138 NORTH AMERICAN INSECTS. 



These insects are rarely seen by day, being concealed on 

 or under fences, or houses, or under the leaves of trees and 

 bushes, and you have only to strike upon a bush with your 

 walking-stick, or parasol (for I write also for the young 

 ladies), when a swarm of these insects will sometimes fly 

 out of it, and be easily caught in a net. As soon, however, 

 as night sets in, their airy promenades begin, and unless 

 snapped away by the cruel whip-poor-will, or a voracious 

 bat, or burned alive by the flame of some candle, they con- 

 tinue flying about all night. 



It is very singular that nocturnal insects, which conceal 

 themselves from the daylight, are so apt to fly toward a 

 light in the night. But such is the fact, as almost all can 

 testify who have seen them flying around a light in a warm 

 summer evening, when the windows are open, until they 

 disabled themselves, so that they could not fly. This is an- 

 other way of catching these insects ; and still another is to 

 spread a white sheet over the turf of your garden in a warm 

 summer evening, and set a lantern in the midst of it : nu- 

 merous swarms of guests of all shapes and colors will im- 

 mediately appear upon it. 



Fisure 29. 



Caterpillar of the Asterias. 



But if we examine these insects, which are so much at- 

 tracted by the light, we find the greatest part of them 

 males. Hence the celebrated and ingenious Professor 

 Oken thinks that the females of the nocturnal lepidoptera 



