Ecologists Eradicated Insects on Florida Keys Islands to Test Species Recolonisation

In 1966, researchers sealed tiny mangrove islands in the Florida Keys under plastic tents and fumigated them, wiping out almost all arthropods to observe how wildlife recolonises empty habitats.

Ecologists Daniel Simberloff and Edward O. Wilson transformed several small mangrove islands in the Florida Keys into controlled laboratories in 1966. They enclosed each island in a large plastic canopy and used methyl bromide to eliminate nearly all terrestrial arthropods while leaving the vegetation intact. Over the following months they documented the arrival of new insects, spiders and other invertebrates, noting that colonisation occurred far more quickly than anticipated.

The assemblages that developed resembled the pre-experiment communities, illustrating that species immigration and extinction reach a stable balance, a concept later termed faunistic equilibrium. The results offered one of the first direct tests of the Theory of Island Biogeography, confirming that island size and isolation shape species richness. Decades later, the experiment continues to inform conservation practices for fragmented habitats worldwide, emphasizing the importance of connectivity for ecosystem recovery.