: The ability to ‘listen’ for trouble within trees may just be the breakthrough that cashew farmers need. Researchers have developed a new acoustic detection method to identify infestations by the cashew stem and root borer (CSRB), a pest responsible for the loss of up to 10% of productive trees annually. “Acoustic detection methods played a significant role in identifying grain and wood-boring insect pests,” said experts from the ICAR-CCARI (Indian Council of Agricultural Research-Central Coastal Agricultural Research Institute). They added, “It is a rapid, non-destructive, and automatic monitoring of hidden insect pests. We standardised a methodology for the detection of the CSRB infestation in cashew.” Scientifically known as Neoplocaederus ferrugineus, this pest is responsible for significant tree destruction. “It causes damage to the extent of 10% of productive tree loss every year,” the ICAR-CCARI scientists said. The challenge with the CSRB lies in its concealed nature. The grubs of this pest are tissue borers, making their presence difficult to detect until substantial damage occurs. Symptoms of infestation are rarely visible at the initial stages, and once the trees reach advanced stages of infestation, recovery is nearly impossible. Therefore, early detection is paramount to prevent the borer from wreaking further havoc on cashew plantations. To combat this pest, researchers have devised an innovative acoustic detection methodology that is non-destructive, rapid, and capable of identifying hidden insect infestations early. This allows for timely management interventions. The standardised methodology unfolds in four distinct stages. The first stage involves the acquisition of acoustic signals emitted from a cashew tree using a specialised acoustic sensor setup. These signals are then processed through a technique called empirical mode decomposition, which helps extract intrinsic mode functions (IMFs) in the second stage. In the third stage, researchers compute the IMFs. The final stage employs machine learning algorithms to analyse these features and ascertain whether the stem borer is present. “The detection performance of the acoustic device under field conditions shows that infested trees are correctly detected with 70% accuracy,” the ICAR-CCARI experts said. “This will be useful in timely identification of stem and root borer-affected trees in cashew plantations to initiate management measures.” This project is funded by the Science and Engineering Research Board, Govt of India.