46 SECOND ANNUAL REPORT OP 



Thus the fact becomes at once significant and explicable, that 

 almost all great Army-worm years have been unusually wet, with the 

 preceding year unusually dry, as Dr. Fitch has proved by record. 

 The appearance of this insect last summer in the West forms no ex- 

 ception, for the summer of 1868 was unusually dry and hot, while 

 that of 1869 was decidedly wet. I may remark here, in further cor- 

 roboration of these views, that, as might have been expected, no 

 Army-worms were noticed last year in the Eastern States; for though 

 in the summer of 1868 we of the West suffered so severely from 

 drouth, yet in the East they were blessed with the usual amount of 

 rain- fall, and in some sections had even more than the average 

 amount. 



There is in reality nothing in the least mysterious in the sudden 

 appearance and disappearance of the Army-worm, for the truth of 

 the matter is, that there are a few of these insects in some part or 

 other of the country every year, and I have for the past four or five 

 years captured one or more specimens of the moth every fall. The 

 eggs hatch during the early part of May, in the latitude of South Illi- 

 nois and South Missouri, and the young worms may feed by millions in 

 a meadow without attracting attention ; but when they have become 

 nearly full grown and have stripped bare the fields in which they 

 were born, and commence to march as described above, they neces- 

 sarily attract attention, for they are then exceedingly voracious, 

 devouring more during the last three or four days of their worm-life, 

 than they had done during the whole of their previous existence. As 

 soon as they are full grown they burrow into the earth, and, of course, 

 are never seen again as worms. 



Their increase and decrease is dependent on even more potent 

 influences than those of a climatic nature. The worms are attacked 

 by at least eight different parasites, and when we understand how 

 persistent these last are, and how thoroughly they accomplish their 

 murderous work, we cease to wonder at the almost total annihilation 

 of the Army-worm the year following its appearance in such hosts. 

 In the words of the late J. Kirkpatrick "their undue increase but 

 combines the assaults of their enemies and thus brings them within 

 bounds again." 



We must also bear in mind, that besides these parasitic insects, 

 there are some cannibal insects, such as the Fiery Ground- beetle 

 ( Calosoma calidum, Fabr.) and its larva,* which prey unmercifully 

 upon the worms, while the "Mosquito Hawks" (Zibellulce) and bats, 

 doubtless destroy many of the moths. Hogs, chickens and turkeys 

 revel in the juicy carcasses of the worms, and sometimes to such an 

 extent that, as I am informed by Mr. T. R. Allen, of Allenton, the 

 former occasionally die in consequence, and the latter have been 

 known to lay eggs in which the parts naturally white, would be green 

 when cooked. Small birds, of various kinds, and toads and frogs also, 



*First Report, Fig. 34. 



