CUT-WORMS. THE INJURIES THEY DO. and studded with little rust-colored points. The insect remains in the cocoon from eighteen to twenty days and then comes forth in its perfect state. Like other caterpillars of the group to which it belongs, this is a general feeder, subsisting upon low herbaceous plants of almost every kind, and on a pinch feeding also upon the leaves of trees and shrubs. An incident related by Duponchel (Hist. Nat. des Chenilles), shows how able it is to sustain itself upon any substance of a vegetable nature which is sufficiently soft for it to masticate. Having forgotten one of these caterpillars which he had wrapped up in a paper envelope and inclosed in a wooden box, he afterwards discovered it had nourished itself upon the paper, as was proven by the dry pellets of excrement in the box, and had after this completed its transformations, producing a moth which was a dwarf in its size but with very bright colors. Some curious facts are reported, showing the colors of this moth to vary according to the quality of the food on which the caterpillar is nourished. Thus, if it be fed upon lettuce or other vegetation of a similar succulent nature, the colors of the moth are more dim and pale than when it is reared on substances which are less watery. The German collectors are said to obtain the variety having the under wings black by forcing the caterpillars to feed exclusively upon the leaves of the walnut. Some of the French, however, are stated to have tried this without success. It may be that some concurring atmospherical influences, some peculiarity of the season, is also necessary to insure the particular result. The species certainly presents a most interesting subject for the experiments of amateurs. 12. CORN CUT-WORM, Agrotis nigricans, Linn., Var. Maizi. (Lepidoptera. Noctuidae.) Plate 4, fig. 2, 3. In June, severing the young Indian corn and other plants, half an inch above the ground, by night, and by day hiding itself slightly under the surface; a thick, cylindrical, gray worm an inch and a quarter long, with rather faint, paler and darker stripes, the top of its neck shining black with three whitish stripes. The insects from which our farmers experienced the greatest vexation. and injury the past season (1863), were the Cut-worms-the same worms which are sometimes called corn-grubs, and which in English agricultural works are termed surface grubs or surface caterpillars. The name Cutworm,, however, is most commonly given to them in this country, both in print and in common conversation, and appears to be the most appropriate and best term by which to designate them, having allusion as it does to a habit which is peculiar to these worms, namely, that of cutting off tender young plants as smoothly as though it was done with a keen-edged knife. These Cut-worms are among the most important injurious insects of our country. It is mostly in our fields of Indian corn and in our gardens that their depredations are noticed. They are so common as to occasion some losses almost every year; whilst every few years they make their appearance in such numbers as to nearly or quite ruin the corn-fields, obliging the proprietors to plant their ground a second and even a third time, or to replow it and sow it with a different crop. Thus, in consequence of the pre CUT-WORMS. EARLY NOTICES AND RECORDS OF THEIR INJURIES. sence of this worm in our country, the labor of the husbandman is frequently doubled to obtain from his land a crop either materially diminished in amount or of a less valuable kind from that which he would be able to harvest were it not for this enemy. The attention of the farmers of our State was this past season prominently directed to the rearing of flax, and a breadth of land was given to this crop far exceeding what has ever before been assigned to it. But soon after the young flax appeared above the ground, these Cut-worms began their depredations, feeding upon and wholly consuming the small tender plants to such an extent that many fields. had large patches in them which were eaten perfectly bare, whilst in others 'the crop was totally destroyed. Many of our injurious insects are new pests which have but recently been observed in our country. But these Cut-worms appear always to have been here, depredating upon and despoiling the cultivated crops in centuries gone by, the same that they are now doing. Before European settlers arrived upon this continent, the cornfields of the Indians are said to have been ravaged at times by these worms, this being of all others a disaster to them of which they were most fearful, and one which they felt themselves wholly powerless to avert, their only resort for protecting their fields from this calamity being that indicated in the lines of the poet: "Draw a magic circle round them, So that neither blight nor mildew, Shall pass o'er the magic circle." And this is well known to have been a casualty of frequent occurrence, all along since the soil of our country has been cultivated by civilized men. In those diaries which have occasionally been kept in different parts of our land by persons who have been curious to preserve a record of local incidents of interest, we are sure to meet ever and anon with the statement, "Indian corn was this year greatly injured by the worms," "The season was wet and cold, and the worms made extensive ravages on the corn," and other entries of the same purport. From one of these sources we