HEIGHT OF FLIGHT: HABITS AT NIGHT. 219 



it was brought down it was literally covered with locusts. The most 

 convincing experience, however, is that of Professor Aughey's, given in 

 Chapter VII. In camping on the Bow Kiver, in August, 18GG, the wind, 

 which was blowing from the northwest, suddenly changed to north soon 

 after midnight, and locusts were heard pattering on his tent, and the 

 insects were found thick the next morning where none had been seen 

 the day before. 



Singularly enough we get no information from European writers on 

 the question of flight at night. 



That locusts are capable of long-sustained flight is evident from the 

 well-authenticated instances of their being observed at sea hundreds of 

 miles from land. One of the most striking instances is that recorded by 

 Master E. G. Wiswell, of the Harrisburg. When this vessel, ]N"ovember 

 2, 1805, was in latitude 25^ 28' north, longitude 41° 33' west, on her way 

 from Bordeaux to New Orleans, the nearest land being about 1,200 miles, 

 she was boarded during a heavy rain-storm by large numbers of locusts 

 that tilled the air and covered the sailt^. The specimens were subse- 

 quently determined to be the European Acridium j^erigrinum by Mr. S. 

 H. Scudder, who records the facts. 



HEIGHT OF FLIGHT. 



This subject has already been considered in Chapter YII (p. 141). 

 There is no doubt whatever that the insects often move over a coun- 

 try entirely above the reach of human vision. In ordinary flights we 

 observe only the lower individuals, and in looking toward the sun we 

 may always observe others, farther and farther away, until the glitter- 

 ing specks are lost to sight. In cloudy weather they are not noticeable 

 unless very dense, so as to darken the atmosi3here, until within about 

 1 000 feet ; yet it is well known that they fly at times nearly, if not full, 

 two miles above ground, as they have been seen flying toward the plains 

 as high above the highest peaks of the Eocky Mountains as a good tele- 

 scope would resolve them. 



GENERAL HABITS AT NIGHT. 



Regarding the general habits of the species at night, a glance at the 

 experience obtained in answer to our circulars (App. 17) is sufficient 

 to show that it difi'ers widely and is often contradictory. This is not 

 surprising, as so much in the habits and ways of our locust depends on 

 conditions of the weather, season, &c. We have had an extensive ex- 

 perience both with the unfledged and full-fledged insects, and the result 

 of it is that, as a rule, the young insects are quiet at night, either hid- 

 ing under some shelter upon the ground, or roosting away from the 

 ground. The former is more apt to be the case in cold, the latter in wet 

 weather. In cool weather even the mature insects do not feed at night, 

 but when the weather is warm and dry these are often as ravenous dur- 



