PMC

Two different liquid phases in bee-collected pollen adhesive. a Packed pollen grains (pollen pellet) on a pollen basket. Image is adapted with permission from Wikimedia Commons (photograph by Muhammad Mahdi Karim). SEM images of honey-bee-collected pollen grains (scale bar = 20 μm) (b) and a single dandelion pollen (scale bar = 10 μm) before (c) and after (d) solvent wash (water and toluene). e Optical microscope image of a bee pollen adhesive droplet on a silicon wafer (core region—blue box, surrounding region—red box). Scale bar = 60 μm. f Confocal Raman spectroscopy spectra of the surrounding (red) and the core (blue) regions of the droplet (488 nm laser excitation). g Confocal fluorescence microscopy images of a bee pollen adhesive droplet, top view with side view shown in a smaller in yellow box. Scale bar = 10 μm

The pink-coloured pollen grains of C. transsylvanica have been mass-packed in the pollen baskets located on the third pair of legs (red arrow). Scanning electron micrograph (external view) of a Cephalaria transsylvanica pollen mass packed in the pollen basket located on a leg of A. mellifera (B).

Bar = 1 mm. (B) Distal tarsal segments. Bar = 150 μm. (C) Detail of the structures involved in the grooming behavior and pollen collection. The pecten spines (arrow) and the pyramidal spines of the auricle (arrowhead) convey and pack the pollen into the pollen basket located on the outer surface of the leg. The pollen comb (pc), composed by transverse rows of stiff spines, brush off pollen from the lateral surface of the body and collect wax scales from the abdomen. Bar = 300 μm.

The life cycle of E. dilemma. Foraging individuals are shown with yellow pollen in their corbicula (tibial pollen basket). Arrows represent sequential stages of behaviour. The blue box shows which behaviours were sampled in this study. Euglossa image adapted from []. (Online version in colour.)