Which critically endangered insect is locally known as the tree lobster?

The critically endangered insect locally known as the tree lobster is the Lord Howe Island stick insect.

Its scientific name is Dryococelus australis, and it is also called the Lord Howe Island phasmid. The species is native to the Lord Howe Island Group, east of Australia, and is the only member of the genus Dryococelus.

The insect was thought extinct after black rats reached Lord Howe Island following a 1918 shipwreck. No living specimens were found there after 1920, but a tiny remnant population survived on Ball’s Pyramid, a steep sea stack about 23 kilometres away. Scientists rediscovered living insects there in 2001; only 24 individuals were initially documented.

The tree lobster is unusual among stick insects because males and females can form pair bonds, and females can reproduce parthenogenetically when males are unavailable. Conservation breeding has helped establish captive populations, although restoring the species to Lord Howe Island remains difficult because introduced rats must be controlled.