Spatial Distributions of Inorganic Elements in Honeybees (Apis mellifera L.) and Possible Relationships to Dietary Habits and Surrounding Environmental Pollutants

In this study, the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was adopted to determine the distribution of inorganic elements, including Ca, Cu, Fe, Mg, Mn, S, P, Pb, and Zn, in honeybees (Apis melifera L.). Two features are particularly noteworthy. First, it was found there is a significant amount of Fe located at the fringe of the abdomen in worker bees; ultrasonic imaging, scanning electron microscopy, and magnetic resonance imaging revealed that it arose from magnetic Fe-bearing nanoparticles (NPs) having an average diameter of approximately 40 nm. Interestingly, only worker bees contained these magnetic Fe-bearing NPs; no similar features appeared in larvae, pupae, wasps, or drones. Second, a detectable amount of Pb accumulated particularly in the alimentary canals of worker bees. Again, no detectable amounts of Pb in larvae, pupae, drones, or wasps, yet a level of 0.24 +/- 0.05 mg/kg of Pb in pollen; therefore, the diet appears to be the primary pathway for environmental pollutants entering the honeybees' food chain.