57 



only hastens the ripening, without injuring the grain ; and it is only 

 of cool and rather moist seasons that the worms make their appear- 

 ance in migrating armies. 



These insects invaded the grassy portion of my own yard, thus fur- 

 nishing me an opportunity of observing them somewhat carefully. 

 They appeared suddenly at the northwest border, moving eastward, 

 and coming apparently from a grassy plat h r ing west of mine, with 

 an alley between. But looking into that yard from the fence, I could 

 see no worms, nor had the owner of the premises noticed any — we did 

 not carefully examine the grass in which they had doubtless remained 

 hid until starting on their migrations. They were about half grown 

 when they entered my premises. It is unnecessary to follow the his- 

 tory of these specimens any farther, than simply to add that they 

 were all destroyed by the chickens, birds and heat, as they had, in 

 their progress eastward, to cross a smooth croquet ground, where they 

 were exposed to the sun and their feathered enemies. 



During this time the southwestern portion of the lot, which was 

 covered with grass, seemed to be wholly free from worms. I walked 

 over it once or twice each day looking carefully for them but found 

 only one, and that was larger than those migrating, fully grown, and 

 looked and acted so much like the ordinary cut-worms that I felt un- 

 certain in reference to it. About the time the migrating worms dis- 

 appeared, I noticed comparatively large spots of grass in the undis- 

 turbed area (southwest) dying without any apparent cause. Visiting 

 a friend in a neighboring village about this time, I noticed the grass 

 in his door-yard dying apparently in the same manner. This he in- 

 formed me was caused by " cut-worms." At once suspecting the army- 

 worm, I made a careful examination and found them at work. Most 

 of them had already gone into the ground, and those that remained 

 were full-grown and presenting that peculiar appearance of the single 

 one already mentioned. Here then was evidence that this worm acts 

 in two roles : first, as a true cut-worm, working beneath the grass and 

 remaining hid from view ; and second, as social and migratory. Ex- 

 amining my own injured grass I found it cutoff and the surface of the 

 ground beneath it covered with the droppings of the worms which had 

 disappeared. As those which possessed the cut-worm habits, differed 

 somewhat in color and markings from the army or migratory worms, 

 it was necessary before my evidence was complete on that point, that 

 I should see the perfect insect or moth in order to prove specific 

 identity. Watching carefully the injured spots in my yard, I had the 

 pleasure on the evening of June 21st, of seeing a moth, a genuine 

 Lucania unipuncta make its appearance. Still I was not satisfied as I 

 did not see it come out of the ground, and even if I had this would 

 scarcely be satisfactory evidence. But each evening after that, un- 

 til the 25th, several made their appearance, and were seen com- 

 ing out of the ground of the injured area, were secured and identified. 

 Here then was complete evidence that those acting the role of cut- 

 worms were specifically identical with the migratory hordes. Another 

 fact worthy of note is, that those acting as cut-worms in the injured 

 areas must have been fully grown, and perhaps mostly entered into 

 pupa state, when the migratory portion entered and were yet but half 

 grown. The one set had no connection with the other ; and precisely 

 the same thing was true at my friend's locality referred to ; no 



