Researchers recently uncovered the role of clay towers built by young Amazonian cicadas, specifically Guyalna chlorogena. These clay structures serve as protective shelters during their final underground development stage. This discovery sheds light on a long-standing mystery about cicada behavior, revealing how these towers are key to their survival.
The Discovery
Located near Manaus, Brazil, these clay towers create a unique environment for the cicadas. The research team from the Serrapilheira Institute studied how these structures affect airflow and predator interactions. They found that when airflow is blocked, cicadas displayed surprising behaviors, indicating that the towers are not just random dirt but crucial for their survival.
Predator Protection
In experiments, researchers placed bait on the towers and the surrounding ground. It became clear that fewer ants were present on the towers. Marina Méga, a doctoral student in ecology, noted, “There were eight times fewer ants on the towers than on the ground.” This height advantage seems to protect the cicadas just when they need it most, especially during metamorphosis when they can’t dig back into the earth.
Testing Airflow
To understand airflow, the team sealed the tower tops with latex, cutting off fresh air. This created a stressful environment for the cicadas inside. Results showed different rebuilding responses when the seals were removed, indicating that the cicadas rely heavily on these towers for respiratory needs.
Size Matters
Interestingly, not all towers are the same size, and larger towers responded better during airflow tests. Bigger structures provided more space, allowing for better air circulation. This finding explains the size variability of these towers, as larger structures can better buffer environmental stress.
Redefining Nature
The concept of the tower as an “extended phenotype” has significant implications. It means that the cicada is utilizing its environment to aid its development. By transforming mud into a protective tool, these creatures are essentially shaping their surroundings to enhance their chances of survival.
A Look Back
Past studies also hinted at the towers’ protective role, showing each cicada rebuilds its tower night after night. Changes in the environment influence how these towers operate, reinforcing the idea that they are responsive structures.
Balancing Risks
Approaching adulthood, cicadas must leave their underground homes. This exposed phase is risky, as ants can easily harm them. The towers offer a crucial advantage by elevating the cicadas above ground level, reducing the chance of predation.
Practical Research
Conducting this research in the heart of the Amazon required creativity. The team, using simple methods, demonstrated how innovative solutions often arise from challenging environments. The use of everyday items like condoms to seal airflow exemplifies this practicality in fieldwork.
Remaining Questions
While the study answers many questions, it raises new ones. For example, how do different tower heights affect cicadas differently? The variations hint at complex interactions between soil, moisture, and cicada behavior.
Why It Matters
This research provides valuable insights into how these small insects engineer their survival. As scientists continue to explore these relationships, we may uncover more about how environment and biology intertwine. The study was published in Biotropica, paving the way for further investigations into these fascinating creatures.
In summary, the journey of cicadas from nymphs to adults is a dance of engineering and adaptation. Observing their unique strategies teaches us about resilience in nature.
