Rediscovered thanks to citizen science: cicada found again after 100 years

As National Geographic reported, the cicada species Okanagana arctostaphylae has been rediscovered more than a century after it was last seen. The discovery was made by nature observer Lucinda Collings Parker in her garden in the foothills of the Sierra Nevada in California.

Parker photographed the striking red cicada in July 2020 and uploaded the image to iNaturalist, an online citizen science platform for studying and documenting biodiversity. There it was noticed by entomologist Will Chatfield-Taylor of the University of Kansas, who forwarded it to cicada experts Jeff Cole and Elliott Smeds, scientific staff members at the Natural History Museum of Los Angeles County and the California Academy of Sciences respectively. All three quickly agreed: this was Okanagana arctostaphylae, a species missing since 1915.

Searching for the lost species

Shortly afterward, Smeds set out to track down the rediscovered cicada species in the wild. Driving with the windows down, Smeds searched the western slopes of California’s Sierra Nevada in the hope of hearing the cicadas’ characteristic call. Based on his knowledge of related species, he had an idea of what Okanagana arctostaphylae might sound like.

Already the next day, Smeds came across the roughly 3.8-centimeter-long red cicadas. They were sitting on the equally red stems of their host plants, the manzanita shrubs and trees. A few weeks later, the cicadas disappeared again. But thanks to Smeds’ discovery, the researchers now knew where and when they had to search. In 2023, the cicadas were finally sighted again.

Further observations and searches, some of them using the iNaturalist platform, showed that Okanagana arctostaphylae occurs across a larger area west of the Sierra Nevada foothills in California than initially assumed. The span between the northernmost and southernmost observations is more than 200 kilometers. The long period without records can be explained by the fact that the cicadas spend most of their lives – up to 17 years – underground. Adult animals emerge only for a short time during high temperatures and in dense vegetation.

Cicadas west of the Rocky Mountains are barely studied

Until now, little was known about the lifestyle and range of Okanagana arctostaphylae. Thanks to the rediscovery, researchers can now learn more about these insects. One important aspect is the great species diversity west of the Rocky Mountains. Compared with the eastern cicada species, the western species are much less studied. Some species have been recorded for the first time in generations – and Okanagana arctostaphylae is the prime example.

Like aphids and true bugs, cicadas possess a kind of straw that they insert into plants in order to suck up liquid food in the form of sap. This has proven a successful strategy, because there are more than 3,000 cicada species worldwide. Cicadas are also characterized by a two-part life cycle: they spend most of their lives as nymphs underground, where they live on root sap. After a species-dependent period of 1 to 17 years, they dig themselves out, molt and transform from brown, bean-shaped creatures into winged insects – the loudest in the world.

Life cycles of western cicadas remain mysterious

In contrast to the eastern cicadas, whose appearances can be predicted decades in advance, the life cycles of western cicadas remain mysterious. Neither their ranges nor the timing of their emergence are known precisely.

Many western cicada species show protoperiodical life cycles. This means that some individuals appear every year, but at irregular intervals there are mass emergences. Compared with the periodical cicadas of the East, however, these swarms are less strongly pronounced.

The exact trigger for the appearance of protoperiodical cicadas in the West is still unclear, but rain seems to play an important role. Studies show that major swarms appeared only after years with above-average precipitation.

Citizen science provides support for cicada research

California alone is home to around 80 recognized species in the species-rich cicada family. However, there are only a handful of entomologists who focus on western cicadas. Cicadas are relatively poorly studied because their long life cycles and sporadic appearances are difficult for scientists to study. Experts can rarely wait years until the organisms they want to investigate appear above ground, and they cannot be everywhere at once. These characteristics make observation and research challenging for scientists, and it is reasonable to assume that many undiscovered cicada species still exist in the western United States.

The possibilities offered by citizen science provide new approaches for cicada research. Platforms such as iNaturalist make it possible for nature lovers around the world to share their observations and thus collect valuable data. In 2023, for instance, photos helped rediscover six new species of carnivorous plants on social media.

The rediscovery of the cicada species Okanagana arctostaphylae illustrates the potential of citizen science. Through the observation and documentation of a nature enthusiast, this species was rediscovered after more than 100 years. The combination of professional research and the commitment of amateur researchers and nature photographers can advance cicada research in the western United States.