FIG. 41—ADULT MOTH, OR PARENT OF TOMATO FRUIT WORM
(From Chittenden, U. S. Department of Agriculture)
The tomato fruit worm (Fig. 40) known as the bollworm of cotton and the ear worm of corn, is frequently the cause of serious trouble to tomato growers, especially in the southern states, due to its pernicious habit of eating into and destroying the green and ripening fruit. For its control it is advisable not to plant tomatoes in proximity to old corn or cotton fields, nor should land be used in regions where this species is abundant until it has been fall or winter plowed. Sweet corn planted about the field before the tomatoes are set will serve as a lure for the parent moths to deposit their eggs, corn and cotton being favorite foods of this species and preferred to tomatoes. The fruit worm feeds to a certain extent on the foliage before penetrating the fruit, and it is possible to keep it in subjection by spraying with arsenicals as advised for the flea-beetles. It is suggested that arsenate of lead, being more adhesive than other arsenicals, should be used for the first sprayings, beginning when the fruit commences to form, repeating once or twice as found necessary, and making a last spraying with Paris green within a few days of ripening. This last poison will readily wash off and there is no danger whatever of poisoning to human beings, as has been conclusively proved in numerous similar cases. For the perfect success of this remedy the last spraying is essential, as those who have sprayed with an arsenical and have reported only partial good results have discontinued within about two weeks of the time of the ripening of the first fruit.
White fly or aleyrodes.—These minute insects are familiar to most growers who raise tomatoes under glass. They can be held in control by vaporization or fumigation with tobacco or nicotine extracts, or by spraying with kerosene emulsion or the so-called whale-oil (fish-oil) soap. Care is necessary in using the extracts that the smudge does not become too dense and injure the plants. Before applying this remedy on a large scale a preliminary trial should be made following the directions on the packages, and reducing the amount if any ill results follow. Hydrocyanic acid gas, properly used, is also an excellent remedy for aleyrodes, aphides, "mealy-bug," and other soft-bodied insects which are sometimes troublesome on greenhouse tomatoes.
For a complete account of the methods of making and handling hydrocyanic acid gas, see Professor Johnson's book entitled "Fumigation Methods," published by Orange Judd Company, of New York. Sent postpaid for $1.—[Author.
CHAPTER XX
Tomato Diseases
By W. A. Orton
U. S. Department of Agriculture