A. J. Downing, Esq

As as it appears by a writer in the last number of the Horticulturist, that Mr. Longworth, of Cincinnati, has not as yet succeeded in preventing the attacks of the curculio, and that his theory is wrong; that the instinct of the insect teaches it not to deposit its eggs in the fruit of trees paved underneath, or those leaning over water, or in any such situations, where its eggs cannot be hatched, or the grub protected during its transformation, I must beg him, as well as all the unsuccessful cultivators of smooth skin fruit, not to despair, for there is a remedy at hand, and a very simple one, too.

To wit - (for facts are all that are wanted in this matter,) having about twenty plum trees, which have blossomed freely for the last six years, but have never ripened any fruit, I was induced, by reading a notice in the Horticulturist last year, of the efficacy of lime, to try two trees, by syringing them with white-wash made of unslaked lime, with a handful or two of flour of sulphur mixed through it.

Just after the fall of the blossom, I observed that much of the fruit was stung. Then, in order to give the lime and sulphur a fair chance, I shook the trees, and gathered about thirty curculios, after which each tree was syringed with a pailful of white-wash and the above quantity of sulphur, which was repeated twice more, allowing three days to intervene between each application.

I am now happy to state, that one of the trees is so heavily laden with plums, that I will be obliged to prop the limbs. It is a common variety, but however, I invite all those who are inclined, to come and gee it, as it is a rare thing in these parts, whore even common plums are almost unknown. The trees stand in a soil the best adapted for the nursery off all kinds of insects, being warm, dry, and sandy.

I have observed that the syringing not only checked the ravages of the curculio themselves, but destroyed the vitality of their eggs deposited, and thus insures the fruit, even though it had the scar of the puncture already upon it. Truly yours,

Thos. W. Ludlow, Jr.

Yonkers, N. Y., August 13,1851.

We are glad taget so straight-forward an account of a successful experiment, from a correspondent who is a pains-taking horticulturist, and whose accuracy may be relied on. It will be remembered that some of the lime-wash experiments have failed - but so far as we know, Mr. Ludlow's addition of sulphur is new, and may prove more effectual. Ed.