﻿OP THE STATE ENTOMOLOGIST. 47 



allel, as in Texas, early in March, and about a week later with each 

 degree of latitude as we advance northward. Thus in South Missouri 

 they commence to march about the middle of May ; in Central Mis- 

 souri the first of June, and in the extreme northern part of the State 

 about the middle of the month. In the more northern New England 

 States they seldom do much damage before the middle of July. There 

 may, therefore, be a difference of over two months between the 

 appearance of the worms in Southern Missouri or Kentucky and in 

 Maine. Thus early in June of the present year, when I left home^ 

 they were mowing down the meadows and wheat fields in Central 

 Missouri and in Southern Illinois, Ohio, Indiana, as well as in Ken- 

 tucky ; while upon arriving in New York two months later, they were 

 marching through the oat fields of Long Island, and were reported 

 very generally in the Eastern States. In Maine they appeared as late 

 as September. 



ARE THERE OXE, OR TWO BROODS EACH YEAR? 



All the evidence, and the whole history of the insect as here set 

 forth, point to its one-brooded character, at least in ordinary seasons, 

 and north of the 3Sth parallel. In the more northern States, it is evi- 

 dent, from the lateness of the season when the worms enter the 

 ground, that those which issue as moths the same season cannot beget 

 a second brood, since the ovaries are so immature at the time of issu- 

 ing. There is in fact no actual evidence of its 2-brooded nature. One 

 of the arguments brought forward in support of the theory, is that it 

 is difficult to conceive how an insect that produces but one brood 

 annually can become at times so prodigiously multiplied. But it is 

 only at long and irregular intervals that it does become so prodig- 

 iously multiplied, and after such a wide-spread appearance of it in 

 our cultivated fields as that of 1875, it takes several years of undis- 

 turbed and unnoticed multiplication, culminating in unusually favor- 

 able conditions, before the decimation of its ranks that inevitably fol- 

 lows such undue increase, is repaired, and this notwithstanding its 

 great prolificacy. It is an interesting fact, also, that most Lepidopter- 

 ous insects that have a wide geographical range and the peculiarity 

 of appearing suddenly and at irregular intervals in vast swarms, are 

 known to be single-brooded; while most of our cut- worms, its close 

 allies, I have by experiment proved to be so. The second argument 

 in support of the 2-brooded nature of our Army Worm is, that accounts 

 are often heard of the Army Worm appearing in the Fall of the year, 

 but in every instance where I have been able to obtain specimens for 

 examination, they have proved to be 



