« ՆախորդըՇարունակել »
Hand-picking is more than usually easy of adoption, to be practiced in the same manner as with the canker worms: give the bush a slight tap, when the larvæ will drop, and remain suspended by a thread for some time. By using a stick these can be drawn out together and easily crushed.
It is more than likely that this pest, which has been long destructive east, will continue to be more and more so with us as our forests are cut away, removing its native foliage. Let us all give it battle from the
Agrotis Cochrani. Riley.
Were the climbing cut-worms as destructive in all sections of our State as they are along our eastern and western shores, these insects would rank next to the Codling Moth as a pest of the orchardist, and even now it occupies no inferior position. It would be difficult to estimate the amount of damage which these insects have perpetrated in our State. They not only strip the buds from our fruit trees, but the various vines also minister to their appetites.
Little need be said on this subject farther than what has been said in reference to field cut-worms, as the characters of the various cut-worms are very similar, as also their habits; yet, just before the larvæ matures, the climbing species exhibit a strange peculiarity, as during the warm summer nights they come forth from their earthen retreats, not to nip the tender corn or tomato plant, but to climb some apple, pear, or peach tree, or some grape vine, and eat out the tender buds, thus frequently doing irreparable damage. The owner sees the damage, but not the enemy, and all ignorant of the true cause, says hard things of his bird friends. These have wrought great injury at Monroe the past season, yet hardly a sufferer knew the cause of the mischief. These larvæ hide by day just beneath the ground, where they may be found by a little digging. They may also be seen by climbing into the trees by night or by shaking the same, when the "worms" will fall to the earth. There are two or three species in our State that I am sure have this climbing habit; there may be several.
In addition to the process of digging out by hand, recommended to destroy field cut-worms, and placing armfulls of fresh clover to entrap the larvæ, as already suggested to the gardener, there are still other methods to fight or ward off the climbing species. They can be caught by using the sheet and mallet at night, as in fighting the curculio when they are in the tree. They may also be kept from gaining access to the tree or vines at all. To protect vines Prof. Tracy recommends using stiff smooth paper, about four inches wide. He winds this about the trunk, gathering in at the top, and tying about this gathered portion with a cord, drawing it tightly. The lower portion is permitted to stand out a little from the tree, so the whole resembles an inverted funnel. For larger trees, and indeed for small trees and vines, the same is
often used, but tin bands will be most desirable. The tin should be thin and bright, and should be cut into strips about three inches wide, and of a length to correspond to the size of the trees to be protected. When these are drawn closely about the tree they should lap sufficiently to be tacked or nailed through the lap: a hole should be made through one end of the tins with a punch, then in placing the tins on the tree the end with the hole should lap over the other end, and if a lath nail is used this may be made by a smart blow to pass through the other end, and into the tree. The nail should only be driven partially in so as to be easily pulled out when the tins are to be laid away. By making a narrow slit in the other end of the tin to correspond with the hole when the tin is lapped, it can be fastened by a common carpet tack, in which case the tack should only be driven partially in to the tree. Prof. Tracy recommends that the tin be tacked or nailed near the upper edge. This tin is a sure preventive, for the cut-worm cannot pass over the surface of smooth tin. Judge Ramsdell would have the tins longer, and fasten by hooking, as the ends are bent for that purpose. He thinks there is little danger of the larva passing between the band and tree. He uses these same bands in fighting the peach borer, as already described.
As these pests work far worse on sandy land, those having orchards on light soil will have to be specially vigilant.
Had this remedy been known and practiced, how much would have been saved to our State! Now that it is known, shall we not all practice, and stop this leak in our treasury?
THE ROSE CHAFER.
Macrodactylus subspinosa, Fabr. Family, Scarabeida. Sub-Order, Coleoptera.
As this old pest of the rose is becoming quite destructive to the grape in various sections of our State, it demands a brief notice.
Its history and habits closely resemble those of its family relation, the May beetle, already described. FIG. 41.
The beetles (Fig. 41) appear in June and July; eat most ravenously, seeming to relish rose leaves, grape leaves, and even cherry leaves. After this wedding feast is over, the females lay their eggs in the ground. The grubs feed on the roots of plants, but are not sufficiently destructive to attract attention. The pupa may be found in May, and in June the beetles come forth again to their work of plunder.
As this beetle will, like the curculio and blister beetles, fall from the plants whenever disturbed, they may be shaken on to sheets placed under the vines, and destroyed.
I presume that white hellebore might destroy these beetles, and there is hardly any doubt but that they would succumb to Paris green, which I think would be perfectly safe when applied so early in the season. As we have none of these beetles here, I can not experiment with these various remedies. Let some of our fruit men along the lake shore try these applications, as also that of a solution of carbolic acid, not strong enough to injure the vines, and report the results.
Erythroneura vitis, Harr. Family, Cicadellina. Sub-Order, Hemiptera.
These sprightly little insects are quite generally distributed through our State, and though they are specially ruinous some seasons, yet perhaps the very next they are not to be met at all. I think Mr. Bidwell of South Haven has discovered the cause of this sudden disappearance, and in it a method to successfully fight them.
These beautiful little insects (Fig. 42), so gaily robed in yellow, black, and scarlet, hybernate during the winter in the mature state, and may be found in fall and winter just under the vines, protected from the fatal damp by the leaves. In the spring the survivors come forth, lay their eggs on the plants, and soon die. The young are quite like the parents, except in size and absence of wings. They possess the same hopping propensity, and hence the lively
appearance whenever the vines are disturbed. The insects continue to grow, become possessed of wings, and if very abundant will well nigh suck the vitality all out of the vines.
