THE AMERICAN BLIGHT BUG. (WRITTEN FOR THE "DAILY SOUTHERN CROSS.")

Daily Southern Cross, Volume XXII, Issue 2675, 12 February 1866, Page 5

THE AMERICAN BLIGHT BUG. (WRITTEN FOR THE "DAILY SOUTHERN CROSS.")

Aphis (eriosomo mali). This is one of the most remarkable and mischievous species of the whole of the aphis family. It infests the apple tree, and frequently reduces whole orchards, that were in full bearing, to sterility. Although ib is of comparatively small size, yet its capabilities of production are so great, that whole districts are covered with them in a very short time ; they are viviparous in spring, and oviparous in autumn ; it is calculated that each female produces about 25 young per day, and that one aphis may be the progenitor, during its life, of the enormous number of 5,904,900,600 individuals. Well may the farmer diead their appearance in his district. Naturally they are of a pitch brown colour, but soon envelopes itself in a white silky down on the branches of all infested trees, and as the season advances this mauviness increases and becomes white, and towards the end of the summer it looks i like a vestment of thick down upon the undersides of the infested branches ; and, on oloseexamination, a multitude of small wingless insects of the American blight bug will be found to be enclosed in this downy substance, and to be feeding beneath it, on both the bark and the juice of the tree. The Alburnum, or sapwood, being wounded by them, this at once lises up in excrescences and modes, and by this means the branches are deprived of their proper nourishment, therefore they soon become sickly, lose their leaves, and eventually perish. Branch after branch is assailed, and becomes leafless and dies ; and finally, both stem and roots, being deprived of all connection with the living leaf, soon decay, as they are beyond the reach of remedy. Many methods for destroying this blight has been proposed and tested, but all have been found to be ineffectual ; no radical cure has been found. The best remedies have only temporarily checked the disease, and extended the life of the tree foravery short period; the disease has reappeared, and, in spite of ail efforts made to save the tree, it has finally succumbed to the disease. Much speculation has existed as to what may be the cause of the apple being so very susceptible to the blight ; many ideas have been at different times advanced, but I consider that the primary cause has not yet been hinted at ; all that have been advanced are only auxiliaries, and not the real cause. Whenever the aphi« makes its appearance in any district, the only effectual way to get rid of it, is to at once destroy every apple tree in the district, aud then commence to raise new trees on a new plan, which will defy the aphis to destroy them. I think I hear some of your readers say, that that will be a hopeless ease. I would say to sueh — bide a bit ; do not be so hasty in your conclusions ; I will endeavour to show you, both by precept and example, how we may preserve apple orchards in this province that shall nob be inferior to that of any other country, not even the celebrated orchards of Herefordshire. The apple (Pyt'us Ifalus, L.) is one of the most valuable fruit trees that we possess, and was in all probability one of the earliest cultivated by man for the sake of its fruit. Homer speaks of it as being one that was cultivated in all the best gardens of his time. It was introduced into Britain at a very early period, most likely by the Romans. The cultivation of this tree is of great importance to the farmer and others, both from the great quantity of superior fruit that it produces, and from the length of time it lives and bears fruit. Halles mentions trees in Herefordshire that had attained a thousand years, and were then highly prolific. But Knight considers 200 years as the ordinary duration of a healthy tree grafted on the crab stock. In Herefordshire'great attention has always been "paid to the cultivation of the apple tree ; both the apple and the cider of Herefordshire and the adjoining counties has acquired the highest degree of excellency. To the county of Hereford its growth is of great commercial importance. The average crop is about 540 bushels per acre ; this would make about 20 hogsheads of cider, the price of which is from £5 to £15 per hogshead of 110 gallons. Many farmers make in a good year of fruit. lOOOgallons. Therearein thecounty 550,400 acres of land, and if we take one fifth to be planted with apple, there would be about 110, 000 hogsheads produced every year. Although we may not want the apple to make cider from, yet its production of fruit will be of great value to us, both for domestic use and to export to our neighbours who cannot produce them. There is no reason why we may not have orchards in this province, that will in all points equal those of Hereford. Our climate is quite as iavouraDie to its growtn, and so is our son. All we want is to adopt the same mode of culture, and take the same steps to prevent disease ; then I feel assured that we shall have as good results as they have at