Oxford Brookes researchers discover new species in Australia

Researchers at Oxford Brookes University have identified a tiny new predator, a feather-legged assassin bug measuring just two millimetres long.

Though small in size, the insect is offering big clues about evolutionary change among its relatives.

Named Aratrichous anacomosus, the insect has been nicknamed the ‘pineapple assassin’ because of a small, pineapple-shaped gland on its body.

It was discovered in South Australia, with another specimen found in Pibara, Western Australia.

Dr Matthew Bulbert, senior lecturer in conservation ecology at Oxford Brookes, said: “This one really surprised us.

“It’s incredibly tiny, and it’s lost some of the features that usually define feather-legged assassin bugs.”

Feather-legged assassin bugs are known for their feathery limbs and ant-hunting behaviour, but this new species differs significantly from its relatives.

The bug has lost many of its signature feather-like hairs, a result of extreme miniaturisation, while its antennae have become larger and more specialised.

Researchers believe these adaptations may help the insect chemically mimic ants in order to live among them.

Despite its tiny size, the ‘pineapple assassin’ retains the gland thought to attract or manipulate ants.

Until now, this feature was believed to be absent in this branch of feather-legged assassin bugs.

Daniel Bardey, the PhD student who discovered the new bug, said: “That’s what makes this species so exciting.

“It appears to be a transitional form that shows how features like this gland were lost and gained during the evolutionary history of these insects.”

The bug’s distribution also surprised scientists.

Specimens were found thousands of kilometres apart in central Australia, despite the species’ inability to fly and its limited movement.

Dr Bulbert said: “Understanding where these species occur is important for conservation, because animals that cannot move far are especially vulnerable if their habitats are disturbed.”

Researchers also found that both male and female bugs have reduced wings, an unusual trait not previously observed in Australian members of this group.

Feather-legged assassin bugs represent one of the oldest lineages of assassin bugs.

Their ancestors are believed to have arrived in Australia long ago and evolved into specialised species found nowhere else on the planet.

The discovery suggests unexpected evolutionary changes.

Dr Bulbert said: “It’s incredibly tiny, and it’s lost some of the features that usually define feather-legged assassin bugs.”

The findings are detailed in the paper ‘Phylogenomics shows loss of myrmecophagous traits in Holoptilinae and necessitates synonymisation of feather-legged assassin bug tribes (Hemiptera: Reduviidae)’ published in the Journal of Systematics and Biodiversity.