How a tiny fly survives the lethal trap of the La Brea Tar Pits
In the sticky, black asphalt of Los Angeles, life seems impossible. Most creatures are doomed the moment they touch the ooze. Yet, the petroleum fly has mastered this toxic landscape, using the very substance that traps its prey to sustain its own fragile existence.
The La Brea Tar Pits are a site of immense paleontological importance, containing fossils from the Ice Age era, roughly between 50,000 and 40,000 years ago. While many mistakenly believe these pits hold dinosaur remains, the dinosaurs actually went extinct about 65 million years before these asphalt seeps began to form. Instead, the pits preserve the bones of prehistoric giants like mammoths, saber-toothed cats, and dire wolves.
Amidst these fossils lives the petroleum fly. The adult flies possess a remarkable, though precarious, ability to navigate the surface; they can walk and mate on the natural asphalt without becoming stuck. However, this skill is highly specific. If any other part of their body contacts the tar, they perish. The mystery of exactly how they maintain this precision remains a subject of scientific interest.
The larvae of the fly operate under a different set of biological rules. Unlike most insects that use a waxy exterior to prevent dehydration, the petroleum fly larvae have an extremely thin exterior. Without the asphalt, they would simply dry out. Consequently, they thrive by fully submerging themselves in the viscous dark liquid, hunting small insects trapped within it. This lifestyle is so integrated with their environment that their guts are often visible through the asphalt they ingest. While this consumption is vital for their survival, it is a process humans could not replicate, as ingesting such amounts of asphalt poses a cancer risk.
Source: How Can These Flies Live in Oily Black Tar Pits? | Deep Look
