The spirobolidan millipede Acladocrieus setigerus (Silvestri, 1897)
grows to at least 155 mm long and is so far known only from Chuuk Islands,
Micronesia. It occurs mainly in well-shaded habitats, usually on the forest floor
and on tree trunks. It sprays defensive secretions from paired, lateral ozopores
on trunk segments; the major compounds, identified here for the first time, are
benzoquinones. The secretion stains human skin a reddish brown and causes a
slight burning sensation, occasionally followed by slight blistering and exfoliation.