About Arima marginata (Fabricius, 1781)
Arima marginata exhibits clear sexual dimorphism in body size: females reach a body length of approximately 12–20 mm (0.47–0.79 in), while males only reach about 6–12 mm (0.24–0.47 in), meaning females are generally much larger than males. Females also outnumber males in this species. These beetles have a shiny black body with orange marginal bands along the edges of the pronotum and elytra. Their elytra only cover two abdominal segments. Their antennae are filiform, and their abdomen is voluminous. The last sternite is a single, ginkgo leaf-shaped structure, while the genital plate is formed from two parts. These beetles cannot fly, but they are very active. This species is found only in southeastern France and northwestern Italy.