learn that a century ago there had been a distressing drouth in 1761, followed by an unusually long and severe winter and a late spring. "When at last the corn was planted, millions of worms appeared to eat it up, and the ground must be planted again and again. Thus many fields were utterly ruined." (Flint's Second Report, Mass. Board of Agriculture, p. 40.) It, however, may have been the Wire-worm which occasioned at least a pbrtion of the destruction here related, for usually when one of these worms is numerous the other is so likewise. It is unnecessary to mention other years in which we have little more than the mere fact stated that these corn worms were very injurious. In addition to such manuscript mementoes, the published allusions to these pests date far back. Upwards of seventy years ago, when the old Agricultural Society of our State was first organized, in a circular which the Society issued, containing inquiries upon different topics on which information was solicited, the first query respecting insects was, "Is there any CUT-WORMS. HAVE NEVER YET BEEN INVESTIGATED. way of destroying the grubs in corn and flax?" No answer to this inquiry, of sufficient importance for publication, was received. But, although these Cut-worms have always been such a formidable foe in this country, against which the cultivators of the soil have had to contend, they have not, down to the present day, been subjected to any careful scientific examination. It was formerly supposed they were all of but one kind, one species of insect. In our day it has been ascertained that they are of several different kinds, and that they are bred from a particular group or family of millers or moths, of a dark color, which fly about in the night time and remain at rest and hid from our observation during the day— most of them belonging to the genus named Agrotis by naturalists. But the observations which have been made upon these Cut-worms have been so hasty and superficial, that, when we see one of these worms cutting off the young corn in our fields or the cabbage plants in our gardens, we are unable to give it its exact name; we are unable to say what particular species of miller or moth it is which has produced that worm. All that has yet been done towards a scientific investigation of this subject may be narrated in a few words. Upwards of forty years ago, Mr. Brace, of Litchfield, Ct., in a short article published in the first volume of Silliman's Journal, gave what he evidently regarded as a sufficient elucidation of this matter. It appears that in a patch of ground planted with cabbages, where the worms had been numerous, he found their pupa to be common, lying a few inches below the surface, just after the worms had disappeared. From some of these pupa he obtained the miller or moth. In the article alluded to, he merely describes this miller as being the insect which produces the Cut-worm, naming it the Phalena devastator or the Devastating miller. As he supposed all the Cut-worms were of one kind, he gives no description of the worm from which this miller is produced. And thus it remains unknown to this day what the characters and appearance of the worm are which belongs to this miller which Mr. Brace described. Some ten years after this, Dr. Harris, one season, gathered a number of full grown cut-worms from different situations, to breed the moths from them; but what is most surprising, he took no notes of the differences in the appearance of these worms. He obtained from them four different moths in addition to the one which Mr. Brace had previously obtained. These he names and describes, but is unable to give any account of the worms which belong to either one of these species. In the Second Report which I presented to this Society, I gave very exact figures of the miller which Mr. Brace described, and of two others of the most common millers of our country belonging to the same group; and I also described five of the cut-worms which I had noticed as being common kinds in our cornfields and gardens. Finally, in my Third Report I was able to give an account of one of our cut-worms, and the moth which was raised from it. And this is the posture in which this subject now stands. Seven of the moths or millers of our country, which produce cut-worms, have been named and described. But only one of them is known to us in its larva state. We also know that at least five other cut-worms in addition to this one, are formidable enemies to us, depredating every year, more or less, upon the young plants in our fields and gardens, but we know not the species to which they respectively pertain, and consequently are unable to distinguish either of them definitely, by giving to it its correct name. I have for a great many years regarded these cut-worms as a most important subject requiring to be elucidated. And accordingly, almost every year, upon meeting with some of these worms, I have written in my notes a particular description of them, and have endeavored to feed and rear them to their perfect state, but without success. They are very intolerant of confinement, especially when they are not grown to their full size. Upon discovering that they are imprisoned, they lose all relish for food, and become intent on one thing only, namely, to find some orifice in their prison walls through which to escape. Accordingly, when the shades of evening arrive, they come out from the earth in the box or pot in which they are