Ultrasonic emission of noctuid moths (Lepidoptera, Noctuidae): Maincharacteristics of signals and possible mechanisms of their generation[Russian]

摘要

Morphological and acoustic studies of the sound-producing mechanism in noctuid moths were carried out on Amphipyra perflua F. Two laterally symmetrical pairs of complementary areas adjacent to each other are responsible for generating ultrasonic bursts. One pair is located on the ventral surface of the forewing base, the other occurs on the metascutum. The surface of these areas is covered with cone-like structures (aculeae) of 18-25 mkm high located at an angle to the basal surface. The density of aculeae reaches 3 per 100 mkm(2). The aculeae of complementary areas are oriented towards each other and can serve as a coupling mechanism between wings and the metascutum. While uncoupling, these structures produce an ultrasonic pulse. The moths with these structures removed are not capable of emitting clicks. Noctuid moths produce ultrasonic clicks during flight. The peak amplitude of these clicks varies from 79 to 84 dB SPL at a distance of 5 cm from the moth, the mean duration of them is 67 mks. The clicks have a broad-band (more than 100 kHz) spectrum with main peaks at 57 and 78 kHz. The artificially generated clicks have a similar spectrum. The regular pattern of emission with one click per every second or every third wing beat were often observed in nature and in conditions of tethered flight. The adaptive importance of the acoustic behavior of moths is discussed.