INSECTS INJURIOUS TO PLANTS. 87 



for a species of Thrips, or vine-fretter ; it is, however, a 

 leaf-hopper, or species of Tettigonia, much smaller than 

 the leaf-hopper of the grape-vine (Tettigonia vitis), de- 

 scribed in a former part of this essay, and, like the leaf- 

 hopper of a bean, entirely of a pale-green color." 



" To M. P. Wilder, Esq., President of the Massachusetts Horticultural 



Society: 



" Sir, Having discovered a cheap and effectual mode of destroying 

 the ftose Slug, I wish to become a competitor for the premium offered 

 by the Massachusetts Horticultural Society. After very many satisfac- 

 tory experiments with the following substance, I am convinced it will 

 destroy the above insect, in either of the states in which it appears on 

 the plant, as the fly, when it is laying its eggs, or as the slug, when it is 

 committing its depredations on the foliage. 



" WHALE OIL SOAP, dissolved at tlie rate of two pounds to fifteen gallons 

 of water. I have used it stronger, without injury to the plants, but find 

 the above mixture effectual in the destruction of the insect. As I tind, 

 from experiments, there is a difference in the strength of the soap, it 

 will be better for persons using it, to try it diluted as above, and if it 

 does not kill the insect, add a little more soap, with caution. In corre- 

 sponding with Messrs. Downer, Austin & Co., on the difference in its 

 appearance, they say: 'Whale Oil Soap varies much in its relative 

 strength, the article not being made as soap, but being formed in our 

 process of bleaching oil. When it is of very sharp taste, and dark ap- 

 pearance, the alkali predominates, and when light-colored and flat 

 taste the grease predominates.' The former I have generally used, 

 but have tried the light-colored, and find it equally effectual, but requir- 

 ing a little more soap, say two pounds to thirteen gallons of water. 



" Mode of Preparation. Take whatever quantity of soap you wish to 

 prepare, and dissolve it in boiling water, about one quart to a pound; in 

 this way strain it through a fine wire or hair sieve, which takes out the 

 dirt, and prevents its stopping the valves of thq engine, or the nose of 

 tbe syringe, then add cold water, to make it the proper strength, 

 apply it to the rose-bush, with a hand-engine or syringe, with as much 

 force a.s practicable, and be sure that every part of the leaves is well 

 saturated with the liquid. What falls to the ground, in application, will 

 do srood in destroying the worms and enriching the soil, and, from its 

 trifling cost, it can be used with profusion A hogshead of 136 gallons 

 costs forty-five cents, not quite four mills per gallon. Early in the 

 morning, or in the evening, is the proper time to apply it to the plants. 



" As there are many other troublesome and destructive insects the 

 above preparation will destroy, as effectually as the Rose Slug, it may be 

 of benefit to the community to know the different kinds upon which I 

 have tried it with success. 



