1918 ENTOMOLOGICAL SOCIETY. 43 



Prof. Caesak: In the case of Black Leaf 40 I tried it decidedly strong, and 

 what is more, I put the insects all together in a tight-fitting box so that the 

 fumes could not evaporate easily, and brought them home packed very closely. 

 The fumes had no effect at the end of two or three hours, and they were strong 

 enough to have acted in a few minutes. 



Dr. O'Kane: We did some work this summer along the same lines of 

 contact sprays for leaf-miners, chiefly the Apple Leaf-miner. This work was 

 done on quite a large scale, an assistant starting in spring and remaining 

 all summer on the work of penetration of contact insecticides. We worked the 

 previous winter in the laboratory, shaping our results as far as possible. Of 

 course apple is not the same as blackberry, but I may tell you our results. We 

 used a great many different kinds of material including Black Leaf 40, up to 

 1-50; kerosene emulsion up to 35 per cent.; Black Leaf 40 with soap; lime 

 sulphur at various strengths up to that which burned the tissue. We also used 

 chemical reagents. We ti'ied these through two generations of the Leaf-miner, 

 the first spray when the Miner just hatched, the second when it wp.s 14 ^^- loiig? 

 and the third when it was full grown. We made no penetration whatever into 

 the mines with any substance, except through advantageous openings. If the 

 Miner happened to be next to the mine where there was a good puncture, it 

 got killed; if it was in the middle of the mine it did not get killed. If it was 

 at the far end of the mine it would not be harmed in the least unless the 

 application was sufficiently strong absolutely to destroy the leaf itself, when, of 

 course, the miner was killed too. Pupation would go ahead as usual. As I 

 say, if there happened to be an opening or puncture the material would penetrate, 

 but if there was no sudh puncture the Miner had a perfectly satisfactory and 

 efficient shelter. I am not certain with regard to elm leaves, but this prevails 

 in the case of apple leaves. 



Prof. Caesar : May I ask a question and suggest an answer ? I want a 

 whole lot of information on how to control slugs. 



The President: This has been a most serious problem with nearly everyone 

 on account of the wet season. 



Mb. Gibson : At Ottawa this year we have been using air slaked lime. 



Prof. Caesar: Have you tried hydrated lime? 



Mr. Gibson : No ; only ordinary lime. 



Prof. Caesar : I found last week or the week before when making some 

 further experiments with hydrated lime that at this time of the year it will 

 kill slugs, but whether it would kill them earlier in the seas&n I do not know. 

 I do not know whether it would have any injurious effect on the foliage, say 

 of beans. Lime sulphur if applied very stronsr will kill slugs, but it has to be too 

 strong and will injure foliaafe. Hydrated lime when it comes in contact with 

 a liquid forms a pasty substance. I should like to know if anyone else can 

 suggest any other remedy. 



^ Dr. Corcoran : Last season in the garden everything was eaten up by slugs 

 around Notre Dame de Grace. Almost all the lettuce and cucumber patches were 

 spoilt, and even pumpkins were eaten. We would find a pumpkin with a good- 

 sized hole eaten in it by slugs. We tried hand-picking, bnt that was the only 

 remedv we tried. How is the lime applied? 



Prof. Caesar: You can applv the lime in the eveninof when the sluflfs are 

 at work. They work on top of the leaves and by dustin<r you can set the lime 

 in contact with them. T think this is better than applying it in liquid form, 

 and would have a more lasting: effect. 



