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ITS WINGS DESCRIBED. fore wings appear to have been regarded by previous writers as being so confused and obscure that they have attempted to give no full description of them. Yet we here find the same series of bands extending across the wings as are mentioned above, though portions of some of them are so modified, so faint and irregular, that they can be satisfactorily made out only in specimens which are most perfect, and by an eye that is well exercised in tracing the very obscure marks which so frequently occur upon the wings of this order of insects. · The Wings are long and narrow, the hind ones twice and the forward ones nearly thrice as long as broad. They are traversed by strong longitudinal veins, of which there are eight in number ending in the hind margin of each wing and running nearly paralled and equidistant from each other. The upper wings are gray with a large faint brown cloud occupy. ing the disk and apex. Two bands, each formed of three parallel brown or blackish lines extend across these wings, very irregularly, the one before, the other behind the middle. The anterior band we describe as follows. On the inner margin towards the base are three parallel lines, usually very distinct, running obliquely backward and outward half way across the wing to the anterior end of the brown cloud, each line being turned abruptly forward and forming an acute angular point upon the seventh one of the eight longitudinal veins. Beyond this, these lines become very obscurely traced, only one or two of them being dimly perceptible, extending along the outer side of the anterior end of the brown eloud, till they nearly reach the small stigma spot, where they again turn obliquely forward and outward, here becoming more distinct for a short distance on the inner side of the first vein, across which they are continued in three very oblique streaks to the outer margin, the anterior one ending about opposite to its commencement on the inner margin. The stigma is a very small egg-shaped spot, placed obliquely, with its smaller end towards the inner base of the wing, its center gray and no paler than the ground color around it, it being in most instances marked only by the dusky ring around its margin. The three lines forming the post-medial band commence near the middle of the inner margin, the two anterior lines running backwards parallel with the inner margin, till they reach the inner vein of the wing, between which and the next vein they cach form a mark shaped like an arrow-head, at a considerable distance apart. They then pass upon the brown cloud which occupies the central portion of the wing, where they are widened into two broad, dusky streaks, which are cloud-like and obscure, running obliquely and nearly parallel with the hind margin until they reach the fourth vein, where they abruptly turn to a transverse direction and extend onward to the margin at right angles therewith, these lines being formed of confluent arrow-head spots, which are more distinct in the anterior line, particularly at its outer end. The third line of this band extends across the wing parallel with the second one, the space between them being grayish, this color forming three or four pale cloud-like spots on the iuner side of the middle of the wing, occupying the angles formed by the arrow-heads composing this portion of the second line. Where this third line crosses the
inner vein it juts backward, forming a very acute angle, as it does also in a less degree in crossing most of the other veins. Extending across the three lines of the post-medial band, in the space between the third and fourth veins, are two very slender black lines, which are united at their ends, forming a very narrow, elongated ellipsis, its anterior end very acute and reaching almost to the stigma. And parallel with this on its inner side, in the space between the fourth and fifth veins is a similar ellipsis, which is less than half the size of the outer one. These ellipses sometimes appear merely as gray streaks, the black lines along their edges being obsolete, that along the outer edge of the outer one being most prominent and near its forward end widened into a small oval spot. Forward of the hind margin is a coal black line, the sub-terminal, the most distinct and conspicuous of all the marks upon the wings. It is waved towards its inner end, conforming to corresponding but more slight curvatures of the third line of the post-medial band, with which line it is parallel through its whole length, a narrow brown space intervening between them. It is frequently deflected forward as it crosses the fourth vein, and it here terminates in the hind end of the elongated ellipsis. Behind this line, extending along the border of the wing near its extreme edge, is a white line, the space between it and the black line. being clouded with bluish gray. Finally, upon the brown ground at the apex of the wing is an oblique coal black line, extending from the tip forward and inward to the post-medial band, where it ends between the second and third veins. Its hinder portion is margined on its outer side by a pale streak, and where it crosses the second vein it curves forward and forms an acute angle. The fringe is short and brown, alternated with small gray spots placed half way between the ends of the veins.