home. The apple tree has been introduced into this island about 50 years. It throve well for a long time, but at last the blight made its appearance, and at the pre■ent time all or nearly all of our trees have been destroyed ; what are left ar<> in a sickly and debilitated state. Many reasons have been given to try to prove what has been the true cause — numerous remedies have been prescribed ; but as yet neither cause nor proper remedy has been satisfactorily pointed out. The apple tree, when first imported from home, arrived in a healthy and vigorous state. Planted without care in ground, and nob properly prepared, and little attention paid to its culture, it soon began to degenerate. Being propagated from pips, and sownfromitsowu stalk, al«o caused it soon to degenerate. Once decay commenced, then every scion taken from such trees for.the purpose of propagation, would carry its own debility along with it, and thus disease, acquired, in the first place by neglect, would be propagated with great rapidity. The same results are to be found in the animal world. If the stock breeder were to breed in and in indiscriminately for 50 years, his stock, although at first the best the country could produce would by the end of that period be nearly useless ; or if the farmer were to plant potatoes orwheatfromthesameseedonthe same land he would realizethesamere suits. So in the apple tree. This is according to the well-known laws of vegetable physiology, for instead of the sap containing a large portion of •trong acid, in its sat), as is the case when the apple i* grafted on the wild crab-stock, it contains in its stead, an insipid juice, partly saccharine, and therefore becomes an easy prey to the aphis, which at once preys on the sapwood. It will be remembered the sap of the tree has a motion in the vessels, and rises from the roots in the tubes or vessels through the alburnum. It then circulates in the leaves, when it becomes considerably changed in its composition ; it then enters the vessels of the liber or inner bark, enabling it to produce a new layer of wood, and to perform the peculiar secretions which belongs to it; but as soon as the tree is infested by the aphis the sap wood is wounded, the vessels are cut, and the sap is prevented from ascending. The consequence is that all nourishment from the earth is excluded, and the tree dies. This is the real cause of the disease, and is past all remedy ; foralthough it might be possible to remove the blight from the stock of the tree, and thus to retard their progress, yet an inexhaustible supply of aphis will be sent forth from the roots of the tree, which is their grand abode, so that it will be labour in vain to continue the present system. The only way that T could propose, would be to take some healthy grafts from each kind of pood apple that we have got, scrubthemwellwithsoapand water, then get a good supply of stocks from some of the beat sorts of the crab tree. This belongs to the pomeus division of the Sosaceus order, and are all very nearly alied to the apple, from which it only differs in the fruit, containing a veritable number of atones All these bear a fruit resembling the apple in all essential circumstances, that is to say, a pome, not a berry ; the seeds are not mixed with the pulp, bnt in cells containing one or two seeds in each. Of these are the quince, the medlar, the service tree, the mountain ash and all the different varieties of hawthorn. On any of these the apple can be grafted without hesitation, and would make good stocks for dwarf trers ; the blight will not infest the roots of these. But to have good orchards we must procure the seed of the wild crab of the English swoods. From this, and from this alone, can we look for a lasting remedy. By the using of this stock to graft, the apple in Herefordshire has been kept free from the blight. The large quantity of acid contained in the root of the crab is death to the aphis, and at the same time it gives health and vigour to the tree, and gives a much richer flavour to the fruit. I think that I have pointed out clearly the cause of the disease, also its remedy ; what I would suggest is to use the quince and the whitethorn to preserve our sorts of apples, until we can procure the crab. There are three sorts of quinces— one bears a fruit apple shaped, andits leaf is like the apple leaf in •hape ; the second is one whose leaf and fruit is shaped like the pear ; and the third the Portugal quince, also resembles the pear. The first is th« right one to graft the apple on. I herewith enclose a leaf of each, numbered on the underside so that there can be no mistake which to use. J. P.

In a paper read at the Franklin Institute, Phila delpbia, by Mr. Albert Leeds, on the geography and geology of petroleum, he combats the opinion that the flow from the oil-wells will eventually cease, and gives a statement of his reasons, based upon facts, for the statement that henceforth petroleum deserves to be ranked with coal and iron as a solid mining interest. He refers to the evidence we possess inspecting the character of bituminous deposits all over the globe.