Who can estimate the vast extent of insect life, especially in cities ? None but the careful cultivator, who takes an honest pride in the health and, of course, the cleanliness of his plants, can at all conceive of the amount and infinite variety of the depredators, to whose attacks they are daily and hourly liable. There is scarce a plant which has less than six or eight special enemies, while of the coccus, worms of numberless variety, and caterpillars of all shapes, colors, and sizes - a whole army is continually striving to destroy our labors and our hopes.

Whence this worse than Egyptian plague, and whence their origin! Their present condition is but one aspect - one phase of their existence; for their propagation and diffusion Nature has provided a seperate and distinct life; they are metamorphosed into a new and higher state of being. Moths, millers, and flies, destructive though they may be, are but the representatives and propagators of enemies still more rapacious. Each moth, each miller, and each fly, as a general fact, is the precursor and parent of maggots, worms, and caterpillars innumerable.

What reliance then can be placed upon the efforts of the few birds found in a city for the destruction of these legions \

For many years I have made it a point to destroy forthwith, upon their first appearance, all insects which dared to manifest themselves in my garden. This has caused me no small labor; and the most discouraging feature of the whole is, that during the season of vegetation the work is never done. Some new phase of the annoyance is constantly occurring - some new and more destructive enemy requires constant extermination. I have also provided nests for our various birds, and have fed them until my garden has become the home of the blue bird, the robin, wren, humming bird, oriole, yellow bird, the warbler, and various others of our sweet songsters.

The success of my conflicts with the flies in my house has been more encouraging. By destroying all which first arrived I have been able to keep them, not entirely extinct it is true, but yet somewhat like angels' visits. Since the experiments I am about to detail scarce a fly can be found in my house.

This season I determined not only to destroy all creeping things which should infest my plants and flowers, but also to carry the war of extermination directly into the homes and families of my adversaries. For this purpose I procured twenty-four wide mouthed bottles. They hold nearly a quart each - are hung perpendicularly on the fence around my garden, and are about three-fourths filled with two parts of molasses and one of vinegar. Each evening they are all emptied into a wire seive (the liquor unconsumed being preserved for further use) and then refilled. All this takes time, as any operation must which has to be repeated twenty-four times; but it is all accomplished by one person, and the flies measured and buried in about twenty minutes - less time than would be required in finger-picking the offspring of any dozen of the millers destroyed.

One fact in reference to this matter is deserving especial notice. If the bottles are emptied and refilled at evening a large number of millers of all sizes and kinds will be caught. One morning I counted over fifty caught the previous night, some of them very large, in one bottle. That number as an average, and for aught I know a fair one, would give an aggregate of twelve hundred caught in a single night.

The result thus far has exceeded my expectations. The largest quantity caught in any one day was eight and a half quarts. The average for the last seven days is six quarts - that is, I have actually caught during the last week forty-two solid quarts of millers, beetles, and flies. This result has been attained in my small garden, where constant and thorough measures have been persevered in for years to destroy all insects. How much more might be accomplished in localities where they have been permitted to increase to their full capacity.

Can any one calculate the vast array of depredators, which would have been propagated from these more than five pecks of moths, millers, beetles, and flies. We have in New Haven three thousand and seven hundred dwelling houses with yards and gardens attached, beside our three hundred and sixty stores and one hundred and eighty manufactories. Six quarts from each of these houses would give a daily aggregate of over six hundred and ninety-three bushels, or four thousand eight hundred and fifty-six bushels of solid beetles, millers, and flies, caught in one week.

How much of annoyance and misery to men and animals, and injury to plants and fruit might thus be prevented, and how comparatively slight the labor. Probably more time and labor is now actually expended in this locality in the destruction of the offspring than would in this way be necessary to exterminate the race.

Sometime since you remarked, in answer to a correspondent, that manure buried eight inches deep in the soil was of no value.* That must depend upon the nature and condition of the soil. Where it is light and friable and well worked, the roots, according to my observation, pervade the whole soil, however deep. In burying the flies I have caught recently among my corn, planted June 7th, I find the ground already full of roots to the depth of over a foot. True my soil is of unusual depth, as I have it carefully dug and thoroughly worked from two feet to thirty inches deep throughout. I find that the roots of my vegetables and plants avail themselves of its whole depth before they arrive at maturity.

* We do not remember having made such a statement, and certainly Should not wish to be so understood, for we know very well that manure baried eighteen inches instead of eight would be valuable under certain circumstances.

[We are glad to see observing men in all parts of the country turning their attention to a study of the habits of insects, and the best methods of repelling their attacks upon vegetation. It is a fact that every year we are called upon to note the arrival of some new enemy to the products of our orchards and gardens, and the cultivator who fails to make himself acquainted with them, and the most successful modes of resisting and destroying them, will find himself as utterly helpless as would a mariner in the trackless ocean without a compass.

We thank Mr. Robinson for the account he has given us of his labors. We have seen the same mode of trapping successfully pursued by others, and are satisfied that every individual might do much in their way to relieve their premises from such annoying pests. In this connection we cannot urge too strongly the necessity of the prompt and complete destruction of every fallen fruit. Not a single specimen should be left on the ground over night Children can do this work as well as men, and it will aid very materially, as we know by experience, in diminishing the number of insect depredators. - Ed].