Stingless bee (Apidae: Meliponini) foraging and predation at trunk resin sources: Rare observations captured with microcontroller-based camera traps in a lowland dipterocarp forest
An intriguing yet little studied aspect of social insect foraging is the use of resources other than food. We are interested in the collection of plant resins for nest construction and defense by tropical stingless bees. However, direct observations of stingless bee foraging and potential predation activities by natural enemies at resin sources are particularly rare and therefore require a trade-off between observation time and the number of sources observed. We used affordable remote microcontroller-based camera traps to enable for longer durations of continuous and simultaneous monitoring of resin foraging at multiple resin sources in an undisturbed lowland dipterocarp rainforest in Brunei Darussalam (Borneo). Analysis of photos from camera traps shows that stingless bee visitation to resin sources was uncommon at resin wounds in the forest understory (27.3%). Bees visiting wounds displayed a propensity for short and regular resin foraging bouts of up to a few days to particular resin sources. Where there were encounters between stingless bees and natural enemies, i.e., assassin bugs at resin sources, there was a 100% predation success rate (n = 4). Our study suggests that microcontroller-based camera traps complement or may even replace in-person field observations, in particular for observations of organisms or interactions occurring at low abundance. They allow for systemically collected observations which can form the basis for hypothesis-driven research as part of “next-generation natural history”.