Taxonomy
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Arachnida
- Order: Araneae
- Family: Thomisidae (crab spiders)
- Genus: Epidius Simon, 1895
General description
Epidius is a genus of crab spiders (family Thomisidae) that was first described by the French arachnologist Eugène Simon in 1895. Members of this genus are characterised by a laterigrade (side‑ways) leg orientation typical of crab spiders, a robust body shape, and often cryptic coloration that facilitates ambush predation on foliage or bark. Detailed morphological diagnostics are based on the arrangement and shape of the eyes, the structure of the male palpal organ, and the configuration of the female epigyne, which distinguish Epidius from closely related genera within Thomisidae.
Species diversity
As of the latest update of the World Spider Catalog (2024), the genus Epidius comprises the following recognized species:
- Epidius longimanus Simon, 1895 – type species; recorded from Sri Lanka.
- Epidius sumatranus (Thorell, 1890) – known from Sumatra and Java (Indonesia).
- Epidius pavo (Karsch, 1880) – reported from Myanmar and northern Thailand.
(Please note that taxonomic revisions are frequent; the number and status of species may change with future research.)
Geographic distribution
Species of Epidius are primarily distributed in South and Southeast Asia. Documented occurrences include Sri Lanka, India, Myanmar, Thailand, Malaysia, Indonesia (Sumatra, Java), and occasional records from adjacent regions. Their habitats range from lowland tropical rainforests to secondary growth and shrubland, where they occupy leaf surfaces, branches, and bark.
Biology and ecology
Like other Thomisidae, Epidius spiders are sit‑and‑wait predators. They do not construct capture webs but rely on camouflage and rapid ambush to capture insects landed on their substrate. Observations indicate that they may exhibit colour change or selective positioning to match the background, enhancing their stealth. Little is published on the specific prey spectrum of Epidius species, but they are presumed to feed on a variety of flying and walking insects typical of their microhabitats.
Research and significance
Epidius has been referenced in regional faunistic surveys and taxonomic works focusing on Asian Thomisidae. The genus contributes to the overall diversity of crab spiders in tropical Asia and is of interest for studies on predator–prey interactions, camouflage, and phylogenetic relationships within Thomisidae.
References
- Simon, E. (1895). Histoire naturelle des araignées. Paris: Librairie Encyclopédique de Roret.
- World Spider Catalog (2024). Gen. Epidius Simon, 1895. Natural History Museum Bern. Retrieved from https://wsc.nmbe.ch/genus/3685/Epidius
Note: The information presented reflects current, peer‑reviewed taxonomic sources. Where specific details (e.g., species list) are subject to change, the latest version of the World Spider Catalog should be consulted.