Ethmostigmus

The animals we now call Ethmostigmus were originally described in the 1800s under Scolopendra – for example, the current type species Ethmostigmus trigonopodus started life as Scolopendra trigonopoda Leach, 1817. The genus Ethmostigmus was erected by R. I. Pocock in 1898, to hold a distinctive group of scolopendrids with large rounded spiracles and certain head/forcipule characters. Attems (1930) later fixed Scolopendra trigonopoda Leach, 1817 as the type species of Ethmostigmus by subsequent designation, which is still the standard today.

By the mid–late 1900s, Ethmostigmus was recognised as a widespread Old-World tropical genus from Africa through Asia to Australia and the SW Pacific. The first major modern revision was Koch (1983), who did a full taxonomic study of Australian Ethmostigmus (including E. rubripes and several regional forms), clarifying morphology and distributions there.

Parallel work and catalogue efforts in Africa and SE Asia refined species lists and synonymies but left many “colour forms” and local variants unresolved, which is why the hobby ended up with a lot of loosely labelled “giant centipede” morphs. NCBI / catalog resources consolidated Ethmostigmus as a single genus in Scolopendridae, subfamily Otostigminae, but didn’t resolve species limits.

Starting around the 2010s, integrative taxonomy (DNA + morphology + geography) really reshaped the genus:

• Joshi & Edgecombe (2018, 2019) used molecular phylogenetics to confirm Ethmostigmus as monophyletic and uncovered multiple, often micro-endemic lineages in peninsular India, describing new species such as E. agasthyamalaiensis and E. sahyadrensis.

• Their evolutionary biogeography work showed that the group’s deep history tracks Gondwanan breakup, with later dispersal events across Africa–India–Australia shaping modern diversity.

Recent Chinese work has added four new species and one status change based on combined morphology and multi-gene datasets, highlighting that East and SE Asian diversity was also underestimated. Modern catalogues and checklists now recognise dozens of valid Ethmostigmus species and subspecies (counts differ by source as new descriptions appear). Classic “hobby staples” like E. trigonopodus (African giants) and E. rubripes (Australian/Island giants) are just two branches of a much richer radiation, with many regionally restricted, look-alike species that can only be separated reliably with close morphology and/or genetics.

Ethmostigmus sp. "Thailand" (rubripes complex)

Common Name: Giant Asian Centipede

Origin: Thailand

Lifestyle: Terrestrial and burrowing like most giant centipedes.

Adult Size: Likely around 8-10", heavier bodied than Scolopendra.

Growth Rate: Other Ethmostigmus are moderate-to-fast growers and relatively long-lived. It is very likely that Thai Ethmostigmus are similar in this regard.

Temperament: Nervous and defensive, not afraid to bite if handled. Bite reports from other Ethmostigmus species range from "like a bad wasp sting" to "extreme pain for days."

Color & Appearance: Collected specimens display reddish-brown or orange tergites with pale-orange legs and bright red terminal legs. This is not typical of the usually yellow-legged E. rubripes found in Asia and Oceania, indicating that it may be a subspecies or local color form.

Species History

This is an undescribed species that is treated as a hobby-placeholder for Ethmostigmus species collected in Thailand, almost certainly part of the E. rubripes species complex.

Ethmostigmus rubripes was described in 1840 from Java and later shown to be widespread across Asia and Oceania, with subspecies that bleed into mainland SE Asia. For a long time, most large yellow-legged Ethmostigmus from Asia were lumped under E. rubripes, regardless of fine-scale geography. Koch’s revision of Ethmostigmus in Australia and later work in India showed lots of regional differentiation inside what used to be treated as single “wide” species. Joshi & Edgecombe (2018/2019) used DNA + morphology and found multiple, often micro-endemic Ethmostigmus species in India, demonstrating that “one giant species over half a continent” is usually an oversimplification.

Siriwut’s 2015 PhD on Thai scolopendromorphs lists Ethmostigmus as one of nine scolopendrid genera in the country, but the abstract makes it clear the detailed taxonomic work was concentrated on Scolopendra and a few other genera, not Ethmostigmus yet. No later open-access paper has come out saying “here is the Thai Ethmostigmus revision” or naming a Thai-endemic Ethmostigmus species. Meanwhile, general-audience pieces about dangerous wildlife in Thailand treat the local giant yellow-leg as E. rubripes. Right now, Thai Ethmostigmus are in taxonomic limbo – probably part of the broader E. rubripes complex, but awaiting the same kind of DNA-backed revision India and Australia have had.

The specific name “Ethmostigmus sp. Thailand” is in use at least by 2019 in Arachnoboards’ media gallery, attached to a WC animal originally gifted as “dehaani” and later re-identified as Ethmostigmus. By mid-2020s, US/online dealers list “Ethmostigmus sp. Thailand – Giant Asian Centipede” as a regular stock item, always marked WC and with no species-level ID beyond “sp.”

Natural Habitat

In the wild, Thai Ethmostigmus live on the shadowed floor of tropical forests, where the air stays warm and humid year-round. Thailand’s lowland and hill forests build a deep layer of leaf litter, fallen logs, and loose bark, and our centipedes spend their days tucked away in these sheltered pockets or under rocks and buried wood.

They emerge after dark to hunt through the moist soil and decomposing leaves, sharing the forest floor with termites, roaches, snails, and other invertebrates that thrive in the same microhabitats. Like other giant Ethmostigmus, they’re found in both evergreen rainforest and seasonal forest so long as they have consistent ground moisture and deep cover to prevent them from drying out.

This “hidden under the log” lifestyle is what we aim to recreate in captivity: a deep, slightly compactable substrate, generous leaf litter, and plenty of tight hides, kept warm and never allowed to fully dry, while staying mindful of mycosis.