biostudies-literatureDjeghdi KAdolphe Merkle FoundationSwiss National Science FoundationEuropean Research Council2509-2517https://www.ebi.ac.uk/biostudies/studies/S-EPMC10933740biostudies-literatureUnknown20(11)While artificial photonic materials are typically highly ordered, photonic structures in many species of birds and insects do not possess a long-range order. Studying their order-disorder interplay sheds light on the origin of the photonic band gap. Here, we investigated the scale morphology of the <i>Anoplophora graafi</i> longhorn beetle. Combining small-angle X-ray scattering and slice-and-view FIB-SEM tomography with molecular dynamics and optical simulations, we characterised the chitin sphere assemblies within blue and green <i>A. graafi</i> scales. The low volume fraction of spheres and the number of their nearest neighbours are incompatible with any known close-packed sphere morphology. A short-range diamond lattice with long-range disorder best describes the sphere assembly, which will inspire the development of new colloid-based photonic materials.Soft matter<i>Anoplophora graafi</i> longhorn beetle coloration is due to disordered diamond-like packed spheres.PMC10933740PrISMoIDNCCR Bio-inspired Materials833895Steiner UBauernfeind VDjeghdi KSchumacher CWilts BDGunkel Ifalse<i>Anoplophora graafi</i> longhorn beetle coloration is due to disordered diamond-like packed spheres.While artificial photonic materials are typically highly ordered, photonic structures in many species of birds and insects do not possess a long-range order. Studying their order-disorder interplay sheds light on the origin of the photonic band gap. Here, we investigated the scale morphology of the <i>Anoplophora graafi</i> longhorn beetle. Combining small-angle X-ray scattering and slice-and-view FIB-SEM tomography with molecular dynamics and optical simulations, we characterised the chitin sphere assemblies within blue and green <i>A. graafi</i> scales. The low volume fraction of spheres and the number of their nearest neighbours are incompatible with any known close-packed sphere morphology. A short-range diamond lattice with long-range disorder best describes the sphere assembly, which will inspire the development of new colloid-based photonic materials.2024-01-01T00:00:00Z2024 Mar2026-04-12T15:29:58.499Z2025-04-04T12:59:14.373ZS-EPMC109337403838943710.1039/d4sm00068d