Two giant Australian stick insects turned out to be five, and one lays eggs with a lid

University of Sydney entomologists have reworked the classification of Australia’s giant Anchiale stick insects, and a group long treated as two species now stands at five. The revision, led by Dr Braxton Jones and published in the journal Austral Entomology in September 2026, describes two new species, Anchiale robusta and Anchiale mabiensis, and restores a third, Anchiale albopunctata. It also leans on more than 1,000 public sightings logged by citizen scientists.

The most unusual find is on the egg of A. mabiensis, which carries a lid marked with rings that researchers say no stick insect has been recorded with before. The rest of the group is no less striking, since these are hand-sized insects that pass for twigs, and the revision shows how many of them were hiding behind two familiar names.

Anchiale species: how two became five

The paper, titled “A Revision of Australian Anchiale Stål, 1875 (Phasmida: Phasmatidae), with the Description of Two New Species,” appeared in Austral Entomology, volume 65, issue 4. Jones is joined by Paul D. Brock, Ross M. Coupland, Angus Emmott and Nathan Lo. Science News gives its publication date as 21 September 2026, and the university issued its own release the following day.

The five Australian species are now Anchiale briareus, Anchiale austrotessulata, Anchiale albopunctata, Anchiale robusta and Anchiale mabiensis. Reporting on the paper says A. albopunctata had been merged into A. briareus for more than a century, and A. austrotessulata carries a 2007 name from Brock and Hasenpusch, which points to those two as the pair recognised before this revision. The paper’s own species-level author citations were not available to this reporting, so none are given here for the new names beyond the paper’s authorship by Jones and colleagues.

The evidence was a mix rather than a single test. According to the University of Sydney release carried by ScienceDaily, the team combined DNA analysis with museum specimens, field surveys, citizen-science records and studies of captive-raised insects. Coverage of the work adds that A. robusta, which is larger than its relative A. briareus, was supported as separate by genetic analysis together with close inspection of its physical features.

A. robusta is the quiet embarrassment of the story. It had been photographed and collected many times, and ScienceAlert reports that records of it were being filed under another name as far back as 1976.

The egg lid of Anchiale mabiensis

Eggs are where A. mabiensis gives itself away. They are a duller, coffee-brown colour and less glossy and elongated than those of other Australian Anchiale, and the lid, the cap that opens when the nymph hatches, has two to three rings on it. Science News quotes the authors saying this is the first time such rings have been recorded in stick insects, and the Sydney release describes the lid as unlike anything previously documented in stick insects or their closest relatives.

The sources do not use the technical term for the structure, so the plain word lid is used here. Eggs of A. robusta, by contrast, are a darker brown and very glossy when laid, turning bumpier and matte over time until they look ashy.

Jones frames the discovery as slow, patient sleuthing. “Taxonomy is often a bit like detective work,” he said, and he added that scientists are still finding species that have escaped recognition. The citizen-science sightings, uploaded to iNaturalist and the Atlas of Living Australia, helped show where each lineage lives, from northern New South Wales along coastal Queensland into tropical northern Australia.

Mabi rainforest remnants and the Anchiale split

A. mabiensis appears to be confined to the Mabi rainforest of Queensland’s Atherton Tablelands, a forest type listed as critically endangered. ScienceAlert notes that only about 1,050 hectares remained as of 2021, in small patches within farmland that grazing, feral animals and invasive plants can reach from every side. A species known from one such remnant has little margin, though none of the coverage reports a formal conservation rating for A. mabiensis itself.

Jones tied the result to habitat protection directly. “These findings demonstrate the importance of protecting threatened ecosystems,” he said in the university release, and he stressed the value of documenting Australia’s biodiversity before species vanish undiscovered.

There is a practical side too. Anchiale briareus is known for outbreaks that strip foliage from trees, sometimes at plague-like numbers, and the Sydney release says separating it from look-alikes may help land managers judge impacts on forestry and agriculture. The team also flags a possible further species from Cape York that needs more specimens before it can be confirmed, so the count may not be final. For now, the revision turns a loosely understood pair of names into five distinct animals, each of which can be tracked, protected or managed on its own terms.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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