The under wings are blackish at their base, and have a broad, gray hind border, all their middle portion being dull white, and crossed by four black bands. The anterior band is curved, and is commonly united with the second band inside of the middle, and again at its inner end. The second and third bands are parallel or slightly recede from each other towards their outer ends, their inner ends being usually curved almost to a half circle, with the concave side facing forward, the second band being widened and often becoming double in the middle of its curvature. Through the remainder of their length these bands are zig-zag or composed of arrow heads united at their ends, which form acute points projecting backward upon each of the veins. The fourth band is broader than the others, but towards its inner end it tapers and gradually becomes slender, its outer end being curved forward. It is parallel with the hind margin, and forms a border to the gray color of the hind part of the wing. The fringe is short, and of a brown color alternated with white, and becoming wholly white at the inner angle,
On their undersides the upper wings are dull brownish gray, more clear gray along the outer border, and are crossed in their middle by two obscure dusky bands, sometimes with a third band very dimly perceptible between them. These bands, as is particulary obvious in the hind one, are [AG. TRANS.]
TOBACCO-WORY. THE WORY DESCRIBED. formed of a series of curves on the spaces between the veins, with their ends turned backward and forming angles upon the veins; and at the tips of these wings is a black oblique line, corresponding with that upon the upper side, but much more slender and simple. The hind wings are gray, with their hind border brown, and are crossed by two blackish bands, which are repetitions of the two middle bands of the upper surface, but more dim, more slender, and running back upon the veins in longer and sharper points.
The LARVA grows to the thickness of one's little finger, and is somewhat over three inches in length or three and a half inches when it is crawling, it being then more elongated than when at rest. Its surface is destitute of hairs or bristles. It is divided into thirteen segments, those at each end
Tobacco Worm. being shorter and less distinct. The surface of each segment of the body is crossed transversely by impressed lines and roundly elevated intervening spaces, giving them a ribbed appearance, there being eight of these elevated ribs to each segment. In viewing this larva the eye first of all notices a formidable looking, stout, thorn-like horn, placed at the hind end of the back, and projecting obliquely upward and backward, about as long as the segment which is next forward of it, slightly curved, and its surface rough from little projecting points. Low down upon each side is a row of large oval dots, which are the spiracles or breathing pores. The head is small
, horny and shining, of a flattened spherical form, and the mouth furnished with a pair of stout jaws. It has three pairs of small tapering feet placed anteriorly upon the breast, each having a sharp hook at its end, and four pairs of short, thick, fleshy pro-legs along the underside of the body, with two similar ones at the tip.
The color of this worm is commonly bright green marked with white. Numerous faint whitish dots are usually perceptible, at least on the forepart and underside of its body, and along each side are seven straight oblique stripes, the last one of which is prolonged more or less distinctly to the base of the curved horn. These stripes are usually margined along their upper sides by a faint dusky cloudiness; and meeting their lower ends is a longitudinal stripe, placed low down upon each segment, and forming, with the oblique stripe, a V-shaped mark, having its point directed forward, with the breathing pore placed in the angle which is thus formed. The hind most breathing pore
has a much shorter and more faint white stripe
VARIES GREATLY IX COLOR.
THE PUPA DESCRIBED.
on its upper and another on its lower side, the two stripes uniting together forward of it; and at the anterior end a faint white streak is commonly visible for a short distance forward of the lower end of the first oblique stripe. At the hind end of the body is a flattened triangular space which is margined with white upon each side. The head is green, sometimes with a vertical black streak upon each side. The anterior legs are dusky towards their tips, and on their inner sides are a few small black bristles. The soles of the pro-legs are black, as is also the curved horn at the end of the back.
This larva is liable to vary in its colors to a surprising extent. Many persons from noticing in their gardens worms which are so totally dissimilar in their colors confidently suppose there is two or three different species of them infesting their tomatoes. And the same varieties occur upon the potato, and probably also upon tobacco. Its most common color is leek green. From this it varies to lighter yellowish green, and on the other hand to various shades of darker brownish and blackish green. In other instances the green color wholly vanishes, and the worm is pale or deep amber brown, blackish brown, purplish black or pure black. In these brown and black varieties the head sometimes retains its normal green color, but is usually the same color with the body. The dots upon the skin and the oblique stripes along the sides are very often light yellow instead of white; and where the ground color of the worm is dark brown or black, these markings are always yellow, or sometimes pale pink red. The breathing pores are black, but sometimes dark red or dull yellow, and are surrounded by a ring of white or pale blue, which is usually inclosed in a second ring which is sometimes brown, sometimes black. The curved tail-like horn, so far as my observation goes, is the only part which is constant in its color, this being always black.
