A nondescript orchid, Cypripedium wardii, goes about its business inside a lush forest in Sichuan province, China. Nearby, a bee flies about, seeking its next pollen meal. Eons of evolutionary time allowed orchids like C. wardii to fool these tiny pollinators by evolving its own “counterfeit” pollen—pseudopollen, if you will—to try and trick the tiny insect into aiding its own reproduction. After all, it doesn’t produce nectar, nor does it produce some distinct floral fragrance that can otherwise attract pollinators such as the nearby bee. Instead, the orchid tries to fool the bee by employing pseudopollen that’s indistinguishable from the real thing. Some orchids create these pollen fragments with barely any nutrients at all; others give a little more by creating pseudopollen containing lipids, proteins, and carbohydrates. The nearby bee, none the wiser, approached the orchid and dined on these counterfeit pollen particles, then went on in its merry life without much of a second thought.
The thing is, up until recently, scientists weren’t exactly sure if these bees even get any nutrition from these pseudopollen particles at all, and the orchids were really just good at pulling a fast one on them. A recent study by researchers from the Chinese Academy of Sciences, viewable on bioRxiv, argues that the orchids don’t just try to fool these bees by letting them eat their pseudopollen; the bees actually get nutrition out of these counterfeits, too.
In the study, the researchers observed 12 species of bee and hoverfly that collected pseudopollen from C. wardii orchids. They then collected some specimens of these insects, and brought them back to the lab for dissection. In doing so, they discovered the pseudopollen particles inside the insects’ digestive tracts, with analysis of the pseudopollen showing the presence of lipids; the bees were actually being fed by eating the orchids’ counterfeit pollen. According to co-author Yi-Bo Luo, this is the first time they’ve confirmed that pseudopollen from these orchids are actually real rewards for the pollinators. Rodrigo Singer, an orchid pollination specialist at the Federal University of Rio Grande do Sul, is also convinced that these bees and hoverflies aren’t actually being fooled at all, and that they can actually sense the nutritional value of these pseudopollen produced by C. wardii, hence why they’re eating them.
Kevin Davies, a botanist at Cardiff University who’s uninvolved with the study, is convinced that the work is a “step forward” for the field, seeing as it’s the first time scientists have been able to show that these pseudopollen isn’t just “fool’s gold” for these insects. Davies hopes that these results will encourage further studies into the pseudopollen produced by other orchids, to see which other “counterfeit” pollen are actually edible for insect pollinators.
Bibliography
- Pallardy, R. (2021, May 12). Bees and hoverflies gobble fake pollen, benefiting both insect and plant. Science. Retrieved August 17, 2021, from https://www.sciencemag.org/news/2021/05/bees-and-hoverflies-gobble-fake-pollen-benefiting-both-insect-and-plant
- Zheng, C.-C., Luo, Y.-B., Gao, Y.-D., Bernhardt, P., Li, S.-Q., Xu, B., & Gao, X.-F. (2021, April 11). Cypripedium wardii (Orchidaceae) employs pseudopollen with both reward and deception to attract both flis and bees as pollinators. bioRxiv. https://doi.org/10.1101/2021.04.11.439382
