Ancient Cicadas Evolved Flexible Long Proboscis to Feed on Thick-Barked Trees 100 Million Years Ago

Researchers have uncovered a remarkable evolutionary adaptation in cicadas from around 100 million years ago, preserved in amber across a vast region from eastern Russia to Europe and Lebanon. These ancient insects, belonging to the Neazoniidae family, possessed an unusually long and flexible proboscis, about twice their body length, unlike any of the 45,000 known modern cicada species. The study, published in MDPI Insects, reveals that this specialized mouthpart likely enabled them to access food sources unreachable by other insects, such as sugary sap from thick-barked trees.

Using advanced X-ray particle accelerator imaging in Hamburg, Germany, scientists visualized the internal structure of the proboscis at microscopic resolution. They found it covered with dense transverse wrinkles, providing flexibility and resistance to breaking, similar to a flexible plastic straw. The proboscis was also capable of bending in multiple directions, as evidenced by fossils preserved in amber while the insects were alive. This flexible design contrasts with modern cicadas' shorter, segmented proboscises adapted for feeding on plant surfaces.

The researchers, including Dolev Fabrikant from Tel Aviv University and Dr. Leonidas-Romanos Davranoglou from the Steinhardt Museum of Natural History, suggest that these ancient cicadas used their proboscis to pierce tree bark and extract nutrient-rich sap. Unlike butterflies, which have flexible proboscises for sipping nectar and often carry pollen, no pollen grains were found on these fossils, supporting the sap-feeding hypothesis. The proboscis tip had two rough lobes that likely helped anchor it to plant tissue for stable feeding.

This adaptation may have evolved due to ecological pressures in Cretaceous tropical forests, where frequent wildfires led to the prevalence of thick-barked trees. Such bark provides protection against fire, and the cicadas’ specialized mouthparts allowed them to exploit this niche. The study sheds light on an ancient evolutionary arms race between insects and plants, revealing how cicadas adapted to challenging environments long before flowering plants became widespread.

The ancient cicada was nicknamed "Nono" after a fictional vacuum-shaped character from the children's TV show Teletubbies, inspired by its distinctive long proboscis and large eyes. This discovery not only expands understanding of insect evolution but also highlights the complex interactions shaping ecosystems during the age of dinosaurs.