﻿48 NINTH ANNUAL REPORT 



moth invariably endeavors to secrete them. They are generally laid 

 in single rows of from five to twenty and upward, and they are 

 accompanied with a white, glistening, viscid fluid, which glues them 

 to each other and to the plant, and, when laid in the fold of a spear, 

 draws the two sides securely over them, leaving but a glistening streak 

 along the more or less perfectly closed edges. 



There is one other mooted question in the natural history of the 

 Army Worm which I have, the past Summer, been able to settle, viz. 

 whether the species is single or double-brooded. In the review of 

 the matter in my 8th Report, I came to the conclusion that, in the 

 more northern States at least, or over the larger portion of the country 

 in which it proves injurious, it is but single-brooded ; and I am still of 

 the opinion that such is the case. But I have proved that, like so 

 many other species which are single-brooded further north, it is fre- 

 quently, if not always, double-brooded in the latitude of St. Louis. By 

 carefully feeding the moths reared from my first larvjB with sweetened 

 water, and supplying them with grass in spacious vivaria, I succeeded 

 in obtaining eggs from them. These eggs in due time hatched, and 

 the second brood of worms gave me the moths again early in August. 

 The worms were generally paler than those of the first brood, and 

 being the second generation reared in confinement, they were less 

 healthy. I obtained, in consequence, but five moths, all of them 

 unfortunately females. One of these escaped, three died without 

 showing any development of the ovaries, while the fifth died with 

 the ovaries so well developed that the eggs, in a state of nature, 

 would probably have been laid within a week. This was about two 

 weeks after issuing or about the middle of August, and would indi- 

 cate that a third generation of worms may exceptionally be produced. 

 Indeed, by dilligent search out-doors I found larvae of different sizes 

 all through the month of August, and a few full grown individuals as 

 late as the 23d of September. Moths were also obtained as late as 

 October 9th from such worms. There is the greatest irregularity about 

 the development of individuals of the same brood and little doubt in 

 my own mind that while the production of a third generation of 

 worms is the exception it may some years prove the rule. 



The male moths, reared and fed in confinement, lived on an aver- 

 age 10 diys ; ihe females which were impregnated, twice as long, com- 

 mencing to lay about a fortnight after issuing. What I have previ- 

 ously said as to the longevity of these moths applies therefore to the 

 last or Fall brood only. The worms obtained the latter part of Septem- 

 ber entered the ground and were found dead upon subsequent exami- 

 nation, but would doubtless have hibernated in chrysalis and confirmed 



