Evening Republican, Volume 20, Number 249, Rensselaer, Jasper County, 17 October 1916 — LEAF BLISTER MITE [ARTICLE]

LEAF BLISTER MITE

Minute Animal Which Attache the Follags of Pear and Apple Red or green blister like spots appearing In the early spring on the foliage of the apple and pear are usually due to the leaf blister mite. This is not an insect but a small animal. Invisible to the unaided eye, whibh attacks standard varieties of pear and apple trees and often Inflicts serious damage. Where trees are seriously infested, the premature fait of both fruit and leaves may.result In such cases n special application of lime sulphur wash or other spray may be necessary. Ordinarhy, however, the regular orchard spraying is sufficient to control the mite. Badly infested branches of the pear trees may be cut off ari burned. Care should be taken not to confuse the work of the mite with the leaf spot disease or the results of heavy spraying.

Describing the leaf blister mite, showing how it may be recognized, and giving methods of its control, the department has issued a new Farmerr Bulletin No. 722, “The Leal Blister Mite of Pear and Apple,” by A. L Quaintance. The leaf blister mite passes the winter beneath the bud scales. There it waits for the opening of the buds and attacks the young leaves as soon as they push out in the spring. The liny animals bore small holes from the under side of the leaves into the interior, where they lay their eggs. This causes-the small, pimple like galls on the upper surface of the leaves. The spots later increase in size, sometimes to one eighth of an inch, and on the pear tree are red and often brilliantly colored as they grow. In the case of the apple the eruptions lack the mor&-brilliant, coloring and are found m orfi-_along—the—margin - of the leaf. In both cases the spots final lj turn brown or black, and if the pest !s abundant the leaves become ruptured and wrinkled. More than 250 varieties of apples are attacked by the mite, injury being especially severe on some well known commercial sorts, such as the Ben Davis, the King, Baldwin, Rhode Island Greening, and the Williams favorite. Where orchards are seriously in fested as has been noted in New York State, lime sulphur washes give excellent results. They avoid the injuiious effects upon fruit buds which sometimes results from the use of oil sprays. The wash should be applied thoroughly, coating the twigs and brandies. ■■ - A standard solution of kerosene emulsion may also be used. The stock solution should be diluted with five parts of water for spraying purposes. One application should be given in the late fall, as soon as most of the leaves have fallen, and another in the following .spring, before the trees put out foliage. If it is possible to give only one treatment, the sprays should be used in the fall. At this time many of the mites have not yet gone to the bud scales, but,occur in the down covering the young wood ,and hence aremore ~easily killed;