Australian researchers have identified two new species of large stick insects in far north Queensland, shedding light on the region’s underexplored insect diversity and altering previous understandings of the group’s taxonomy. The findings, published in Austral Entomology, underscore the challenges of insect identification and highlight important conservation considerations.

One of the newly described species, Anchiale robusta, had been mistaken for another species for decades despite being well-known to both scientists and insect enthusiasts. Researchers, led by Dr. Braxton Jones of the University of Sydney, initially suspected a more complex taxonomy when they observed individuals with differing physical characteristics occupying distinct habitats. Through a combination of DNA analysis, museum specimen review, citizen science data, and field surveys, the team confirmed the misidentification.

Female Anchiale robusta specimens measure between 12 and 16 centimeters in length, while males are smaller, ranging from 9 to 10 centimeters. Their wings are predominantly black, with some displaying purple hues on the underside of the hindwings. Females are generally too heavy to fly, particularly when carrying eggs, a contrast to the smaller males, who retain flight capability.

The second newly identified species, Anchiale magliensis, inhabits the critically endangered Mabi rainforest on Queensland’s Atherton Tablelands. Females of this species measure approximately 11 to 12 centimeters and produce eggs featuring an unusual detachable "lid" that comes off upon hatching, according to Dr. Jones.

In total, the study revealed that what had previously been classified as two stick insect species are actually five distinct species distributed from northern New South Wales to tropical north Queensland. This refined classification highlights narrower habitat ranges for these insects than previously appreciated, which carries significant implications for their conservation.

Dr. Jones emphasized that despite Anchiale stick insects being among the most frequently recorded species on citizen science platforms—due in part to their ability to hatch in large numbers—much about their biology and diversity remains unknown. The researchers also noted the potential discovery of an additional new species in Cape York, although further specimens are required to confirm this.

This latest discovery adds to recent findings in the area, including the identification last year of Acrophylla anta, a species from the Atherton Tablelands measuring 40 centimeters in length and weighing slightly less than a golf ball. The region is also home to Australia’s longest stick insect species, the gargantuan stick insect, whose females can exceed half a meter in length.

Together, these studies underline the rich, yet incompletely documented, stick insect diversity in northeastern Australia and underscore the importance of continued research and conservation efforts.