Madagascar
Fine-art photographic collection
Holonychus saxosus
A Madagascan weevil wearing a removable coat of blue scales over black armour.
About this species
Holonychus saxosus(Coquerel, 1859)
Information reviewed15 July 2026
Holonychus saxosus is a large broad-nosed Madagascan weevil whose mineral-blue appearance comes from dense microscopic scales. The underlying exoskeleton is dark, so age and abrasion can visibly change the beetle's colour.
Taxonomy
Animalia · Arthropoda · Insecta · Coleoptera · Curculionidae · Holonychus
Accepted taxon. · checked 2026-07-15
MadagascarBroad range and selected reference localities — not a complete occurrence map.
Humid Malagasy forest, including the Andasibe region.
Adults climb vegetation and may be encountered on foliage or trunks.
Plant-feeding adult weevil; precise host plants are not well established.
Solitary.
What makes this species remarkable?
The blue surface is a layer of separate scales rather than blue shell; worn areas expose the black cuticle and reveal how the colour is constructed.
The heavy fused-looking elytra form a rock-like armoured dome, while the short broad snout places chewing mouthparts directly beneath the head.
Its exceptionally robust exoskeleton has been sampled in comparative research on beetle chitin, turning the protective shell itself into scientific material.