Saturday, August 27, 2011

The Army Worm - A 19th Century Account of Infestations & How to Combat the Army Worm

THE ARMY WORM, Mark Vernon Slingerland, Bulletin 133. April, 1897. Cornell University Agricultural Experiment Station.


"Apparently the native home of the army-worm is in North America, although it is known to occur in England, South America, India, Java, Maderia, Australia and New Zealand, thus making it nearly a cosmopolitan insect. However, it is known as an especially injurious insect only in the United States, east of the Rocky Mountains and in Canada. '' The region in which it especially flourishes extends from Iowa to Maine and from Texas to Alabama. East of the Blue Ridge Mountains its southerly range as an injurious species extends to North Carolina. The moth is often captured outside these limits and frequently in considerable numbers, but the caterpillar does not seem elsewhere to be a factor in agriculture.""

"1743 is always mentioned as the first army-worm year of which we have pretty definite proof. Perhaps it was the army-worm that appeared by the millions in Massachusetts in 1762 and ate up the corn. Graphic and definite accounts have been recorded of the ravages of the insect in New England in 1770 and 1790. The next army-worm year was in 1817, and since 1825 the insect has appeared in injurious numbers somewhere in the United States almost every year; but rarely, if ever, has the insect been destructive in the same locality in two successive years."

"The army-worm was known in the early chronicles as "the black worm;" just when it came to be known as "the army worm" we have not ascertained. Sometime in the latter part of the eighteenth century, a specimen of the adult insect—the moth, found its way into the then celebrated collection of a Mr. Francillon in London. Upon the breaking up and sale of that collection early in this century, this moth passed into the possession of a Mr. Haworth, who published a description of it in 1810; he named it unipunda, the white speck."

"It is a curious fact that no one seems to have discovered what the parents of the army-worms were like until 1855, when Mr. Kirkpatrick reared some of the moths in Ohio. It was not until 1861 that Dr. Fitch, then State Entomologist of New York, identified the army-worm moth as the same insect which had been described in England fifty years before."


During the spring and summer of 1896, the army-worm appeared in destructive numbers in portions of ten states, constituting what is probably the most serious outbreak of the pest known in the history of the country. In some states most of the damage was done in May, but usually it was the July brood which appeared in almost incredible numbers; in a few localities, however, it was not until September that the pest was seen in injurious numbers.

Nearly all kinds of field crops were ravaged by the caterpillars. Corn and oats seem to have suffered the most; there is no data upon which to base any definite estimates, but one may safely say that thousands of acres of these two crops alone were ruined by the worms in New York. In many localities, rye, barley, wheat, millet, meadows, pasture lands, and Hungarian grass suffered.

To fully realize the destructive capabilities of the insect one must see, no description will suffice, an army of the worms on the march and at work. In most cases, the caterpillars in each of these armies must have been numbered by the millions; even an approximate estimate of the number of worms in a single army would have been impracticable. Oftentimes when an army was marching across a lane or roadway, nearly the entire surface of the ground for several rods would be covered with the crawling mass of worms; one could not step without crushing several of them.

They soon strip all the leaves from the stalks of oats, rye, and similar plants, and often cut off many of the heads, leaving them uneaten on the ground. In one instance, a barn loomed up before the worms directly in their line of march, but nothing daunted, many of them valiantly scaled the perpendicular wall and soon succeeded in getting over the eaves onto the roof. Here, however, they met their Waterloo, either from the exposure on the heated shingles to the sun's rays or from other causes, and a windrow of dead worms was formed under the eaves.


". . . However, the worms can be prevented from entering other fields, and may, in many cases, be checked and killed even after they have entered a new field; in some cases, especially in corn fields, an advancing army may be stopped in the middle of the field and thus half of the crop saved. The simplest and most effectual method of doing this is to either dig a smooth-walled ditch, or plow several deep parallel furrows in front of the invading army; the perpendicular, smooth side of the plowed furrow should be towards the field to be protected. The worms not being readily able to scale the perpendicular wall of the ditch or furrow will drop back and begin crawling along the bottom seeking an easier place of ascent."

"If deep holes have been dug in the ditch or furrow at intervals of a few feet, the worms, in their wanderings, readily tumble into these holes and cannot get out. Bushels of them have been trapped in this way, and then killed with a little kerosene or by burning some straw scattered along the furrow. The holes or pits in the furrows are very essential to the success of this preventive method. It has been aptly said: "To one who has never before seen the army worm in its might, the sight of the myriads as they returned thwarted in their endeavors to cross a ditch or furrow, or of the living, moving, and twisting mass which sometimes fills a ditch to the depth of several inches, it is truly interesting." "

"In some soils a little extra work will be necessary to keep one side of the furrow perpendicular and to keep the earth loose and friable in the furrow; some accomplish the latter by dragging brush along the furrow. A ditch or several furrows well taken care of in this way will afford an almost impassable barrier to the worms, as many, who followed the directions carefully last year, can testify. It is such an easy matter to make a furrow and as one is not so effectual a barrier as a ditch, we advise that two or more parallel furrows be made, so that the worms which may scale the first one will be confronted by another."

"A strip of coal tar will effectually stop the worms as long as it remains sticky, but it has to be renewed once or twice a day and is thus expensive."

"When the worms can be confined to a small area by a ditch, it may be practicable to spray this area with a strong Paris green mixture to poison the worms. Sometimes much can be done to lessen their numbers by drenching with Paris green a narrow strip of the crop on the side toward which the army of the worms are marching, or even a strip just ahead of the worms in an infested field. A bran mash, to which enough Paris green has been added to give it a distinct greenish tinge, scattered about where the worms are at work will attract and poison many of them."

"In fighting army-worms, it is necessary to act quickly, for a day's delay often means the destruction of an acre or more of a promising rye, corn, oat, or hay crop. Stop the onward progress of the worms, or confine them in a limited area if practicable, with ditches or deep furrows in which holes have been dug every 10 or 15 feet. Then kill as many of the worms as possible, either in the holes in the furrows, or by the use of poisons, or invite the poultry to a feast."
European Whitestorks feeding on Army Worms, Soysambu Conservancy,

"What a feast many of the birds, including chickens and turkeys, had last year in those localities where the army-worm was numerous. On July 23d, Mr. L. T.Yeomans, of Walworth, N. Y., wrote us: "We think we have disposed of the greater share of our army-worms. The birds were our greatest helpers. They came in flocks—blackbirds, thrushes, and even the English sparrow condescended to help."

"Mr. F. A. Sirrine, of the New York Experiment Station staff, has reported that in addition to the birds just mentioned, the cowbird, catbird, robin and the lark were seen feeding on the worms at Washingtonville, N. Y. He states: "It was at first doubted whether the sparrows were in the oat field on a legitimate errand, but close observation showed that each old bird was carrying from one to four worms to its young."