Abstract: The types and the characters of acoustic behaviors by larvae living in host timbers in the longhorned beetles, Nadezhdiella cantori (Hope) and Apriona germari (Hope), were studied. In larval living hosts, vibrational sounds areproduced by their feeding and crawling activities. In feeding sounds, the pulsetrain (PT) has higher amplitude but shorter lasting (about 60ms) of time, andthe maximum vibration frequency may reach to 700Hz. While in crawlingsounds, the PT has lower amplitude but longer lasting (100-300ms), and themaximum frequency is lower than 300Hz. The frequency analysis revealed thatthe feeding sounds are different between two species. The power-spectrum offeeding sounds in N. cantori consists of two peaks and the second one (MPF424+43Hz, n=13) takes the main part of signal energy. Though the spect-rum of feeding sounds in A. germari is also formed mainly by two peaks,the signal energy is given by the first peak (MPF=359+23Hz, n=16, timberⅠ; MPE=293+26Hz, n=24, timber Ⅱ) principally. Liited by detecting techniques, the characters of this larval produced solid-born sounds could notbe determined precisely here.

Key words: Cerambycidae, Larva, Acoustic behavior