Block diagram of the proposed system. • Characterised the acoustic sounds of Neoplocaederus ferrugineus (Linnaeus) (Coleoptera: Cerambycidae). • There were no significant differences between the number of bursts and various larval instars. • Predicted the likelihood of infestation of N . ferrugineus and field evaluated the detection performance of the acoustic device. • This is the first work on the acoustic behaviour of cashew stem and root borer. Stem and root borer Neoplocaederus ferrugineus (Linnaeus) (Coleoptera: Cerambycidae) is a severe pest of cashew ( Anacardium occidentale L), which affects the cashew tree heavily. The larvae are tissue borers that remain concealed inside the tree and are very difficult to detect at the initial stage of infestation. Adult attractants are not identified, and manual checking of each tree in a plantation is not feasible and laborious. Acoustic technologies have been developed for the non-invasive and early detection of wood borers. The present study was conducted to characterize the acoustic sounds of various larval instars, tissues and field evaluation of the commercially available acoustic device. Burst analysis of different larval instars in cashew logs shows that there are no significant differences between the number of bursts and various larval instars. A relatively less number of bursts are found when the larvae are in the sapwood region than the cambium region. The empty cashew log and healthy trees do not produce any significant noise. The number of burst counts and impulses are used to predict the likelihood of infestation. The detection performance of the acoustic device under field conditions shows that infested trees are correctly detected with 91% accuracy. The possibility of not detecting healthy trees is 85%. This is the first report on the acoustic behaviour of cashew stem and root borer. The results of the study will help in better understanding the acoustic behaviour of the hidden pest and also be useful in the timely identification of stem and root borer-affected trees in cashew plantations.