The Red Spider is a small eight-legged mite which receives its name from its color (always of a rusty red). It has the spider habit of spinning a fine web, generally on the under side of the leaves of trees. It is so small that it is almost invisible to the naked eye.
When Red Spiders establish themselves on a plant, they spin webs of very fine texture on the under side of the leaves. Then by means of their suckers they bore into the leaves and suck out the juice or sap. The leaf becomes yellow and covered with spots, ultimately dies and drops prematurely. Sometimes an attack of this pest strips the tree months before the usual time; if a fruit tree, the crop for the year fails, and besides, the branches formed for the following year are stunted and immature.
The Red Spider seldom attacks plants in a good healthy condition, unless they suffer from drought. Hence any measures which encourage vigorous growth, such as plenty of water at the roots, frequent hosing overhead, mulching the ground around the plants with manure and freely cultivating the soil, diminish the effects of the attack to a great extent.
When a plant is attacked by Red Spiders, equal parts of sul-phur and coal-soot should be mixed and dusted freely over the entire plant, or one pound of sulphur-dust with two pounds of soot should be put into six gallons of water and syringed over the plant attacked. If this pest gets into a green-house, the hot water pipe should be painted with a paste made of sulphur and quicklime in equal parts, If the green-house is heated, the leaves should be dusted with sulphur and soot as recommended for out of door plants, while the atmosphere of the green-house should be kept in a moist condition, and, if these suggestions are followed and careful attention is given to the watering of the roots, the Red Spider will not make much headway.
Caterpillars are of various kinds, some species attacking only Oaks, while others confine their operations to the leaves of the Rose, and still others are found only on the Hawthorn or Cabbage, etc. Those which live in webs, such as the common Oak tree caterpillar, can easily be cut off and destroyed by waiting until evening when they invariably return home after feeding on the Oak leaves all day. The branch on which they have woven their webby home should be cut off, and the caterpillars can then be crushed or piled up and set fire to. In the case of those whose nests are too high to be reached by hand, the branch can be cut with long-handled shears and the caterpillars can be destroyed as just suggested, or, if preferred, an oiled rag can be tied to a long pole and lit, and the web of the nest of caterpillars touched with the lighted rag, their home thus being destroyed and the whole colony killed. No attempt should be made to destroy them in the middle of the day, as they are at that time feeding all over the tree, and any which are overlooked will immediately commence building a new nest, and consequently multiply the number of nests to be destroyed.
The common Rose caterpillar is easily got rid of by hand-picking or by dusting with Paris green.
Slugs are about the commonest pest, and these destructive nuisances are well known to all garden owners. They seem partial to soft-wooded plants of low growth, hiding under the leaves which touch the ground, and feeding on the undergrowth and flower stalks, seeming to take delight in eating holes into or pieces out of the leaves and flower-stems, thus ruining many promising flower-beds.
Among the most effective remedies are baits of cabbage and lettuce leaves laid near the plants which need protection. These traps should be set in the evening and examined the next morning; the slugs should be shaken off and covered with lime, salt or wood ashes. All of these applications should be repeated at least once, as the slugs seem to have strength enough to crawl off with one coat of the dust and to throw it off with a coat of slime, but the second application invariably kills them. Frequent dusting of the ground immediately around where the plants are troubled has a great tendency to drive off the slugs. A little dusting of lime close to the neck of favorite plants is also a good cure and a better preventive. A dressing of soot is a very good fertilizer and a good protection against all the varieties of slugs and snails.
The Scale insects are among the most dangerous and troublesome of injurious insects, a single female raising from two hundred to five hundred at a single brood. They are said to hatch four or five generations a year. For the clearing of nursery stock, hydrocyanic acid gas is frequently used by fumigating, but, as it is necessary to have the use of a tent in doing this, it is not always convenient for the amateur, and, unless the operation is very carefully carried out, damage to the plant may result.
A favorite remedy for the common black or brown scale is a strong mixture of tobacco and whale-oil soap, the soap suffocating them by closing the breathing pores along the sides of their bodies.
Use about one-quarter pound of the soap and two ounces of extract of tobacco to a gallon of water and syringe the plants about three times a week, syringing with clear water the day following the application of the mixture; continue the spraying until all of the scale are washed off.
Canary Islands Date-palm.