Part 7

Practically all vegetable crops are subject to attack by the following insects:

Aphis, or Plant Lice.—These occur in both small and large species in a great variety of color. They injure the plants by sucking their juices, and frequently cause the leaves to become curled and deformed. Usually these insects are to be found on the soft growing tips of the plants or on the under sides of the leaves. Prompt application of remedial measures is necessary. The green-colored forms are usually the easiest to kill, and a simple soap solution is generally effective. The black aphids are more tenacious of life, and a stronger insecticide must be used, such as nicotine solution or kerosene emulsion.

Cutworms are the larvæ of several species of moths. They are especially partial to beans, cabbage, corn, onions, and tomatoes. They are usually dark-colored, greasy-looking caterpillars which spend most of their time, when they are not eating, just underneath the surface of the ground. They cut off the plants by eating through the stems. Several different measures should be in operation at the same time to rid a garden of cutworms. One of the most effective is the use of poisoned bait, but this is not advisable when live stock have access to the garden. The bait should be strewed liberally close to the plants. Shingles or thin boards may be placed on the surface of the soil. The cutworms will congregate under these and can then be killed by any means that suggests itself. Hunting for them at night, when they are feeding, with a lantern or flashlight, is another method of reducing their numbers.

Two very important soil pests are white grubs and wireworms. They attack potatoes and the roots of many garden crops. The former are large, clumsy, white grubs, the larvæ of the June beetle. Wireworms are long, slender, shining grubs, which may be of any color from light yellow to dark brown. They are the larvæ of click-beetles. It is very difficult to control these pests. Frequent, deep tilling of the soil is probably the best remedy. If chickens are allowed access to the garden plot when it is being plowed or spaded they will eat a great many of them. Wireworms may be trapped by attracting them to buried pieces of carrot or potato. These traps must be examined every morning and the insects congregated on them killed.

Following are the formulas for the various insecticides recommended.

STOMACH POISONS FOR BITING INSECTS

Lead-arsenate Solution

1 oz. lead arsenate (paste) to 1 gal. of water or ½ oz. lead arsenate (dry) to 1 gal. of water

This can also be obtained as a fine powder for dusting upon the plants. This method is less economical of material.

Paris Green

½ oz. Paris green } and } to 3 gal. of water 1½ oz. lime }

When using Paris green as a powder it is advisable to dilute it with from twenty-five to fifty times its bulk of air-slaked lime. This acts as a carrier and renders it possible to distribute the poison more economically and effectively. It is inadvisable to use these poisons, Paris green and arsenate of lead, on heading cabbages or vegetables that are shortly to be eaten, as there is some danger of poisoning the consumers.

Pyrethrum Powder

1 oz. pyrethrum to 2 gal. of water

Can also be applied as a powder. It is a good insecticide for use on vegetables that are shortly to be eaten, as there is no danger of poisoning human beings by its use. Can also be used as a contact spray.

Hellebore Powder

2 oz. hellebore to 1 gal. of water

The hellebore should first be boiled in water and then diluted to make one gallon. It is very similar in its action to pyrethrum.

CONTACT INSECTICIDES FOR SUCKING INSECTS

Soap Solution

2 oz. laundry soap to 1 gal. of water

Nicotine Solution

½ oz. 40% nicotine } and } to 3 gal. of water 1 oz. soap }

The soap is added to this solution to assist in spreading the mixture and to make it come in close contact with the insects.

Resin Fish-oil Soap

Is recommended by U. S. Department of Agriculture to be added to contact sprays and fungicides, to act as a “sticker” when they are to be used on crops with smooth leaves to which the spray will not stick.

Use two ounces to three gallons of spray mixture.

POISON BAIT FOR CUTWORMS