FOUE IMPORTANT INSECTICIDES. 139 



very poisonous to insects; yet so far as I have tried it does not appear to.be in 

 the least inimical to plant growth. 



This has long been recommended in England and other parts of Europe as a 

 most valuable insecticide. A few years ago, I procured gome and tried it, with 

 almost no benefit. Last summer I secured some more, quite fresh, and found 

 it exceedingly effective. I now think that the material I secured when I 

 first tried it was old and worthless. I have mixed it with water and used it dry 

 as a powder, and in both cases found it very satisfactory indeed. 



Tlie fact that the gas lime procured at one time was worthless, and at 

 another valuable, raises the question of course as to the reliability of this insec- 

 ticide. And the further question of whether we know, because the sample last 

 used was not injurious to the plants, another sample secured at another time 

 and place, might not be very hurtful to them. These are questions which I 

 intend to solve in the future. I Avill now add that the material used this sum- 

 mer Avas entirely fresh. I was so well pleased with its use both ou leaf- 

 eating nisects like the cabbage caterpillar and flea beetles, as well as on the 

 cabbage and radish maggots, that I thought it well to suggest its use to others 

 that they might also experiment with it, and if is as good a remedy as I hope 

 and have reason to believe, may at once have the benefit accruing from its use. 

 There is one signal advantage in this insecticide, it only costs the trouble of 

 getting it, though should it prove valuable this might not remain true very long. 



To use this substance on leaf -eating insects, we may scatter it on as a powder, 

 or mix it with water and sprinkle the plants with it. I have reason to believe 

 that if a little of it is incorporated in the soil in beds where radishes and 

 cabbages are being grown that the destructive maggots will not put in an 

 appearance. We tried it on plants already attacked and found that all the 

 maggots actually touched by the powder were speedily killed. Like the kero- 

 sene emulsion, to give perfect satisfaction, it must be applied as early at 

 least as the flies come to de^^osit the eggs. It is very possible that by scattering 

 this gas lime on our squash vines in June, we might stay the ravages of that 

 dreaded pest, the squash borer. 



There are other remedies that I might discuss. I might also occupy time 

 advantageously in describing some of our new insect enemies, and some of the 

 numerous parasites and predacious insects that are so powerfully aiding us in 

 this insect warfare; but recognizing as I do the great value of the discussions 

 which follow these papers, I ^ive way, that there may be no stint in the time 

 given to the further consideration of this theme, in which you all shall be par- 

 ticipants. 



Mr. Shaw : I have tried for three years to find why we had no fruit on my 

 apple trees. The bark louse has in four years killed four trees for me. They 

 are on nursery trees brought from New York. I killed the lice with kerosene 

 emulsion applied with a force pump. Mr. Darrow did the same to his trees 

 last year and his trees made a good growth. I use a double-barreled force 

 jDump, cost $13. On first application you see no effect, but after a few days 

 their scales shell off from the bark. I use four quarts kerosene, two quarts 

 sour milk, one quart water, mix cold and add sixteen quarts water. 



Prof. Cook: I have tried this milk emulsion and found that it injures the 

 foliage. 



Mr. S. Moody: I have tried weak lye, soap, etc., on my trees and have very 

 few lice. 



Prof. Cook: Soft soap will kill them, but adding the kerosene makes it a 

 surer thing. 



