ARMY-WORM (Ciphis unipuncta or Leucania unipuncta of the family Noctuidae) is a small striped green, and nearly naked, caterpillar, found chiefly in the United States and Canada east of the Rocky Mountains, but also in New Mexico, Arizona, California and in some parts of South America. From time to time it becomes enormously destructive to growing cereals and sometimes to forage crops. The fully developed parent of the army-worm is a moth measuring about i in. across the expanded wings, brownish-gray in colour, and having a single small white spot near the centre of the front pair of wings. This moth lays its eggs on the under side of blades of grass, or grass-like grain, preferring marshes and low spots. There the worms hatch and grow rapidly. The greed and capacity of the full grown worm for food is most remarkable. When an army is at work in a field the champing of the jaws may be plainly heard as they devour every tender green blade in sight. When the worms have exhausted the food in the vicinity of their breeding place, they mass to gether and march (hence the name army-worm) in search of new fields. It is usually in this stage that they are first discovered.
If noticed in their younger stages the army-worm may be destroyed by burning the infested spot or by spraying heavily with a mixture of Paris green in the ratio of 1 lb. to 5o gal. of water. Spraying poison in their line of march is also useful but a more certain method is to plow around the infested area, throwing the earth toward the army so that the worms will have difficulty climbing the opposite and perpendicular side of the furrow and will crawl along the bottom instead. Here they may be destroyed by crushing, or by digging post holes about every 20 ft. in the furrow bottom, into which they will fall. Crude coal oil or petroleum can then be poured into the post hole.
See A. Gibson, "The Army-worm" (Dominion of Canada, Dept. of Agri., Entomological Branch, Bulletin No. 9, 1915) ; W. R. Walton, "The True Army Worm and its Control" (U.S. Dept. of Agri., Farmers' Bulletin No. 731, 1916) ; H. H. Knight, "The Army-worm in New York" (Cornell Agri. Exp. Sta., Bulletin No. 376, 1916) ; H. T. Fernald, "The Army-worm" (Mass. Bd. of Agri., 62nd Ann. Rept., 1915) .