A fiber optic distributed acoustic sensing, DAS, system for detecting a red palm weevil, RPW, the DAS system comprising: an optical fiber configured to be wrapped around a tree; and a DAS box connected to the optical fiber, the DAS box comprising a light source configured to generate a continuous-wave light; a light modulator configured to modulate an amplitude of the continuous-wave light emitted by the light source to generate a modulated light; a circulator configured to receive the modulated light and inject the modulated light into an optical fiber; and a processing unit that is configured to receive a filtered Rayleigh signal reflected by the optical fiber run the filtered Rayleigh signal through a neural network system (1100, 1500) to determine a presence of the RPW in the tree, wherein the DAS box further comprises a fiber Bragg grating configured to receive and band-pass filter a reflected Rayleigh signal to generate the filtered Rayleigh signal, wherein the band-pass filtering passes reflected Rayleigh signals between 200 Hz and 800 Hz, and wherein the neural network determines the presence of the RPW in the tree based on a signal-to-noise ratio of the filtered Rayleigh signal at a position of the tree, defined as the ratio between the root-mean-square value of the time-domain signal at the tree position and the value of the time-domain signal at a reference fiber section having a 5 m length. an optical fiber configured to be wrapped around a tree; and a DAS box connected to the optical fiber, the DAS box comprising a light source configured to generate a continuous-wave light; a light modulator configured to modulate an amplitude of the continuous-wave light emitted by the light source to generate a modulated light; a circulator configured to receive the modulated light and inject the modulated light into an optical fiber; and a processing unit that is configured to receive a filtered Rayleigh signal reflected by the optical fiber run the filtered Rayleigh signal through a neural network system (1100, 1500) to determine a presence of the RPW in the tree, wherein the DAS box further comprises a fiber Bragg grating configured to receive and band-pass filter a reflected Rayleigh signal to generate the filtered Rayleigh signal, wherein the band-pass filtering passes reflected Rayleigh signals between 200 Hz and 800 Hz, and a light source configured to generate a continuous-wave light; a light modulator configured to modulate an amplitude of the continuous-wave light emitted by the light source to generate a modulated light; a circulator configured to receive the modulated light and inject the modulated light into an optical fiber; and a processing unit that is configured to receive a filtered Rayleigh signal reflected by the optical fiber run the filtered Rayleigh signal through a neural network system (1100, 1500) to determine a presence of the RPW in the tree, wherein the DAS box further comprises a fiber Bragg grating configured to receive and band-pass filter a reflected Rayleigh signal to generate the filtered Rayleigh signal, wherein the band-pass filtering passes reflected Rayleigh signals between 200 Hz and 800 Hz, and wherein the neural network determines the presence of the RPW in the tree based on a signal-to-noise ratio of the filtered Rayleigh signal at a position of the tree, defined as the ratio between the root-mean-square value of the time-domain signal at the tree position and the value of the time-domain signal at a reference fiber section having a 5 m length.