How far would you be prepared to walk to pick up some groceries?
For even the most committed bipeds, I suspect it’s not as far as euglossine bees (or ‘orchid bees’) travel to visit their favourite flowers. It has been suggested that these extraordinary bees, featured on the cover of New Phytologist 213:4, can travel more than 20 km in one foraging trip.
The cover image shows a female euglossine bee hovering in front of a blossom inflorescence of Dalechampia scandens, a vine in the spurge family (Euphorbiaceae). Female bees collect resins from this plant for use in nest construction, and some whitish resin can be seen already collected on the bee’s hind corbiculae (hind legs).
Populations of Dalechampia vines, from which female euglossines collect resin, can be small and patchy, so the bees may have to fly long distances to make regular visits to specific plants – a behaviour known as ‘traplining’.
Traplining bees are thought to contribute to long-distance gene flow between isolated populations of tropical plants. In their paper, Øystein Opedal and colleagues tested this hypothesis by investigating gene flow and genetic structure in Dalechampia scandens.
The researchers found that, while some recent gene flow might have occurred under specific conditions, gene flow overall is very limited. Despite their commitment to long-distance foraging, the role of euglossine bees in long-distance gene transfer remains something of a mystery. More information about different plant species, and the foraging habits of males, which might fly further than females and aren’t bound to a particular nest, is needed.
You can find more information about this paper and Øystein’s research on his blog: ‘Plants in a changing world’.
Read the paper: Opedal, Ø. H., Falahati-Anbaran, M., Albertsen, E., Armbruster, W. S., Pérez-Barrales, R., Stenøien, H. K. and Pélabon, C. (2016) Euglossine bees mediate only limited long-distance gene flow in a tropical vine. New Phytologist. doi: 10.1111/nph.14380
What to read next:
- The evolution of plant evo-devo research
- 3-D printed flowers provide insights into how orchids attract pollinators