Researchers in Australia have identified two new species of giant stick insect and resurrected a third that had been misclassified for decades — and one of the new finds lays eggs unlike any recorded before in the insect order.
The work, led by Dr. Braxton Jones of the University of Sydney's Aola Richards Sydney Insect Hub and published in the journal Austral Entomology, revised the genus Anchiale by combing through decades of museum specimens alongside freshly collected insects. What scientists had long treated as one or two species turned out to be five, stretching from northern New South Wales through coastal Queensland into the tropics.
The most striking of the group is the newly described Anchiale mabiensis, found only in the Mabi rainforest of Queensland's Atherton Tablelands — one of the country's most fragmented and endangered rainforest types. Females of the species stretch to roughly 16 centimetres. Their eggs, researchers found, carry a ringed, lid-like structure that detaches when the nymph hatches, a feature Smithsonian magazine reported has not previously been documented in stick insects or any related order.
Taxonomy is often a bit like detective work. Even among some of Australia's most photographed and frequently reported insects, we're still finding species that have escaped scientific recognition.
— Dr. Braxton Jones, University of Sydney
The third species in the revision, Anchiale robusta, had effectively been hiding in plain sight: large, well-photographed insects long assumed to belong to a single widespread species turned out, on close anatomical comparison, to be a separate one that had gone unrecognized since it was first collected. Sorting the group required Jones's team to examine genitalia, egg structure and subtle body proportions across dozens of specimens, some of them more than a century old, held in Australian museum collections.
Because Anchiale mabiensis is known only from the Mabi rainforest — a habitat reduced to a fraction of its original extent by past land clearing — its formal description also gives conservationists a named, documentable species to factor into habitat protection decisions, something that is far harder to do for a population lumped in with a more common relative. Jones's team says further fieldwork is needed to confirm how widely the species actually ranges and whether its unusual egg lid serves a specific function, such as protecting against parasites or helping regulate moisture, questions the next phase of research aims to test directly in the field.
