Unknown biodiversity hiding in plain sight: unravelling the origins, diversity and evolution of Horned Bugs on thorny plants.

By 11/23/2021Current Projects
HSF 21127 | Amount: $84,000 | Project Leader: G Cassis | Project Period:

A project undertaken at the University of New South Wales, and supervised by Prof Gerry Cassis.

The insect biota of Australia remains largely undescribed, with ~30% of species estimated to be described. This biodiversity impediment is greatest in arid and semiarid Australia where there has been a profusion of new work on insect clades, which have been the least explored regions relative to mesic and tropical regions of the continent. This project tackles one such clade – the Horned Bugs – a tribe of stink bugs called the Deroploini (family Pentatomidae).

These insects have remarkable body ornamentation that appear to mimic the thorns of their perennial host plants. Their unique phenotype may be an outcome of their xeric lifestyle and adaptation to the anti-herbivory traits of their hosts, particularly their large thorns, enabling these bugs to ‘hide in plain sight’. These bugs have not been studied for almost a century and yet a large number of undescribed species are held in museum collections that await rediscovery and modern analysis.

The main objectives of this project are to determine the origins and diversification of Horned Bugs, focusing on the evolution of the aforementioned ornamental traits. In the process we will assess the timing of the speciation of the Horned Bugs, and assess if this is an ancient clade or a more modern radiation associated with the Cenozoic aridification of the continent.

These objectives will be addressed through a combination of modern species surveys, molecular phylogenetics, trait evolution analysis, and divergence dating. This will also result new species, an activity long recognised as essential to managing Australia’s environments.