Rediscovery of the 'Extinct' Wood-Eating Cockroach After 80 Years
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Chapter 1: The Rediscovery of a Unique Insect
The wood-eating cockroach, once believed to be extinct, has been found once again on Lord Howe Island, Australia. This large, wingless insect, which disappeared from sight since the 1930s, was located by a biology student from the University of Sydney.
“For the first 10 seconds or so, I thought ‘No, it can’t be’,” remarked Maxim Adams, an Honours student working under Professor Nathan Lo at the School of Life and Environmental Sciences. “I lifted the first rock under this enormous banyan tree, and there it was.”
“We discovered multiple families of these cockroaches all residing under that single banyan,” explained Nicholas Carlile, a Senior Scientist at the New South Wales Department of Planning and Environment (DPE), who accompanied Adams on this expedition to North Bay, a remote beach accessible only by foot or water. “In fact, Maxim and Nathan spent the rest of the week examining other banyans in North Bay but didn’t find any more.”
Section 1.1: A Glimpse into History
The Lord Howe Island wood-feeding cockroach (Panesthia lata), previously abundant on the island, was presumed extinct due to the arrival of rats in 1918. Although some closely related species were found on smaller nearby islands, the rediscovered cockroach population is genetically distinct.
“The discovery is fantastic news, as it had been over 80 years since anyone had last seen it,” stated Lord Howe Island Board Chair Atticus Fleming about the finding first made in July 2022. “Lord Howe Island is truly extraordinary; it’s older than the Galápagos Islands and is home to 1,600 native invertebrate species, half of which exist nowhere else on the planet.”
“These cockroaches are somewhat akin to our own version of Darwin’s finches, having evolved unique genetics over thousands or millions of years on isolated islands,” he added.
Subsection 1.1.1: The Ecological Role of Cockroaches
Though they may not appear endearing, these cockroaches play a vital role in the island's ecosystem. They help recycle nutrients, assist in breaking down decaying logs, and serve as a food source for other species. Scientists had previously considered reintroducing these insects from offshore islands, but now, with their rediscovery, such measures are no longer necessary.
“There remains much to learn,” remarked Lo, the head of the Molecular Ecology, Evolution, and Phylogenetics (MEEP) Lab. “We aim to investigate their habitat, behaviors, and genetics to understand how they managed to survive, through further research on the island.”
Section 1.2: Characteristics of the Cockroach
The wingless cockroach measures between 22 and 40 mm in length, displaying a metallic color that ranges from reddish to black. Australia is home to 11 Panesthia wood cockroach species, which are adept burrowers that inhabit and feed on decaying logs found in rainforests and coastal forests in northern and eastern Australia.
These cockroaches harbor specialized microorganisms in their guts that aid in digesting cellulose from wood. Female cockroaches give birth to nymphs that remain in family groups alongside adults. However, the unique behavior of this species may have led to a misclassification.
“Despite their name suggesting they feed on wood and burrow in rotting logs, we now believe they are more akin to ‘rock-roaches,’ as rocks play a significant role in their habitat, possibly due to their co-evolution with the ground-foraging Lord Howe Island Woodhen,” Carlile explained, recalling the rediscovery of the Lord Howe Island Stick Insect in 2001 on Ball’s Pyramid.
Chapter 2: The Importance of Preservation
The video titled "Extinct Wood-Eating Cockroach Rediscovered After 80 Years" provides insights into the significant find on Lord Howe Island and underscores the importance of conservation efforts for unique species.