Armoured Amazon female† moths: urticating setae in Notodontidae (Lepidoptera)

Urticating setae in the corethrogyne of female moths of Notodontidae (Anaphinae and Thaumetopoeinae) from Africa, Asia, and Australia were compared using light and scanning electron microscopy. In all 14 species examined, the proximal tip of the setae was spear-shaped with a lateral opening and had lobed or serrated barbs. Notable variation among genera was observed at the distal end of the seta, characterized by 5 non-exclusive forms: tapered (genera Adrallia Walker, Anaphe Walker, Hypsoides Butler, Paradrallia Bethune-Baker, and Tanystola Turner), spatulate (genera Adrallia, Epanaphe Aurivillius, Epicoma Hübner, Hypsoides, and Trichiocercus Stephens), blunt (genus Paradrallia), cup-shaped (genus Ochrogaster Herrich-Schäffer), or hook-shaped (genus Gazalina Walker). Verrucose projections on the distal end of the seta were present in 4 genera of Anaphinae (Adrallia, Anaphe, Epanaphe, and Hypsoides) and in 1 genus of Thaumetopoeinae (Epicoma), and their functional significance is discussed. Phylogenetic analyses of the cytochrome c oxidase subunit I gene region provided a framework for comparing setal morphology and geographic distribution among genera. This study is the first to compare and describe the morphology of urticating setae across females of multiple notodontid species. The shared setal morphologies, which appear to enhance aerodynamics and facilitate toxin dispersal, indicate that notodontid moths have evolved highly effective defense strategies and protection of their egg mass.