THE AMERICAN ENTOMOLOGIST. 



215 



vicinity, and we found that the Army-worm was 

 even more numerous around New London, Mo., 

 and especially on Mr. A. McPikc's farm, which is 

 live miles north of that town . AV'e have also heard 

 of its appearance in other part's of Missouri, es- 

 pecially in Cooper and St. Louis counties, as 

 well as in St. Clair county, and in Coles and 

 Franklin counties, in Illinois, and we there- 

 fore take this opportunity of jfiving' a condensed 

 account of it, by which it may the more easily be 

 distinguished tVom the Southern Cotton Army- 

 worm, which formed the subject of our leading 

 article. It will be well remembered by the 

 people of the "West, and especially of Illinois 

 and Missouri, that the Army- worm was exceed- 

 ingly abundant and injurious in the year 1801. 

 Since that time it has never appeared so gener- 

 ally over such a vast extent of country, though in 

 1865 it appeared in considerable numbers around 

 St. Joseph, in Missouri, and in 1860 did some 

 damage near Quincy, 111., as we learned from 

 the Quincy Whiy. But in most of the locali- 

 ties where it so abounded in 1801 it has scarcely 

 been heard of since, and the unobsorving resident 

 in such localities would naturally conclude that 

 it had vanished from the fiiceof the country, and 

 would be not a little puzzled to divine from 

 whence it so suddenly came, iu such immense 

 armies, the present summer. 



The truth of the matter is, that there are a 

 few Army-worms iu some part or other of 

 the country every year, and we liavc for the 

 past four or live years captured one or more 

 specimens of the moth every fall. The worms 

 very possibly occur by preference, as has been 

 suggested by Dr. Fitch, in low sw!imi)y lands, 

 where they would be little likely to be noticed. 

 Occasionally circumstances are favorable to their 

 multiplication, and whenever such is the case, 

 their enormous fecundity enables them to 

 appear as if by magic. The eggs hatch dur- 

 ing the early part of May, in the latitude of 

 South Illinois and Missouri, and the young 

 worms may feed by millions iu a meadow with- 

 out attracting attention; but when they have 

 become nearly full grown and have stripped 

 bare the fields in which they were born, they arc 

 forced from necessity to travel iu search of fresh 

 flelds, and it is at such times that they first at- 

 tract general atteution. A curious instinct leads 

 them to travel iu vast armies, and as they arc 

 now exceedingly voracious, devouring more 

 during the last flu-ee or four days of their worm- 

 life than they had done during the whole of 

 their previous existence, they are very apt to 

 strip the leaves from every blade of grass or 

 grain on their way. On the other hand, they 



are attacked by at least five different parasites, 

 and when we understand how persistent these 

 last are in their attacks, and how thoroughly 

 they accomplish their murderous work, we cease 

 to wonder at the almost total annihilation ol the 

 Army-worm the year following its appearance 

 in such hosts. Furthermore there may be inllu- 

 ences at work, other than parasitic, which cause 

 an increase or decrease in the numbers of this 

 pest. It is a signilicant fact that almost all great 

 Army-worm years have been uuusually wet, 

 with the preceding year unusually dry, as Dr. 

 Fitch has proved by record. The present year, 

 wherever they have so far appeared, forms no 

 exception, for the summer of 1808 was unusually 

 dry and hot, while the present year has been 

 decidedly wet. 



The Army-worm, like all other insects, 

 hatches from an egg, and this egg is evidently 

 deposited by the parent moth at the base of pe- 

 rennial grass stalks. The worm varies but little 

 from the time it hatches to the time when it is 

 full grown. Some specimens are a shade darker 

 than others, but on many thousands of speci- 

 mens examined, we have found the markings 

 very uniform, as represented in the annexed 

 [Fig 1.5J ] cut (Fig. 1.02). When full 

 fed, which is generally about 

 four weeks after hatching, 

 it descends into the ground 

 where it forms an oval cham- 

 ber and changes to a shiny 

 mahogany-colored chrysalis 

 (Figure 153). tris. ik'O 

 Sometimes it 

 scarcely pene- 

 trates beneath "^ i.r'.'wli.'"'"" " 



the surface, but forms a rude 

 cocoon under what dry herb- 

 age there happens to be 

 on the ground. Thus, the 

 worms vanish from sight 

 very suddenly, and this 

 sudden disappearance is as mysterious (o 

 those who have no knowledge of natural his- 

 tory, as was their abrupt advent. We doubt 

 very much if a single one, of the hosts which so 

 recently animated the meadows, can be found 

 in any of the localities above mentioned, by tlu; 

 time this reaches the eyes of our reader's. 



After remaining in the chrysalis state abon( 

 two weeks, the jierfect moth appears. The gen- 

 eral color of the moth is light reddish-brown oi- 

 fawn color, and it is principally characterized by, 

 and receives its name from, a white spot near the 

 centre of its fore wings, there being also a dusky 

 obliiiue line running inwardly from their tips. 