Mr. Bidwell discovered, in collecting these hoppers one winter, that those which were under damp leaves were dead, and only those which were protected from the damp of winter survived. Hence the only practical remedy I have ever heard of for these pests of our vineyards: As soon as they have become dormant in winter, so rake up the leaves under the vines as to cause the insects to become a prey to this inability to endure wet or damp. I think it would be well to rake up the leaves in autumn and burn them, doing it on cold days, when the hoppers are dormant, and before the vines are laid down for winter.
THE GRAPE PHYLLOXERA.
Phylloxera vastatrix, Plan. Family, Aphidae. Sub-order, Hemiptera.
This little insect, hardly large enough to attract the attention of any but the cautious observer, is without doubt an American insect. Yet, from the comparative immunity of most of the grapes grown here from its blighting attacks, and ignorance of its natural history, only a part of such history being known, it was not dreamed, when Prof. Planchon announced, in 1868, that the cause of the terrible Phylloxera plague of France was a minute plant louse, that the insect was identical with that described as Phylloxera vitifolia by Dr. Fitch, twelve years before. At last the assurance seems to be conclusive that the insects are identical, though some still believe otherwise, yet with no sufficient reason, I think, and that we have suffered more or less during all our grape-growing history from the ravages of this insect, whose late importation is striking far more serious blows at this important interest in Europe.
The dull orange colored louse described by Dr. Fitch, which by puncturing the leaves causes them to become covered with excrescences or small galls (Fig. 1 FIG. 43..
43) which greatly deform the leaf, are but one form of this insect, and that by far the most harmless.
Under these galls the eggs (Fig. 44, d) are laid to the number of three or four hundred. These soon hatch, and the young lice (Fig 44, a, b) go merrily forth in their bright yellow garb, and repeat the work of their parents. Thus on, for four or five generations, all the lice are wingless, all females,-in fact, no other ever appear in the galls. What is very curious, only a few varieties suffer from these not very serious leaf galls, the Clinton seeming to be most susceptible to such attacks. As fall approaches the galls become deserted, and the
Under side of leaf, showing galls.
young descend to the roots, where they hibernate. As these gall lice will readily take to the roots and flourish if removed to those vines where the galls are never found, it is not improbable that some lice pass from leaves to roots during the summer. Why some of the lice pass to the leaɣes of certain varieties of grapes in the summer is yet unknown. It may be possible that they prefer roots when they are suitable, and will only attack leaves when the roots are not to their taste, which may be true of the Clinton. This is certainly a reasonable conjecture, if the edible character of the grape is any index to that of the root. Unfortunately there is another form of this louse,-the root form, for it is this form which has given to the future of grape growing in Europe its uncertainty. The young (Fig. 45, b) of this form are not distinguishable from those of the galls. Not so with the more mature forms (Fig. 45, e, f, g), which are not smooth, like those formed in the galls, but are covered with warts. Some of these assume a greenish cast, become large before and taper back, and, like the gall-forms, are always without wings. The others are always bright yellow, always of the oval form of the young, and finally develop stubs of wings (Fig. 47, e, f), and at last come forth with well-developed wings (Fig. 47, g, h), well equipped to go forth to new fields for conquest. They come forth from the earth as pupa, and then cast their skin for the last
and b, larvæ as seen from below and above; c, egg; d, gall; e enlarged tendrils; f, g, and h, imago gall, louse from side, above, and below; i, antenna; j tarsus-side marks show
time. These winged forms are still yellow, but have lost their tubercles. The winged forms are most abundant in August and SeptemOber, though they may be seen from July till fall. The most of these are long, lay eggs, and are certainly females. Others are shorter of body, and are supposed by some to be males, but are probably abortive females. These lay eggs from which come the true male (Fig. 46) and female, which latter lays but a single egg. These all die off in fall, so that the insects pass the winter either as eggs or as larvæ. This polymorphism, or different
a, diseased roots; b, larva louse; c, antennae; d, leg; e, f, and g, imago root lice; h, granulations on the skin; i. forms of the same species, is not
peculiar to lice, but is shown in even the highest insects, as seen in the bees and ants. FIG. 46.
As already intimated, some entomologists deny the identity of these forms, especially the gall and root form. Now, as it is not exceptional among insects, and as Prof. Riley, who has done himself great credit by his thorough and skillful investigations of this insect, has produced the gall form from the young of the root form, and vice versa, it seems to me that doubt should be entirely banished. Besides, any vineyard, so far as I have examined, which has in it both Clinton and Catawba grape vines, will have both these forms if either.
The roots which are attacked by these lice, swell, become deformed (Fig. 47, d), and in three or four years rot. The first season the vines above ground show no signs of the evil; the second they become yellow and sickly, and frequently, die the third season.
HOW THE INSECTS SPREAD.
The wingless root forms pass from the roots of one vine to those of another and thus spread the disease. Very likely the young from the galls are blown from one vine to another, as we know the young of the oyster-shell bark-lice are. The winged females may fly, by aid of the wind, to an indefinite distance, and as a single female may become the parent of millions of lice in a single season, we can easily see why all Europe is in alarm.
VARIETIES OF GRAPES SUSCEPTIBLE TO THE ROOT FORM.
Of the grapes grown and recommended for cultivation in this State, fortunately very few are subject to serious harm from the root form of the Phylloxera, the only form that does serious damage. The vigorous, rapid-growing varieties are almost exempt, while the slow growers are very apt to suffer. The Concord, Hartford Prolific, and Israella are almost entirely exempt, as is the