The Pupa or chrysalis is of an oval form, its opposite sides nearly parallel through most of its length, and tapering at each end. It is four
times as long as thick, its length being two to two and a half inches. It is of a chestnut brown color, paler in some places and blackish in others. . The
anterior end is irregularly narrowed and Tobacco-worm Pupa.
at its apex is prolonged into a remarkably long cylindrical tongue-case the thickness of a coarse knitting-needle, which projects downward and is curved backward at a distance of nearly a fourth of an inch from the surface of the breast, becoming straight through the last half of its length and reaching half the length of the body. It is thickened and bluntly rounded at its end, which slightly touches the surface of the body and is firmly soldered thereto. It is evenly ribbed transversely, appearing as though the inclosed tongue were divided into a number of short joints like the antennæ, and along its outer and its inner sides are two elevated lines extending its whole length. The wing-sheaths are smooth and glossy, with faint elevated lines marking the veins of the inclosed wings. They are firmly soldered
KILLED BY IXTERXAL PARASITES.
TABIR HABITS. to the body and reach two-thirds of its length, and interposed between them at their ends is a single pair of the leg-sheaths, which exactly equal them in length. Along their lower edges are the antennæ-sheaths, regularly marked with transverse impressed lines and tapering to a very acute point on each side of the end of the tongue-case. The rings of the body are closely and confluently punctured on their anterior sides and show numerous transverse irregular scratches and fine wrinkles towards their posterior edges. The breathing pores form a row of oval impressions along each side, each having two acutely elevated lines and between them a narrow elliptic cleft. On the back at the base of the abdomen is a smooth black transverse ridge interrupted in its middle. The three short rings at the hind end are rapidly narrowed, forming a conical point having at its tip two small thorn-like points, one larger than the other.
We come in the next place to consider the natural enemies and destroy. ers which restrain this insect from becoming excessively multiplied and namerous. Large and vigorous as this tobacco worm is, enveloped in such a tough, leathery skin, and jerking its body about with the force and spitefulness it does when anything molests it, we should scarcely suppose any other creature would care to encounter it. And yet it finds its mortal foe in a little four-winged fly, scarcely a thousandth part its size. It is truly wonderful that such a pigmy as is this fly is able to attack and destroy such an elephant as is this worm. The fly alights upon the worm, and with the short sting or ovipositor with which it is furnished pierces its skin and inserts a minute egg in the puncture. It continues to repeat this operation at one point and another upon the back and sides of the worm, until its whole stock of eggs, amounting to a handred or more, is exhausted. These eggs hatch minute maggots, which distribute themselves all through the body of the worm, feeding upon its fatty substance, but without attacking any of its vital parts. And thus the worm continues industriously to feed and elaborate nourishment for feasting and pampering these greedy parasites which are luxuriously rioting within it. If a worm which is thus infested be cut into, it appears to be everywhere filled with these little fat maggots. When they have got their growth they gnaw out through the akin, but instead of dropping to the ground and there secreting themselves as they would be expected to do, they still cling to the unfortunate worm, each maggot spinning for itself a little oval white cocoon, one end of which it fastens to the skin of the worm at the orifice where it has issued from it. Thus the worm comes to present the remarkable spectacle of being clothed, as it were, with a hundred or more of these cocoons, resembling little white seeds like kernels of rice adhering to and in places wholly corering its back and sides. I have counted one hundred and twenty-four of these cocoons upon a single worm, and a still larger number will probably be found in some instances,
These parasitic cocoons are milk white and of a regular oval form, 0.15 long and 0.06 broad. Their walls are no thicker than thin writing paper, but are very dense and firm. Their surface is minutely uneven, with a few loose, wrinkled threads at one end, whereby they are held to the skin of