This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
Fumigate with tobacco preparations under cloth-covered frames placed over the plants. Cloth should be treated with linseed oil before using, to make gas-proof. In large fields, spray with "Black Leaf 40" tobacco extract, three-fourths pint to one hundred gallons of water, adding four pounds of soap.
Pale, greenish yellow caterpillar about 4/5 inch in length when mature, feeding on the foliage early in the season; later boring in the fruits.
Use arsenicals early in the season.
Tobacco extract, soap solution or fumigation.
Grayish maggots, 1/2 to 3/4 inch in length when mature, feeding in the bulb. The adult is a large hairy fly.
Examine bulbs and discard infested ones, burning them. If bulbs are placed in water for from two to eight days the maggots will usually leave them. Nasturtium. Aphis. A dark-colored plant-louse.
Spray the plants with tobacco extract or soap solution.
Use tobacco preparations for controlling these pests.
Circular greenish yellow scales with a glassy appearance. Especially destructive to golden oak.
Kerosene emulsion or soap solution. Tent Caterpillars; Tussock Moth;
Circular or oblong, reddish to dark brown scale with a central black spot.
See Pineapple. Purple Scale; Red Scale;
Whitish maggots attacking the bulbs of onions.
Same as for cabbage maggot.
Small maggot feeding on the bulb and roots; several generations.
Use lime, tobacco dust or hellebore as repellents to prevent oviposition. Some of the maggots may be killed by applying carbolic acid emulsion or hellebore decoction to the soil about the plants.
Minute, elongate, pale yellow insects attack the leaves, causing them to wilt.