An ‘extinct’ carnivorous cockroach reappears after 90 years

Sep. 30 () –

A large, wingless, carnivorous cockroach, unique to Australia’s Lord Howe Island and thought to be extinct since the 1930s, has been rediscovered by a Biology student.

“For the first 10 seconds or so, I thought ‘No, it can not be’said Maxim Adams, an honors student of Professor Nathan Lo at the University of Sydney’s School of Biological Sciences. “I mean, I lifted the first stone under this huge banyan tree, and there it was.”

“We found families of them, all under this banyan tree,” said lead scientist Nicholas Carlile of the New South Wales Department of Planning and Environment (DPE), who was with Adams exploring North Bay, an isolated white-sand beach off that can only be accessed on foot or by water. “Actually, Maxim and Nathan were there the rest of the week, They looked under all the other banyan trees in North Bay, but found nothing.”

Lord Howe Island’s unique wood-eating cockroach (Panesthia lata), which once ranged throughout the archipelago, was thought to have become extinct following the arrival of rats on the island in 1918. During the next decades, searches uncovered scattered populations of close relatives on two small offshore islands. But the rediscovered group is genetically different from those, reports Eureka Alert.

“Survival is great news as it has been over 80 years since it was last seen,” Lord Howe Island Board Chairman Atticus Fleming said of the find, first made in July. 2022. “Lord Howe Island is truly a spectacular place, it is older than the Galapagos Islands and is home to 1,600 native species of invertebrates, half of which are found nowhere else in the world.

“These cockroaches are almost like our own version of Darwin’s finches, separated on small islands over thousands or millions of years, developing your own unique genetics“, he added.

They may not be cute or cuddly, but cockroaches are the cornerstone of maintaining a healthy ecosystem on the island, since they act as important nutrient recyclers, important to accelerate the decomposition of the trunks and as a food source for other species. That’s why scientists had been exploring the feasibility of reintroducing them to the main island from offshore islets. Now they don’t have to.

“There is still a lot to learn,” said Professor Lo, head of the Molecular Ecology, Evolution and Phylogenetics (MEEP) Laboratory in the School of Life and Environmental Sciences. “We hope to study their habitat, behavior and genetics, and learn more about how they managed to survive, through more experiments on the island.”

The wingless cockroach is between 22 and 40 mm long, with a metallic body color that varies from reddish to black. Australia is home to 11 species of Panesthia wood cockroaches, powerful burrowers that live inland and feed on rotting logs in rainforest and open woodlands on Australia’s north and east coast.

They carry specialized microorganisms in their guts that help digest the cellulose in the wood. The females give birth to nymphs that remain in family groups with the adults.. But unique arthropods behave differently and may have been misnamed.