Morphology and Elemental Composition of Metal Based Granules in Wings of Bumblebees

The paper addresses detection and elemental analysis of solid metal-based particles/clusters present in wings of laboratory bread bumblebees. The goal of the article is detection and characterization of morphology and chemical composition of those particles. A combination of Gallium Focused Ion Beam (FIB)—Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) mapping were used for evaluation of particles/clusters localization in the samples. FIB allowed etching of subsurface structures and deeper understanding of particles/clusters structure. EDS mapping revealed distribution of single elements in detected particles/clusters. It was found that all evaluated particles/clusters were based on iron or iron oxides and were associated with calcium structures. Several other elements such as Al, Mg, Ti, Zn or Si were also detected. Several hypotheses for role of the detected particles were introduced, however the real purpose was not revealed.