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TOBACCO-WORM. THE NORTHERN AND SOUTHERN SPECIES. with which we have become more fämiliarly acquainted from seeing it so frequently upon the tomato vines ever since this vegetable came into general cultivation in our gardens. And it has obtained the names Potato-worin, Tomato-worm, and now Tobacco-worm, as it occurs upon one or the other of these plants, most persons supposing it to be a different insect in each case. These three plants are closely related to each other, all pertaining to the same Natural Order, SOLANACEE, and this insect feeds upon cach of them without appearing to manifest any preference for one over the other. It feeds equally well, also, upon other species of the genus Solanum, to which the potato pertains. I once met with two fullgrown worms upon a vine of the bittersweet (Solanum Dulcamara) which was growing so distant from any potatoes that it was evident they could not have strayed from that plant, but must have come from eggs which the parent had laid upon this vine, knowing it to be perfectly adapted for nourishing her young. It is probable that it can also nourish itself upon the stramonium, henbane, and most other plants of this Natural Order.
The tobacco-worm which is common at the South and such a great pest to the plantations there, is a different species, but so closely like this in its size, colors, markings and habits, both in its larva and perfect state, that the two insects were for a long time confounded together. It is now just a century ago that the miller or moth of the southern tobacco worm was scientifically named Sphinx Carolina by Linnæus; and it was fifty years later in 1802, that our insect was separated as a distinct species by Mr. Haworth, who gave it the name Sphinx 5-maculatus or the Five-spotted Sphinx, Hubner some years afterwards giving it the name Celeus. I suppose it to have been through an oversight that authors generally have copied the original name from Mr. Haworth in its masculine form, which is evi. dently an inaccuracy. Mr. Clemens in his Synopsis of North American Sphingidæ, (Journal Acad. Natural Sciences, new series, vol. IV, p. 166,) cites Dr. Harris as describing the Carolina in his Catalogue of North American Sphinges (Silliman's Journal, vol. XXXVI, p. 294), whereas it is clearly the 5-maculata which is there described under the name Carolina. He also gives both these species as being distributed generally throughout the United States. But over most of New England and New York the 5-maculata is the exclusive species. I have no knowledge of the Carolina as occurring except in the southern sections of our State, where, and throughout the middle States, the two species are found associated together; whilst farther south this disappears and the Carolina alone is met with, its geographical range extending onward through Mexico and the West Indies, and into South America, probably as far as the tobacco grows.
As already remarked, the two insects are closely alike both in their larva and their perfect states. The worms are of a bright green color, their skin is wrinkled transversely and is commonly dotted over with white, and they are both marked with a row of oblique white stripes along cach side of the body; but in the southern worm there are no longitudinal white streaks meeting the lower ends of these oblique ones to form the V-like marks which we invariably sce upon our northern worm. In their perfect state, the TOBACCO-WORX. THE PARENT MOTA. HER LONG TONGUE. HER FOOD. HEB EGGS. millers of both species are of a gray color with a row of five yellow spots along each side of the body, these spots being bordered with black, and the wings are varied with brown clouds and obscurely marked with black lines, and on their undersides the hind wings are crossed by two blackish zigzag bands, which are also obscurely traced upon the forward pair. Thus they are so alike in their colors, and in so many of those spots and marks which are most conspicuous, and which the eye first notices, that you feel quite certain on looking them over, that they are both one species. It is only when you come to closely inspect some particular points that you detect such discrepancies as assure you they really are different insects. The plainest mark of distinction between them is the black bands which cross the upperside of their hind wings. In the moth of our northern Tobaccoworm you see two zigzag bands on the middle of the wings, the same as on the underside. But in the southern you observe in place of these a single broad band, which is very slightly if at all toothed or jagged along its sides. In addition to this, on the hind body of the former, you notice a slender black stripe along the midille of the back, of which there are no vestiges in the latter. These marks will suffice to enable any one who has either cf these millers under his eye, to decide which species of the two it is, We will next relate the biography of our insect.
