In July of this year, Nathan Lo from Sydney University organised a joint study to be undertaken on the Lord Howe Island wood-eating cockroach. The three partners in the study are the University of Sydney, the NSW Department of Environment and the Lord Howe Island Museum.
The Lord Howe Island cockroach Panesthia lata is one of eleven species in the genus that occur along the east coast of Australia from Northern Australia to Victoria. This particular species is endemic to Lord Howe Island.
Examples of the species were reported and collected by all of the early natural history expeditions to the island; but when the rats arrived in 1918 the cockroaches soon disappeared off the main island. However, they were surviving on the offshore islands of Blackburn, Roach and Balls Pyramid that were all rat free.
The three offshore islets where the cockroach was known to have survived
With the eradication of rats from Lord Howe Island in 2019 there began talk of translocating a number of endemic insects from offshore islands back on to the main Lord Howe Island. These will include the stick insect known as the phasmid that was found in 1964 on Balls Pyramid by rock climber David Roots and a number of flightless beetles found on Blackburn Island in 2018 by a Citizen Science program run by the Australian and Lord Howe Island Museums.
Nathan Lo’s project is investigating the DNA of the existing populations of the Lord Howe Island cockroach and comparing that with the DNA of the old specimen collections from the main island that are held by the Australian Museum. His aim is to be able to select the closest extant population of cockroaches to translocate back to the main island.
In July 2022, some of the team were waiting for weather to calm down so they could access offshore islets. While waiting, they made a search of some sites on the main island that had a similar habitat to where the cockroach population is living on Blackburn Island.
To their surprise, cockroaches were found living under small boulders at North Bay. Initial DNA studies show they are slightly different to the Blackburn Island population, but further work is being carried out.
References
Crikey! A large roach believed extinct since the 1930s has been rediscovered on Lord Howe Island.
Nathan Lo, Australian Geographic, 7th October, 2022
‘Extinct’ wood-eating cockroach rediscovered after 80 years.
Wilson da Silva, University of Sydney News, 1st October, 2022
