Hyperspectral lidar for monitoring high-resolution activity patterns of African stingless bee species

Abstract

Abstract Background Stingless bees are vital pollinators and honey producers in the tropics. Research on stingless bees is generally underrepresented compared to the western honeybees, and while stingless bee studies from some regions are reported, there is a particular lack of reports on the species endemic to Sub-Saharan Africa. Since conventional entomological methods such as mark-recapture and radar harmonic tags suffer from limited observation counts and amount to a significant payload, fluorescent powder tagging offers a promising alternative to understanding their behavior. We deploy a hyperspectral fluorescence lidar monitors a 25-mm-wide transect in front of the hives. Results During a 1 day study at the International Stingless Bee Center, near Kakum National Park, Ghana, 17,862 insects were observed with the lidar, of which 7520 were tagged with fluorescent dyes. Approximately half of the bees from the selected hives were successfully tagged, with an estimated misclassification of 1%. According to our limited data, the observed species, Meliponula bocandei and the Dactylurina staudingeri exhibited different activity patterns. D. staudingeri displayed a half-hour longer active day, with clear crepuscular activity peaks. In contrast, M. bocandei activity was diurnal, with less pronounced crepuscular peaks. Conclusions We demonstrate how hyperspectral fluorescence lidar can monitor powder-tagged insects throughout the day. The monitored species revealed distinct activity patterns over the day. Our findings highlight the potential of this technology as a valuable tool for understanding insect behavior and environmental preferences of species, in situ, which could potentially give clues of response to climate changes of these critical species.