Hemiscolopendra marginata

Hemiscolopendra marginata, the eastern bark centipede, is a common species of centipede found in the Eastern United States and parts of Mexico.^[2][3][4] The species commonly shelters beneath loose bark on dead or fallen trees. H. marginata is the first centipede species shown to exhibit sexual dimorphism in venom composition.^[5]

Hemiscolopendra marginata is a moderate-sized scolopendrid centipede. Examined specimens have ranged from 27.8 to 54.8 mm in length and 2.7 to 7.8 mm in width.^[4] The species lacks the distoventral spur on the first tarsi of the ambulatory legs, a feature that distinguishes it from species of Scolopendra.^[4]

Hemiscolopendra marginata is a predatory species that primarily feeds on invertebrates, typically found beneath loose bark or within decaying wood. Like several other centipede species, females exhibit maternal care, guarding eggs and early juveniles.^[5]

Research has demonstrated that Hemiscolopendra marginata exhibits sex-based differences in venom composition. A 2019 study using chromatographic, transcriptomic, and proteomic analyses found that male and female individuals produce venoms with substantially different toxin profiles. Male venom was dominated by ion-channel–modulating toxins and several previously undescribed toxin types, whereas female venom contained higher concentrations of γ-glutamyl transferases and CAP proteins (cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 proteins). This study represents the first documented example of sexual variation in venom composition in a centipede.^[5]