The moths do not all make their appearance simultaneously, but come out one after another, mostly in the month of July, though continuing to occur abroad until the frosts of autumn bave destroyed the flowers from which they are fed. During the day time they remain at rest, hid from view, and come out in the evening to feed and lay their eggs. From its thus appearing abroad upon the wing at the same hours when the musketos are most numerous and annoying, Drury states that the southern species has in some parts of the West Indies obtained the name of the Musketo Hawk, it being also supposed that it is attracted forth at that particular time in order to feed upon these petty torments. This, however, is a great error. The sole food of these moths is the honey of flowers, for obtaining which they are furnished with a remarkably long slender tongue, which, when not in use, is coiled up like a watch spring, and concealed between the palpi or feelers. It may be unrolled and drawn out by inserting a pin into the coil, and when fully extended is five or six inches in length. Thus it is epecially adapted for probing flowers which have long slender tubes, such as the tobacco, stramonium, petunia, &c., whose nectaries are beyond the reach of bees and other honey-gathering insects. The moth resembles a humming bird in its motions, and also in the sound made by its wings as it is hovering around flowers and sipping the honey from them. The tongue is fully extended at such times; and hereby the moth is poised on its wings at a distance of some inches from the flower on which it is nourishing itself.
Its eggs are probably placed on the underside of the leaves of those planta on which its young feeds. The worms which come from these eggs are voracious feeders, consuming a large quantity of foliage and growing rapidly, whereby some of the earliest ones attain their full size by the end of July; but it is during the month of August that they are present upon
ich freque plant. Theseand the woring
TOBACCO-WORY. ITS HABITS. THE PUPA. DEPTH OF ITS INTERMENT. the plants in the greatest numbers. They move about but little during the daytime, and being of the same green color as the stalks and leaves, they are difficult to discover. Usually, the presence of one of these worms upon our tomatoes is first indicated to us by the large black pellets of excrement which it drops, some of which frequently lodge in the forks of the stalks or adhere to the glutinons hairs of the plant. These pellets are of a short cylindrical forn, and deeply grooved lengthwise; and the worm, as if to guard against its presence being betrayed hereby, when it is crawling along the stalks, if it chances to come to one of these pellets, it pauses and takes it up in its jaws and drops it to the ground.
When the worm is grown to its full size it leaves the plant on which it has hitherto been living, sometimes wandering away to a distance from it, ard roots down into the ground to the depth of some inches below the surface. It here becomes quiescent, and casting off its larva skin it appears in its pupa or chrysalis form. By this change it is diminished a third in its size and is now of an oval form, four times as long as thick, and covered with a hard crustaceous shell of a glossy bright chestnut color. This pupa of the tobacco-worm is particularly curious' from having its forward end prolonged on one side into a long slender limb which is bent backwards, reaching to the middle of the body, where its end touches and is firmly soldered to the surface, thus forming a kind of loop resembling the handle to a pitcher-this being the sheath in which the tongue is enclosed, which, in the perfect insect becomes developed to such a remarkable length. In this state the insect remains through the winter and spring. It is currently stated that it lies so deep in the ground as to be beyond the reach of the winter's frost, but this point requires further investigation, for frequently in harvesting potatoes this chrysalis is disinterred, lying only a few inches below the surface. Every laborer who has been much employed in digging potatoes, and every boy who has been assigned the task of picking them up, will recollect having noticed it, the curious loop or pitcher-like handle on one side, having particularly drawn his attention to it. In the garden, also, where tomatoes have been grown, I have met with it only slightly underground. The subsoil, moreover, beneath where it is loosened by the plow, is in most situations so compact and hard that it would be a very arduous labor for the worm to penetrate downward in it twelve inches or more; and for the moth, after it comes out from the pupa shell, to force itself up such a distance through this compact subsoil, would seem to be quite impossible. We know furtherinore, that the pupæ of the other lepidoptera, several of them equalling this in size, pass the winter, some in cocoons elevated above the ground, others upon the surface, others slightly under the surface, where they one and all become congealed by the winter's cold without impairing their vitality. I am therefore led to conclude that the repeated instances in which I have met with this pupa lying but a few inches within the loose surface soil were not abnormal, but that this is the depth to which it is commonly buried; and that previous accounts, which represent it as lying deep in the ground, beyond the reach of the frost, are erroneous. When the
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TOBACCO-work. NOTA DESCRIBED. ITS HEAD. ITS BODY. warmth of spring has penetrated the earth sufficiently to quicken it again into life, its internal parts continue their growth and development, until the perfect insect becomes formed within the pupa shell. This shell then cracks open and the moth withdraws itself from it, crowds its way upward through the ground, and comes forth in its perfect form.
We next proceed to describe this insect in its different states,
The Moth or perfect insect (Plate 4, fig. 1,) is densely coated over with hairs and scales, wholly hiding the surface of the body from view. Its dimensions vary in the two sexes—the body of the female being somewhat shorter and more thick than that of the male. The former usually measures two inches in length, the latter a quarter of an inch more. Its width from tip to tip of the extended wings is much the same in both sexesseldom varying but a trifle from four inches and a half.
