INSECTS. 



short intervals, and could be distinguished at about twenty yards' dis- 

 tance." Later observers have discovered the mechanism producing the 

 noise ; it is a drum-like organ in the base of the fore wings. Some i ; our 

 own species also produce a noise, but not nearly so Loud as in the i 

 mentioned. 



One of our most common butterflies, a dark red species marked with 

 black, is represented in Figure 286. Its larva feeds upon various 1 1 

 the apple, plum, oak and willow, but is not abundant enough to do much 

 damage. It is remarkable among our insects for the case of mimicry it 

 presents, as in its general appearance — colors and style of ornamentation 

 — it closely resembles the common milkweed-butterfly, which structurally 

 is greatly different from it. 