placed, and crawl hurriedly and anxiously around and around, the whole night long, as I have found on going to them with a light. The vegetables transplanted into the box for them to feed upon remain untouched. In this manner, they in a few nights wear their lives away, and are found lying stark and stiff on the surface of the dirt of their cage. From the experience I have had, I regard them as among the most difficult insects which I have ever taken in hand to feed and rear from their larva to their perfect state. It had accordingly become evident to me that a suitable knowledge of these Cut-worms could never be gained in the manner I had attemptedby casual observations made at moments snatched from other investigations. It was only by making them the leading subjects of examination; devoting to them ample time and care and vigilance; studying them as they were growing up in the fields and gardens; watching them from day to day, there, in their natural haunts, until they became fully matured and were done feeding, and then placing them in cages to complete their transformations and reveal to us what they are in their perfect states; I say, it had become evident to me that it was only in this manner that the requisite knowledge of these creatures could be obtained, to prepare such an exact history of them as their importance and the advanced state of science at this day demand. I have, therefore, for several years, had it in contemplation, when a season occurred in which these worms were numerous, to devote my chief attention to them. And accordingly, on becoming aware last May, that these worms would be quite common in my vicinity, I resolved to make them the subjects of special investigation. And I now proceed to give a summary account of these insects and their habits, and the progress which the researches of the past season has enabled us to make towards a more full and exact knowledge of them. It is in midsummer, mostly in the month of July, that the moths or millers come abroad and lay the eggs from which the cut-worms are bred. CUT-WORMS. YOUNG WORMS IN AUTUMN. FALL PLOWING TO DESTROY THEM. The eggs are dropped at the surface of the ground, around the roots of grass and other herbage. The worms hatch and feed during the autumn, coming abroad by night and eating the most tender vegetation which they are able to find, and during the daytime withdrawing themselves under the ground to hide from birds and other enemies, and feeding upon the roots of the vegetation which they there meet with. Grass appears to be their favorite food, and its young, tender blades and rootlets furnish most of these worms their subsistence through the first stages of their lives. During the autumn the earth is so profusely covered with vegetation and these worms are so small that no notice is taken of them or the trifling amount of herbage which they then consume. They become about half grown when the cold and frosty nights of autumn arrive, whereby they are no longer able to come out to feed. They then sink themselves deeper than usual into the ground, going down to a depth of three or four inches; and there, each worm, by turning around and around in the same spot, forms for itself a little cavity in which to lie during the winter; and it then goes to sleep, and lies torpid and motionless as though it were dead. The soil at the depth where these worms are lying, very slowly and gradu ally becomes colder and colder as the winter comes on, and at length freez‐ ing, these worms reposing in it are also frozen. And when the warmth of spring returns, the ground thawing and becoming warm in the same gradual manner, these worms slowly thaw and awake from their long sleep and return again to life. The case is analogous to what occurs with ourselves when we have a finger or a foot frozen. On coming into a warm room, if we keep the frost-bitten part covered with snow or immersed in ice-cold water, whereby it very slowly thaws and the circulation gently and gradually returns to it, the part readily recovers; whereas, if instead of this, we hold it to the fire and thaw it suddenly and abruptly, high inflammation and gangrene follows, and we lose the limb. And so, if these cut-worms lying in the ground should be suddenly frozen or thawed, it would be fatal to them. This brings to our view an important measure which is much practised for the purpose of destroying these worms and securing the corn crop from their depredations. Our farmers quite generally endeavor to break up their planting ground in the autumn, rather than in the spring, under the idea that they hereby disturb these worms in their winter quarters, and expose them to the cold and frost, whereby a considerable portion of them are destroyed. And I believe it is the general experience of our farmers that corn planted upon ground which has been thus broken up in the autumn is less liable to be injured by these worms, than where it has been broken up in the spring. But these worms, in common with all other insects, continue to be active in autumn so long as the weather remains warm. It is not till they feel the chill of the autumn frosts that they retire into their winter quarters. Therefore, if the ground be broken up early in autumn, when the weather is still warm and the worms are in full life and activity, it can be of little, if any avail, for the purpose intended, as they will readily crawl into the ground to the depth which they require for their 1 |