Experiment and development of monitoring system for Bactrocera Dorsalis (Hendel) based on wireless sensors network

Abstract: Bactrocera Dorsalis (Hendel) were invasive pests that were occurred frequently and were seriously harmful for fruit trees' growth and have been ranked an important quarantine object in many countries and regions. So far, the main prevention method for Bactrocera Dorsalis (Hendel) has been chemical pest control, which not only caused serious damages on the economic field but also brought on water and soil resources pollution, ecological system damages, damage to food security and its impact on human health, and a series of major problems. In order to detect the real-time number of Bactrocera Dorsalis (Hendel) and monitor the corresponding environmental information accurately in a large-scale orchard, a wireless sensor network was employed. The dynamic monitoring system included ten pest-sensor nodes, one environmental-sensor node, and one WSN+GPRS node, all of which were deployed in the national citrus industry experimental orchards at South China Agricultural University. TinyOS and ZigBee were applied as the operating system and the communication protocol respectively for all monitoring nodes. Mean current consumption for all monitor nodes ranged from 39.52 to 42.72 mA in standby mode and from 92.21 to 95.32 mA under full operating mode. Mean current consumption of the router was kept steadily around 190mA in standby mode, and rose to stay around 250mA under communications condition. The results showed that the solar powering module sufficiently met the system power requirements. The results of the five-month communication experiments indicated that the PLR of all monitor nodes obtained a stable range from 11.9% to 20.8%, which can meet the requirements for long-time monitoring, and the statistics of the PDR had a parabola curve distribution. It meant that the stability of communication was more correlated to crop canopies and atmospheric conditions according to the short-range radio signal propagation theory. It was highly recommended that the antennas be mounted to obtain a line-of-sight communication, if possible, to avoid signal attenuation and distortion introduced by crop canopies. In conclusion, the system achieved stable data transmission suitable for effective Bactrocera Dorsalis (Hendel) monitoring in a large-scale orchard.