INSECTS. 331 



necessary in making this mixture of a proper strength, for, if too 

 strong, it is injurious to the plants; and the experiment does 

 not seem, as yet, to have been conducted with sufficient care to 

 insure safety and success. Dusting lime over the plants when 

 wet with dew has been tried, and found of some use ; but this 

 and all other remedies will probably yield in efficacy to Mr. 

 Haggerston's mixture of whale-oil soap and water, in the pro- 

 portion of two pounds of the soap to fifteen gallons of water. 

 Particular directions, drawn up by Mr. Haggerston himself, for 

 the preparation and use of this simple and cheap application, 

 may be found in the * Boston Courier,' for the 25th of June, 

 1841, and also in most of our agricultural and horticultural 

 journals of the same time. The utility of this mixture has 

 already been repeatedly mentioned in this treatise, and it may 

 be applied in other cases with advantage. Mr. Haggerston 

 finds that it effectually destroys many kinds of insects ; and he 

 particularly mentions plant-lice of various kinds, red spiders, 

 canker-worms, and a little jumping insect, which has lately 

 been found quite as hurtful to rose-bushes as the slugs or young 

 of the. Saw-fly. The little insect, alluded to, has been mis- 

 taken 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), described in a 

 former part of this essay, and, like the leaf-hopper of the bean, 

 entirely of a pale-green color." 



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

 ral 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 satisfactory 

 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 commit- 

 ting its depredations on the foliage. 



" WHALE OIL SOAP, dissolved at the rate of two pounds to fifteen gal- 

 lons 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 T 



