. The Bulletin of the North Carolina Department of Agriculture. Agriculture -- North Carolina. The Bulletin. 29 these weeds be kept down in the vicinity of the tobacco field, other- wise they will furnish crop after crop of horn worms for the tobacco field. Natural Enemies.—Living exposed upon their food plants as they do, Horn Worms are subject to the attacks of a number of natural enemies. Chief among these natural checks is a kind of bacterial disease which causes the worms to turn black, shrivel up and die. Every tobacco farmer is aquainted with the work of the small four- winged parasitic
. The Bulletin of the North Carolina Department of Agriculture. Agriculture -- North Carolina. The Bulletin. 29 these weeds be kept down in the vicinity of the tobacco field, other- wise they will furnish crop after crop of horn worms for the tobacco field. Natural Enemies.—Living exposed upon their food plants as they do, Horn Worms are subject to the attacks of a number of natural enemies. Chief among these natural checks is a kind of bacterial disease which causes the worms to turn black, shrivel up and die. Every tobacco farmer is aquainted with the work of the small four- winged parasitic fly. This parasite lays its eggs upon the Horn Worm and the larvae live in the interior of the Horn Worm until full grown. When full grown they come to the surface, where they spin white oval cocoons. Horn Worms covered with these cocoons are frequently seen in tobacco fields. (Fig. 15.) Such worms should. Fig. 15. —Larva of Southern Horn Worm with_cocoons of a para- site, slightly reduced. (Photograph by the author.) not be destroyed, for their days for doing damage are practically over, and the parasites issuing from them would mean the destruc- tion of an increasing number of Horn Worms in the next generation. Several kinds of two-winged flies have also been reported as enemies of horn worms. Control. Preventives.—Fall and winter plowing, if deep, has a tendency to expose the over-wintering pupse to the action of heat and cold, thus killing a great many. All weeds should be kept down in the tobacco field, especially such weeds as are naturally food plants for the Horn Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original North Carolina. Dept. of Agriculture. Raleigh : State Board of Agriculture
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Keywords: ., bookcollectionbiodiversity, bookcollectionnybotani, bookyear1907