The Head is pale gray with a brown spot upon each side forward of the eye. The eyes are large and protuberant. The palpi are large and appressed to the under side of the head, with their ends projecting forward and forming a bluntly-rounded apex to the head. The long spiral tongue is glossy, yellowish-brown, with its basal portion black on each side. The antennæ are almost half the length of tłe body, and somewhat shorter in the female than in the male. They are brown, and on the exterior side hoary gray. They are nearly straight and of a thick, clumsy appearance, increasing in thickness very slightly and gradually from the base almost to the tip, and then rapidly taper into a sharp point which is curved backward. In the males they have along the two flattened faces of their inner side a fine fringe of short hairs placed at the end of each joint.
The Thorax is gray, and in front is crossed by two curved black lines meeting at their ends, forming the outline of a crescent having its conver side forward. And on each side of the middle are two black lines parallel with each other through most of their length, extending backward and outward along the edges of the shoulder covers. The hind part of the thorax is brown, with a large black spot upon each side each of these black spots having on its fore side a roundish blue-gray spot, which is edged anteriorly with a transverse line of white or sky-blue hairs. The sides are pale gray, with a brown streak extending from the eye backward to the under side of the wing socket.
The Abdomen has the form of a cone nearly three times as long as thick. In the males it is composed of seven rings—the last ones becoming gradnally shorter, and ending in two compressed tufts of hairs, which are of a broad elliptical form, and tapering to a point at their ends. In the females the abdomen is plainly shorter and thicker, composed of but six rings—the last one larger than that which precedes it, and ending in a crown of hairs forming a short cylindrical brush. On the back it is of a gray color, with a slender black stripe along the middle, a white band at the base, and a rom of white spots along each side placed in the sutures—the opposite spots being in some instances prolonged into each other, and thus forming a white band upon each suture. Upon the sides the ground color is coal blackthis color being notched into at the sutures by the above-mentioned row of
TOBACCO-WORY. THE XOTA. ITS LEGS. PRELIMINARY REMARKS ON THE WINGS. white spots along its upper side, and more deeply along its lower side by a similar row of larger white spots; and on the middle of each of the five first rings is a large round spot of a bright ochre yellow color-the hind ones smaller. The under side is pale gray, with a row of round black spots along the middle, from three to five in number—the second one being the largest.
The Legs are gray, paler on their undersides, the feet becoming brown towards their tips, with white rings on the joints. The middle and hind shanks have a pair of spurs at their tips on the underside, and the hind ones have a second pair placed a short distance above the first. These spurs are gray, with naked brown shining thorn-like tips, one spur of each pair being longer than its mate. The feet are five-jointed, the first joint being much the longest and the following ones successively shorter, with a pair of sharp hooks at the end. On their undersides are rows of small black or brown prickles, with a crown of larger ones at the apex of each joint, and along the hind side of the forward feet and shanks is a series of much larger ones.
Preliminary to our description of the wings of this moth the reader should be apprised of some generalities respecting the markings of the wings in the insects cf this order. In the immensely numerous group which in common language we designate as millers or moths, and which are scientifically termed the Crepuscular and Nocturnal Lepidoptera, an almost endless diversity in the spots and marks upon the fore wings is met with. Upon looking them over, one after another, no one will suspect there is any system, any uniformity, to these spots and marks, except it may be here and there among the individuals of a particular genus or tribe. And yet, when we come to inspect them more particularly, we shall discover that the same general designs are repeated, the same pattern is copied, more or less completely and distinctly, all through this vast series of objects, it being variations only in the minor details of the figures, as to their particular form, size, colors and distinctness, that make up the wonderful diversity which exists. These markings, which are common to the wings of such numbers of these moths, are situated and designated as follows: First, between the centre of the wing and its outer margin we observe sometimes one but more commonly two small spots of a peculiar aspect. These are called the stigmas or stigmata, this name, stigma, having been anciently given to a mark burned with a hot iron upon the foreheads of slaves who had been convicted of theft or other crime. Second, extending across the middle of the wing and between the two stigmas is frequently a darker cloudiness, which has been termed the median shade. Finally, the wing is also crossed by three bands, bars or strigæ, as they are differently termed by different writers; first, the anterior, extra-basal or sub-basal, which is placed immediately forward of the anterior stigma; second, the post-medial or elbowed band, immediately back of the posterior stigma; and third, the sub-terminal, sub-apical or penultimate, which is usually more slender and distinct than either of the others and is parallel with and a short space forward of the hind mar. gin. In the moth which is now before us the spots and marks upon the