Precision apiculture: Development of a wireless sensor network for honeybee hives

Wireless in-hive sensor networks show promise in apiary management and research. However, radio frequency electromagnetic radiation (RF-EMR) emitted by wireless technologies could affect honeybees at the individual and the colony level. Prior research has noted that different operation frequencies and power of transferred signals affect insect and larger animal behavior. An on-line wireless sensor network was developed that continuously monitored in-hive temperature, relative humidity, and acoustics. While testing the network performance, a wired version of the developed sensor network was used to substantiate whether or not RF-EMR from Wi-Fi affects the measured parameters through a 30-day study in 2015. Two groups of three beehives were monitored: the first group was subjected to 14 GHz Wi-Fi signal while the second group was located outside of radio communication range. During RF-EMR exposure, in-hive temperature increased by an average of 0.09C and relative humidity increased by 1.53%, sound increased in amplitude by 0.03 dB but decreased in frequency by 2.57 Hz. All measured parameters had a higher standard deviation (SD) during the exposure treatment as compared to these changes during RF-EMR exposure, thus differences were not significant at the p < 0.05 level However, Control hive 1 swarmed 2 months before the start of the experiment and was on average 14.4% less humid and 1.57 dB quieter than the other monitored. Based on this research, no evidence of beehive environment change in response to RM-EMR was found. At the same time, the observation of abnormally measured parameters could be linked with a stressed colony (due to a swanning event), which might help apiculturists reduce production losses by rapidly reacting to the observed indicators of potential stress. Given the complexity of beehive dynamics, research on other potential effects of RF-EMR is needed before adopting wireless technologies in beehive sensors.