INSECTS INJURIOUS TO PLANTS. 87 
for a species of Thrips, or vine-fretter; it is, however, a 
leaf-hopper, or species of Zettigonia, much smaller than 
the leaf-hopper of the grape-vine (Zettigonia 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, Esg., President of the Massachusetts Horticultural 
‘ Society : 
“ Sir,—Having discovered a cheap and- effectual mode of destroying 
the Rose 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 O11 Soap, dissolved at the 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 find, 
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 the engine, or the nose of* 
the 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 
foree as 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 good 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. : 
