Primary Study On Sound Monitoring Technology Of Wood Boring Insects

As a major type of forest pests, tree trunk borers have devastating effects on forests. Their hidden hazards and delayed reflection cause difficulty in early monitoring.In this study, we use sound detecting method to research on the audible signals of Dendroctonus valens (LeConte) adults' crawling and larvaes' feeding, Semanotus bifasciatus (Motschulsky) adults'crawling and larvaes'feeding and crawl, Anoplophora glabripennis (Motschulsky) adults' threatening and feeding, and Apriona germari (Hope) larvaes'feeding and crawling, and have reached the following conclusions:â‘ We use the self-assembled sound signal acquisition system (including an AED-2000 portable sound detector, an R-09 portable recorder, a set of Sony monitor headphones, and an IBM Z60t notebook computer) to collect pest vibration sound signals. And we use the signal analysis system (the MATLAB signal processing toolbox and the Goldwave audio processing software) to complete signal post-processing, revealing the signal features such as time domain, frequency domain and time-frequency domain.By comparing the vibration audible signals of different pests, we sum up the differences between vibration acoustic signals of different pests. The results show that each insect has its unique acoustic signal frequency, and the characteristics of insects are different between species within the same family as well as between different families. The test result also showes that it is feasible to use sound monitoring technique in early monitoring of tree borers.â‘¡The sound of adult crawling is like intermittent "pop, pop", whose acoustic signal pulse duration is short, less than 150.00ms. Their signal frequency is low, around 600.00Hz or so. The acoustic signal pulse duration from adult crawling is related to body size and movement speed, i.e. the higher the speed, the shorter the duration and interval, and vice versa. â‘¢The pulse duration of Apriona germari feeding is short, which is 30.00-40.00ms, while the pulse duration of the other two pests are longer, about 50.00-130.00ms; the frequency of Apriona germari feeding is 843.80Hz, that of Dendroctonus valens is 516.00Hz, and that of Semanotus bifasciatus Motschulsky is 187.50Hz.â‘£The acoustic signal of larvae crawling is unstable, and the time domain is irregular; the frequency domain of larvae crawling is narrow, less than that of the feeding signal, of which the frequency of Semanotus bifasciatus larvae crawling is 187.50Hz, and that of Apriona germari is 140.60Hz.