Figure 14, b, b, b, gives a view of the larva of the true Colorado potato-bug, in various positions and stages of its existence. Figure 15, b, b, of that of the bogus Colorado potato-bug. It will be seen at once that the head of the former is black, and the first joint behind the head is pale and edged with black behind only; that there is a double row of black spots along the side of the body; and that the legs are black. In the other larva, (Fig. 15, b,) on the contrary, the head is of a pale color, the first joint behind the head is tinged with dusk and edged all round with black; there is but a single row of spots along the side of the body, and the legs are pale.
Figure 14, d, d, exhibits the true Colorado potato-bug; Figure 15, the bogus Colorado potato-bug; each of its natural size. Figure 14, e, shows the left wing-case enlarged, and Figure 15, e, an enlarged leg of the latter. On a close inspection, it will be perceived that in the former (Fig. 14, e) the boundary of each dark stripe on the wing-cases toward the middle is studded with confused and irregular punctures, partly inside and partly outside the edge of the dark stripe; that it is the third and fourth dark stripes, counting from the outside, that are united behind, and that both the knees and feet are black.
In Figure 15, d, on the contrary, it is the second and third stripes—not the third and fourth—counting from the outside, that are united behind, and the leg is entirely pale, except a black spot on the middle of the front of the thigh. The eggs (Fig. 14, a, a, and Fig. 15, d, d) are yellow, and are always laid on the under side of the leaf in patches of from twenty to thirty; those of the bogus are of a lighter color. Each female of the true Colorado potato-bug lays, according to Dr. Schirmer, about seven hundred eggs. In about six days the eggs hatch into larvæ, which feed on the foliage of the potato plant about seventeen days; they then descend to the ground, where they change into pupæ at the surface of the earth. The perfect beetle appears about ten to fourteen days after the pupa is formed, begins to pair in about seven days, and on the fourteenth day begins to deposit her eggs. There are three broods of this insect every year. Neither geese, ducks, turkeys, nor barn-yard fowl will touch the larva of the Colorado potato-bug when it is offered to them, and there are numerous authentic cases on record where persons who have scalded to death quantities of these larvæ, and inhaled the fumes of their bodies, have been taken seriously ill, and even been confined to their beds for many days in consequence. It is also reported to have produced poisonous effects on several persons who handled them incautiously with naked hands. Various plans have been tried to destroy this persistent enemy of the potato plant. Powdered hellebore is said to have been used with effect as a means of destroying the pest. It should be dusted on and under the foliage when the plant is wet with dew. Hellebore, however, is a dangerous remedy on account of its poisonous qualities. A mixture of one part salt, ten parts soap, and twenty parts water, applied to every part of the plants with a syringe, is quite effectual. Several cannibal and one parasitic insect are known to prey upon the larva of the Colorado potato-bug, and the eggs in vast numbers are eaten by several species of lady-birds and their larva.
GENERAL REMARKS ON INSECTS.
The time is not far distant when the American farmer will be obliged to put forth greater efforts to destroy noxious insects than he has hitherto. It is a well-known fact that noxious insects are increasing in a rapid rate throughout every part of our land. The country is becoming so "buggy" that eternal vigilance is the price of every thing produced from the soil.
Close observers calculate that more fruits of various kinds and varieties are annually destroyed or rendered worthless by insects than are gathered and used by man. The cotton-worm, the wheat-midge, the canker-worms, the potato-bugs, are each every year increasing in numbers and destructiveness.
The "curculio" alone destroys millions of dollars' worth of fruit annually.
It is a safe estimate, all things considered, that, if noxious insects of all descriptions could at once be annihilated throughout our country, and mildews of various classes be effectually held in check, the cost of living to our people would, in-a short time, be reduced to one third of its present amount. It is disheartening to see what a vast amount of grains, fruits, and vegetables is annually eaten up by the larvæ, or appropriated by the perfect insects of various classes, merely for the sake of propagating their abominable species. Yet, in view of all the devastation, but feeble effort is made to abate the evil. Birds, many species of which nature seemingly designed on purpose to keep insects in check, are wantonly shot by lazy boys and indolent men, who range the fields and forests, killing all, from the humming-bird to the crow. Legislative enactments made expressly to protect the insectivorous songsters are every day violated with impunity. One man plants an orchard and does all he can to destroy noxious insects; another man near him also has an orchard, but his orchard serves no purpose but to propagate "curculios," "canker-worms," "bark-lice," "tent caterpillars," "codling moths," etc., for his neighbors, and, as a matter of course, the whole neighborhood swarms with noxious insects. If all cultivators would act in concert and with a will, insects might be reduced in numbers very rapidly. Most moths of night-flying insects are attracted to and destroyed by small bonfires kindled in still evenings during the summer months.
Bottles half-filled with sweetened water, hung here and there, will trap countless bugs. Strong soap-suds applied immediately after they hatch is a sure remedy for plant lice. Molasses and water, to which a little arsenic has been added, placed in shallow dishes among the vines, is good medicine for potato-bugs, and all bugs in general. A lighted lamp placed in the centre of a common milk-pan, partly filled with water, the whole elevated a few feet from the ground, will, on a still evening, attract and destroy the wheat-midge and similar insects in great numbers. The calculations of the "curculio" and "codling moth" are brought to naught by turning hogs into the orchard to eat the stung fruit as it falls, and the larva that depastures upon the leaves of the current and gooseberry is destroyed by syringing the plants with a mixture of soap, salt, and water.