Rensselaer Union, Volume 7, Number 40, Rensselaer, Jasper County, 24 June 1875 — Apple-Tree Vermin. [ARTICLE]

Apple-Tree Vermin.

[From the Forthcoming Report of the Michigan State soard of Agricnltare.j OLD APPLE-TREE BORER. This pest, which has been so long in our country, is widely distributed in our State. Very lew if any orchards are exempt from its attacks. Not that it always, or generally, totally destroys the trees; still, those suffering from its attacks are always lessened in vitality, and it not infrequently happens that the trunks become so riddled with their tunnels that the tree becomes a prey to the hard winds which are sure to come with each returning year. The beautiful brown beetle, with its two Btripes of white, appears early in June, and thence on through July. So the egg-laying is principally done in these two months. The grub, whitish with a round black head, eats through the •bark, and then usually passes in and up, frequently eating through the branches far out toward the extremity. I have frequently found apple-tree limbs no larger than my thumb with a tunnel as large as a pipe-stem. These larvae push their sawdust-like particles back of them and out of the hole where they first entered, so that it is not difficult to find them. They live and feed on’ the wood of the tree for three years; hence we see how that a single larva may bore, if left undisturbed, for a distance of several feet. They finally bore a hole few exit, fill it slightly with their sawdust, and a little back of the same make a cocoon of their own chips, in which they pupate. Soon after, in June and July, the beetles again appear. Soapy mixtures are found to be obnoxious to these beetles, so that in their egg-laying they are found to avoid trees to which such an application has been made. Thus we may hope to escape all danger by washing the smooth trunks of our trees early in June and again early in J uly with soft soap or a very strong solution of the same. T. T. Lyon, now of South Haven, whose judgment is very reliable in such matters, urges that we always use the soap itself. “ We should always examine the trees carefully in September, and wherever we find this pernicious grub’s sawdust shingle out we should give him a call. Perhaps we may reach him with a wire thrust into the hole, and by a vigorous ramming crush the culprit. If we have doubts as to the crushing we should follow him with the knife; but in cutting out the borers too great care cannot be. taken to wound the tree just as little as possible. This heroic method is sure and requires very little time, and no person who takes pride in his orchard or looks to it as a source of profit can afford to neglect this September examination nor tne previous application of soap to which it is supplementary.

FLAT-HEADED BORER. At present this borer is quite as ruinous in our State as the preceding one, and I should not think it strange if in a well-balance'd account it was found even to surpass the other in the evil which it works to our fruit interests. I have seen young orchards nearly ruined the first summer after setting' by this devastator. Not long since a nurseryman came from a distant part of the State to consult me as to the ravages of this pest. He said that during the past summer, in some regions of the State, more than half the trees he sold were killed by this scourge, and of course lie was unjustly blamed. At present no nurseryman should sell trees without throwing in advice in regard to practicing against this devastator, for, as we shall see, such trees are peculiarly liable to attack. These borers are not confined to the apple tree, as I have found them working in oak, maple, and other trees of our forests.

This brownish beetle with a coppery luster is found from May till August, though I have found them more common in June and July. As with the striped Saperda-, the eggs are laid on the bark. The whitish grubs, with their enormous front, brown head, and curled tail, usually bore only superficially, eating the inner bark and sap-wood; yet I have seen, and have now on exhibition here at the college, sections of young trees over an inch in diameter bored completely through by these big-headed rascals. They eat but a single season, pupate as in the preceding case, and come forth as imagoß early in the spring.

— Q J They usually work on the trunk, though sometimes in the branches, almost always on the south, the west, or the southwest sides of the tree; and their whereabouts may always be ascertained, not only by the sawdust, but also, and more certainly by the black color of the bark. When the black color offers the suggestion of the presence of this borer we can quickly become assured by striking a knife into the same. If the blade pierces the bark and goes on still a little further we may be sure of the enemy’s presence. This borer is far more liable to attack feeble trees. Anything therefore which serves to diminish the vitality of the trees promotes the ravages of this borer. Hence, after such a winter as we have just experienced, or after having Hie 1 ’ growth of our trees interrupted by the removal from the nursery to our orchards, we are in special danger of hafm from these destructive borers. Hence, the coming season, when loss will be inevitable, we should more than ever be on the alert to mitigate the damage by our vigilance and care and by the timely application of remedies.

The remedies for the flat-headed borer are the same as those given for the ojd borer, soap in June or July, and a knife in September; though these grubs may be found in July and August, and to delay the cutting out till September would often be fatal, especially to trees in newlyset orchards. I have known cases where labor of this kind in July would have paid more than SIOO a day, besides saving a great amount of vexation.

APPLE-TREE BARK LOUSE. This is an old enemy, but though less destructive than formerly, probably because of parasites and mites which prey upon it, so that, like the Hessian fly, wheat midge, and many other insects, it has probkbly done its worst work,to leave it to itself at the present time would be to yield the strife prematurely. The bark-colored, oblong scales, so harmless in appearance, serve from August to May only for protection to the sixty or seventy wee white eggs which are found underneath. About the first of June the young lice appear—so small that, though clad in yellow, they can hardly be seen without & glass. Coming forth from under the scale they roam abont for a few days; are sometimes blown to other trees, thus spreading their evil work; but very soon settle down to earnest business. This consists in inserting their liny beaks and sucking the vitality from the trees. Very soon a scale commences to form around them, from an exudation, which is a secretion from tbe general surface. By August the impervious scale Is complete. The

eggs are then soon deposited and the parent louse dries up and shrinks awav to nothingness. 3 As the scale is impervious to most fluids, thpugh oils will penetrate it and destroy the eggs, the best time to fight these insects is just after the eggs hatch At this time soft-soap or strong soapsuds are sure death to the young lice Hence the trees should be washed the first week of June with soft-soap, not only making the application to the trunk, but also to the main branches and limbs as far as possible. We thus see tjiat an application of soft-soap to our apple trees, made the first week of June, is of exceeding value. It not only exterminates the sappers (bark lice), but banishes the miners (borers). We thus understand why our fruit trees which are thus treated seem fairly to laugh, as it' grateful for such timely aid in banishing their enemies. I have no hesitation in affirming that the apple-grower will find the above one of the most paying operations that he can undertake in his orchard. Let all, then, scrape their trees early in spring, apply soft-soap—not lye—the first of June, and again the first of July, not forgetting to adjust cloth bands by the last of June.— A. J. Cook , Professor in Michigan Stale Agricultural College.