﻿50 EIGHTH ANNUAL REPORT 



within comparatively narrow limits. — [Collinville, Ills., correspondence of Missouri 

 Democrat, June, 1860. 



Mr. Ed. Dixon informed us Saturday that the Army Worm had destroyed tAventy 

 acres of timothy for him. From the meadow they entered the wheat fieid, and de- 

 stroyed every stalk of cheat, leavino^ the wheat unhurt. Mr. Dixon ditched between 

 his wheat and corn-field, and with the aid of a dozen or two pigs succeeded in arrest- 

 ing their progress and destroying them. This is about the experience that many far- 

 mers have had in this county. They can be prevented from doing harm by determined, 

 vigorous opposition. — [Jetterson City Tribune, June 16, 1875. 



The habit of merely stripping the blades off the wheat stalks was 

 very general last summer, and a large number of farmers report that 

 the work of the insect was beneficial to wheat, as the rains were very 

 constant and copious and the grain denuded of its leaves ripened bet- 

 ter than it otherwise would have done. 



ITS SUDDEN APPEARANCE AND DISAPPEARANCE. 



Among the manifestations in lower animal life, few are more as- 

 tonishing than the sudden occurrence of a species in vast numbers 

 over large stretches of country, and its as sudden disappearance. In 

 a few rare instances, as with the thirteen and seventeen-year Cicadas, 

 these manifestations are strictly periodical, and occur at regular inter- 

 vals ; but in the great majority of instances they have no such periodi- 

 city. The numerous natural checks which surround every animal, ad- 

 ded to the meteorological conditions which affect it in its "struggle for 

 existence," sufficiently explain these phenomena to the intelligent 

 naturalist, though it is not always easy to point out the facts in spe- 

 cific cases. 



Under the head of "Habits of the Worm," I have already given 

 the reasons why it escapes attention in its earlier stages and in sea- 

 sons when it is not excessively abundant. If, as from what has gone 

 before we may justly conclude, the natural abode of the worm is in 

 our low prairie lands and swampy places, it follows that during a very 

 dry season, when such lands dry out, the worm has a wider range than 

 usual,where the conditions for its successful development are favorable. 



It is a well established fact that all great Army Worm years have 

 been unusually wet, preceded by one or more exceptionally dry years ; 

 and the wide-spread appearance of the insect in 1875 formed no ex- 

 ception to the rule. The explanation of this fact originally given by 

 Dr. Fitch,* is beyond doubt correct in the main, but needs further 

 elucidation. Dr. Fitch's views, in his own words, are given in the fol- 

 lowing paragraphs : 



The Spring and early summer of this 'year [ISCl] was exactly the reverse of last 

 year— unusually wet, and the writer high in all our streams. Hereby the swamps have 

 all been overllowed, and this insect has been drowned out of them. [11 The moths or 

 millers on coming out of tlieir clirysalides, found it was impossible lor them to get to 

 the roots of the grass there, to deposit their eggs. Tliey were obliged to forsake tlieir 

 usual haunts and scatter themselves out over ttie country, the incessant rains making 

 it sutiiciently wet everywhere to suit their semi-aquatic habits. Thus going forth in 



•6thN. Y. Rep., 121. 



