An integrated system for detecting a red palm weevil, farm fire, and soil moisture, the system comprising: an optical fiber comprising a sensing Fiber Bragg Grating and a reference FBG, and configured to be extending to a tree; and a distributed acoustic sensor box connected to the optical fiber, wherein the DAS box is configured to process first to fourth different optical signals (422, 434, 432, 436) reflected from the optical fiber, to determine a presence of the RPW from the first optical signal, a temperature at a location along the optical fiber from the second and third optical signals (434, 432), and moisture at a location around the tree from the fourth optical signal, wherein the DAS box comprises a laser device configured to generate a first optical pulse, which, after propagating through the optical fiber, generates the first reflected Rayleigh optical signal, the second reflected Stokes Raman optical signal and the third reflected Anti-Stokes Raman optical signal, and an optical amplifier configured to generate while the laser device is switched off a second optical pulse, which is different from the first optical pulse, and after the second optical pulse propagates through the optical fiber, generates the fourth FBG-reflected optical signal, wherein the optical amplifier is optically connected to the laser device and is configured to amplify the first optical pulse; a wavelength-division-multiplexing filter having first to third input ports and a common output port, wherein the common output port is connected to the optical fiber and is configured to pass along the first and second optical pulses, wherein WDM filter filters a reflected signal from the optical fiber and provides the first and fourth optical signals to the first input port, the second optical signal to the second input port, and the third optical signal to the third input port, and wherein the first input port is optically connected to an RPW detection and moisture monitoring unit, and the second and third input ports are optically connected to a fire detection unit, both said units (420, 430) being part of the DAS box. an optical fiber comprising a sensing Fiber Bragg Grating and a reference FBG, and configured to be extending to a tree; and a distributed acoustic sensor box connected to the optical fiber, wherein the DAS box is configured to process first to fourth different optical signals (422, 434, 432, 436) reflected from the optical fiber, to determine a presence of the RPW from the first optical signal, a temperature at a location along the optical fiber from the second and third optical signals (434, 432), and moisture at a location around the tree from the fourth optical signal, wherein the DAS box comprises a laser device configured to generate a first optical pulse, which, after propagating through the optical fiber, generates the first reflected Rayleigh optical signal, the second reflected Stokes Raman optical signal and the third reflected Anti-Stokes Raman optical signal, and an optical amplifier configured to generate while the laser device is switched off a second optical pulse, which is different from the first optical pulse, and after the second optical pulse propagates through the optical fiber, generates the fourth FBG-reflected optical signal, wherein the optical amplifier is optically connected to the laser device and is configured to amplify the first optical pulse; a wavelength-division-multiplexing filter having first to third input ports and a common output port, wherein the common output port is connected to the optical fiber and is configured to pass along the first and second optical pulses, wherein WDM filter filters a reflected signal from the optical fiber and provides the first and fourth optical signals to the first input port, the second optical signal to the second input port, and the third optical signal to the third input port, and wherein the first input port is optically connected to an RPW detection and moisture monitoring unit, and the second and third input ports are optically connected to a fire detection unit, both said units (420, 430) being part of the DAS box.