AUDITORY POWERS OF CATOCALA MOTHS. 28 1 



('09) that the crackling of twigs under his feet and even the 

 slight noise made by removing the cork from his collecting bottle 

 disturbed this moth. In another article, the same investigator 

 ('io) has made a comparative study of the auditory powers of 

 day-flying and night-flying Lepidoptera. He investigated the 

 day-flyers; Apatura sp., Vanessa sp., Limenitis populi L., and 

 Sat. alcyone Schiff. He found that species of Apatura and of 

 Vanessa made no responses to sound so long as no visible object 

 disturbed them. During a severe storm, he noticed a number of 

 Sat. alcyone perching on a limb. Neither whistling, nor the 

 clapping of hands, nor shaking of the limb had any effect on them: 

 but, as soon as the hand of the collector approached them, they 

 flew. A Vanessa antiopa, resting on a telegraph pole, was not 

 disturbed by the shrill whistle and the rumbling noise of a passing 

 train. In studying Catocala fraxini L., a night-flying moth, he 

 noticed that it made no responses to the noises made by wagons, 

 automobiles and the bells of a ferry; but that it responded 

 readily to slight, high-pitched, sounds. He argues that the 

 failure of this moth to respond to the sounds made by wagons 

 and such things is because such sounds have no life significance 

 for the moth. On the other hand, the ready response to the 

 other sounds mentioned is due to their similarity to sounds made 

 by field-mice, bats and owls sounds which for the moth have 

 a pronounced life significance. Partly influenced by the knowl- 

 edge that Geegener had discovered chordotonal organs in the 

 Noctuidse and more so by the observations just described, 

 Richter is convinced that day-flying Lepidoptera are warned by 

 visual and night-flying forms by auditory stimuli. 



For years Rober ('io) has raised Acerontia atropos L. from 

 pupae. Late one evening a female emerged and, before her wings 

 were fully dried, a male emerged in the cage. In order to separate 

 the two, the female was removed to a cage in the bottom of which 

 there was a crack as wide as one's finger. These cages were three 

 meters apart. In the morning the female, which had escaped 

 from confinement, was found perched on the cage containing 

 the male. A person who slept in the room with these two moths 

 asserts that, for a long time that evening, those moths emitted 

 sounds. Rober concludes that these were love calls and that the 



