236 Annals Entomological Society of America [Vol. IX, 



do early in the evening, but dropped to the grass below, spread- 

 ing their wings to ease their descent. Here we have at once 

 conclusive evidence that this massing together of great numbers 

 does not afford protection from the birds, because they all 

 behaved thus stupidly, making no effort to escape when attacked 

 at an hour in the morning when the whole bird population is 

 alert and riotous with activity. I cannot say whether the 

 weather, light or some other factor caused their behavior to 

 differ this time from the previous morning experiment. 



About the middle of August a colony was found in a clump of 

 Erigeron canadensis. Night after night they returned to these 

 same four or five stalks, several hundred strong, and all males. 

 The whole made a pretty group; the tall, stately plants were in 

 themselves graceful; the stem for about one-third of its length 

 was literally covered with the delicate, bright-colored bodies, 

 while each slender leaf bore one, or occasionally two, on its 

 lower surface. 



On August 13, it was cloudy and dark at 6:30 a. m. About 

 two hundred males of Elis 5-cincta were still asleep on five plants 

 of Erigeron canadensis within a radius of three feet. They were 

 ranged without crowding in single file on the long, narrow 

 leaves and stately stems. When disturbed they dropped 

 languidly to the lower leaves or the ground. 



The next morning the gloom continued. At 10:15 a. m., 

 the Elis still remained on their customary sleeping-quarters, 

 too indolent to bestir themselves on a dull day. By 4 :30, a high 

 wind was blowing; they were rocked violently to and fro on 

 their tall stems without being stirred to flight, but the approach 

 of my forceps at once caused turmoil among them. By 6 :30 the 

 sun shone brightly, but Elis remained at home. 



On the same dull day three other colonies were found on the 

 under side of the broad leaves of some weed, but I cannot say 

 whether this was their regular sleeping quarters or whether they 

 had thus come together for only temporary shelter from the 

 threatened storm. One group comprised 25 individuals, another 

 15 and the other 12. 



A thick mass of weeds, especially Erigeron, bordering a 

 large, open space of ground, seems to be a favorite habitat of 

 Elis. In the middle of one such spot about two hundred yards 

 in length, we found a crowded clump of 27 plants each bearing. 



