This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
THIs insect is attracting much interest among western orchardists. Cultivators understand the nature and extent of its depredations, and the difficulty of ridding their trees of this pest. All are anxious to find a sure remedy of easy application. Spirited controversies are carried on over the different remedies proposed, some denouncing those which do not at once accord with their own or some long established theory. Facts are facts, in spite of regularly received orthodox . opinions; now and then new theories must be wrought out to suit these unyielding facts. The intelligent progressive orchardist, will try, with all proper caution, such remedies as seem feasible and practicable - try them thoroughly, and hold fast to those which prove good, though they conflict with preconceived notions. An interesting account of this insect was given in the November No. of the Horticulturist. From some of the statements of "R.," however, my own observations would lead to different conclusions. I have never been able to discover more than one brood in a year, which in this latitude hatches about the first of June. The scale is never found on the new growth, made after about the middle of June.
Though quite active for a short period, probably but for a day or two, I do not think this insect journeys far from the place of its birth. Being exceedingly light, it is liable to be blown to different parts of the tree, or to other trees; hence arises the idea that it "crawls all over the tree." In from one to three days it becomes stationary, where it remains, feeding upon the Bap of the growing tree, till it attains full size. Passing through its different stages, at the end of the year we find it full of life, ready to increase itself manifold. , From these few parents spring a great army of depredators, going on to increase in like ratio each succeeding season.
Neglected trees of stunted growth, and more especially those planted on wet, badly drained land, are most liable to infection from this destructive insect. The preventive will readily suggest itself; drain the land and thoroughly cultivate the soil. Where the trees are not badly affected, this treatment alone will usually rid them of these pests.
I have seen whole orchards, in which the trees seemed entirely covered with these scales. No remedy, to my knowledge, has proved so efficacious or more harmless than "Tar and Linseed oil," which I have previously recommended through different agricultural journals. Equal parts are to be mixed thoroughly by heating; when cool or just warm enough to spread, a very thin coat is to be applied with a brash to all the affected parts. An advantage of this remedy is, that it may be applied at a leisure time,.late winter or early spring, when the tree is in a state of rest; to facilitate the operation, it will be well to first thoroughly prune the tree. This composition forms a varnish, which readily cracks when the sap begins to flow and the bark to expand, admitting the air to the bark. In the course of the summer it peels off, carrying the scales - now dead - with it, and leaving a clean surface. Notwithstanding this treatment conflicts with long received opinions, trees thus treated have not only survived, but have grown - this the second season - well, and borne good crops of fruit. The wash proposed by Dr. Harris, or any strong caustic application made while the insect is yet young, will doubtless be effectual in destroying them.
The objection to the use of these remedies is, that to be of sufficient strength to kill the insect, it will also destroy the foliage, and thus seriously injure the tree; and then, too, as the insects do not all hatch out at once, more than one application is necessary, or enough are left to soon cover the tree again.
It seems to be the destiny of us poor mortals who are sent into this troublesome world to work put our own salvation, or some-thing worse, to find every blessing with which we are surrounded in the way of vegetable or animal life followed up by some destructive enemy, in the way of disease, or living creature of prey, to cut it down before we can enjoy its benefits. Were it not for the labor of counteracting these scourges, the great command, "In the sweat of thy brow shalt thou eat bread," would be shorn of half its bitterness. We are told by the naturalists who use the solar microscope, that even fleas get lousy! No wonder then that cattle, some sorts of humanity, and even our trees are thus affected. We are indebted to Mr. Hanford, and all others who can assist us in extirpating these marauders into the peace and quietude of our gardens and orchards. Thorough scraping, and soapsuds, or lye washing, with good culture, are the best methods I have tried. It is a pottering job, and I hate it, but it must be done, or the trees will suffer.