C. B. J., Camden, Del., writes: The pear slug occasions great trouble and loss in this section. Is there no method of preventing their invasions? People here, very generally, I believe, know of the expedient of dusting with different substances; but this process I have found tedious, not always practicable nor effectual.

If you could put our fruit growers in possession of a preventive of these attacks you would confer a great favor, and I should be glad to help make it known in connection with your name. Or perhaps you could communicate a specific through your Monthly.

I am not much acquainted with the natural history of this pest. I do not suppose it ascends from the ground, as the first generation of a. season that appears on the leaves is very minute. Perhaps in the case of small trees, the emanations of salt placed at the proper time in the trees in small bags would effect something. I have read that Iodine would attract them.

In small nursery trees, I have found it best to jar them off after they had advanced somewhat in growth,and send the cultivator over the ground.

[Does any one know of any thing better than dusting or sprinkling, as our correspondent says these processes are tedious. But we know of no other. - Ed. G. M].