4S- SECOND ANNUAL REPORT OF 



about the middle of June, and in Maine about the middle of July. In 

 every locality the worm goes underground about a month afterwards 

 to assume the pupa or chrysalis state, and stays underground between 

 two and three weeks. Hence, in the southern part of this State the 

 moth appears about the fore part of June, and a month later in each 

 successive locality as we go north, till in Maine, the period becomes 

 the fore part of September. Of course, these dates will vary some- 

 what with the character of the seasons, and sometimes from local 

 causes; but, broadly speaking, they will hold good. 



The moths soon pair, and sometime during the summer and fall 

 months, deposit their eggs in the positions already indicated. Many 

 eggs are thus deposited in tame meadows, but there is little doubt in 

 my mind that the great bulk of these eggs are deposited in low, damp 

 situations, and if the fall should prove wet, instead of dry, many of 

 them would perhaps get drowned out, and we should thus have 

 another potent influence at work to decrease the numbers of the 

 worm the succeeding year. I make this suggestion with all due con- 

 sideration, for I have long since concluded that the instincts of 

 insects, as of some of the higher animals, are not always sufficient to 

 guard against all contingencies. It has been demonstrated beyond 

 the possibility of a doubt, that the Plum Curculio deposits its eggs in 

 fruit that overhangs water, and in other positions where the grub 

 must inevitably perish ; and certain flesh-flies are well known to 

 deposit their eggs, by mistake, on flowers which have a putrescent 

 smell. Darwin has remarked that a small South American bird 

 (Furnarius cunicularius) which builds its nest at the bottom of a 

 narrow, cylindrical hole, which extends horizontally several feet 

 underground, is so incapable of acquiring any notion of thickness, 

 that, although he saw specimens constantly flitting over a low clay 

 wall, they continued vainly to bore through it, thinking it an excel- 

 lent bank for their nests.* Many such instances of misdirected in- 

 stinct might be cited, and they all lead me to believe that the female 

 Army-worm moth would be just as likely to lay her eggs in situa- 

 tions where they would drown out, as in situations more favor- 

 able. 



The above may be considered as the normal habit of the Army- 

 worm; but exceptional individuals occur, perhaps one in a hundred, 

 but demonstrably not as many as one in twenty, which lie in the 

 chrysalis state all through the winter and do not come out in the 

 moth state till the following spring. The proportion of those which 

 lie over till spring is doubtless greater in the more northern States 

 than it is with us. The great fault which Mr. Walsh made in his ex- 

 cellent paper on this insect, published in the Illinois State Agricul- 

 tural Transactions for 1861, was, that he drew his lines too rigidly, 

 and allowed of no exceptions to the rule which he laid down, of its 

 single-broodedness. He also fell into an error in roughly estimating 



*Voyage Round the World, p. 95. 



