It was not the fly itself that caught the scientists’ attention, but its swollen stomach indicates that it was still full of the fly’s last food. Surprisingly, the analysis of the stomach’s content showed that it was filled with pollen from different plants. Fossil pollen from the fly’s stomach was used to reconstruct the ancient environment inhabited by the fly, the biological interactions between the plant and the fly, and the behavior of the fly during feeding.
Flies as pollinators
Today, bees, butterflies and bumblebees are typical pollinators, which have also been known to feed on pollen. It has rarely been reported that flies play an important role in pollination. Says Fridgeir Grímsson from the Department of Botany and Biodiversity Research at the University of Vienna. The scientist concludes that “flies were among the main pollinators in ancient parabolic (subtropical) ecosystems and may have outperformed bees.”
Short-haul flights for catering
The extracted pollen was dominated by Decodon (Waterwillow) and Parthenocissus (Virgin Ivy) grains. Today, the aquatic tree is a sub-shrub that grows in wetlands and shallow lakes, indicating open, low-domed habitats. The common dominance of virgin ivy also indicates that the fly feeds on plants growing at the edge of the forest surrounding ancient Lake Messel. “It is possible that the fly avoided long flights between food sources and sought to obtain pollen from closely related plants,” says Grimson.
Posted in Current biology:
S. Wedmann, T. Hörnschemeyer, MS Engel, R. Zetter, F. Grímsson. The last meal of the eosin fly that feeds on pollen. Current biology (2021)
DOI: 10.1016 / j.cub.2021.02.025