Return of the lord Howe stick insect: A triumph over adversity
The incident with the SS Makambo ship, which occurred in 1918, led to an unforeseen ecological disaster. Rats that escaped from its deck onto Lord Howe Island rapidly dominated the local environment, eliminating species lacking natural predators. One of their victims was the stick insect Dryococelus australis, also known as the Lord Howe Island stick insect.
For decades, the stick insect was believed to become extinct around 1920. It wasn’t until 2001 that scientists, Dr. David Priddel and Dr. Nicholas Carlile, discovered a small population of this species during an expedition to Ball’s Pyramid—a rocky outcrop located in the Tasman Sea and distant from Lord Howe Island. It turned out that the insects survived in extreme conditions, benefiting from protection from rats, provided by their presence on the rock remote from the island, and the ability of females to reproduce without males (parthenogenesis), reports Earth service.
The world's rarest insect returns
In 2003, two individuals belonging to the Dryococelus australis species, named Adam and Eve, arrived at the Melbourne Zoo to initiate a breeding programme. After initial difficulties, they managed to breed them, which allowed the insects to be sent to other zoos worldwide. Their return to Lord Howe Island was also planned, but the key to the success of this project was the elimination of rats and mice living there.
Rodents reached the island after the SS Makambo ran aground in June 1918 near Neds Beach, at the northern tip of the island. The ship was relaunched after 9 days. The rats escaped from its deck and reached the land during this time. Black rats, a species found on all continents except Antarctica, quickly took over the island and affected its ecosystem. Their victims included numerous bird and insect species, including the aforementioned Dryococelus australis—currently considered the rarest insect in the world.
Only through a comprehensive eradication campaign in 2019 was the island "freed" from these pests. However—as noted by the Earth service—in 2021, there were a few cases of their presence, requiring additional measures. Today, thousands of Lord Howe Island stick insects are bred in captivity, ready to return to their original homeland. Biologists emphasise that restoring this species is an ecological success and an example of the importance of protecting fragile ecosystems from invasive species.
