after- 

 wards, eight had either wholly or partially shed the ash-covered skin, one was 

 still covered but alive, and nine had disappeared. It is probable that the 

 latter had left the leaves on which they were, to crawl to neighboring leaves. 

 In order to test this, a number of leaves were marked which had slugs upon 

 them, and the neighboring leaves searched to see that no slugs were upon them. 

 Those on the marked leaves were now dusted with road dust, and when visited 

 twenty-four hours later, nearly all which were missing from the marked leaves 

 were found on neighboring leaves, which had none on them before ; thus show- 

 ing that the insects had found the dust-covered leaves distasteful, and had 

 emigrated to greener pastures. That they were the slugs dusted was usually 

 evidenced by an occasional particle of dust still adhering to them. 



Pyrethrum was found to be very efficient in destroying these slugs, applied 

 either in powder or solution. Experiments on individual slugs seemed to 

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