Tricolour Millipede (Pelmatojulus tectus)

In 1897 the American naturalist O. F. Cook named a big millipede from a single broken male in the Hamburg museum, labelled as coming from Zanzibar. Nobody collected another for 120 years. When the species turned up again, in 2017, it was on the other side of Africa, in the coastal forests of Cameroon, and it was a striking animal: every ring of its body banded bright yellow, orange-red and deep black. This is that millipede, Pelmatojulus tectus, which I sell as the Tricolour Millipede.

Lost, found and reclassified

Cook called it Pachybolus tectus, and for more than a century the name rested on that one specimen, which has since been lost. In 2017 three animals were collected in the Littoral Region of Cameroon, near Yabassi, Djawara and Yansoki, two of them in secondary forest and one of those under dead leaves. A 2018 paper in the journal Zootaxa re-described the species from them, moved it into the genus Pelmatojulus and concluded that the Zanzibar label was probably a mistake. Then, through 2020, a year-long survey of Douala-Edéa National Park on the Cameroon coast found 45 of them, in primary forest, mangrove and open meadow.

Names, and the Amber Millipede question

Conservation work in Cameroon calls it the giant tri-coloured African millipede, and I have shortened that to Tricolour Millipede. It is seldom offered in the UK, where it has also been sold as the Yellow Banded Millipede, a name more often given to the much smaller Caribbean bumblebee millipede, Anadenobolus monilicornis. Cameroonian animals have been sold as Pelmatojulus ligulatus as well, but that species was described from Lagos, its records come from Benin, Nigeria and Ghana, and it is missing from the 2023 checklist of Cameroon's millipedes. Cameroon does have two other Pelmatojulus, P. excisus and P. brachysternus, and the species are told apart by the shape of a male's gonopods, the modified legs used in mating. Trade animals are usually named from their colour and where they are said to come from, not from an examination of the males, so treat the name on stock like mine as the trade's rather than a checked identification. I list mine as P. tectus, the name this stock is sold under, as animals said to come from Cameroon, the origin in my care panel. They are not the animal I sell as the Amber Millipede.

Appearance and size

In the 2018 paper's description from life, each body ring has a bright yellow front band, an orange-red middle and a sharply contrasting black rear, so the body reads as hoops of yellow, orange and black. The head, the first ring behind it and the tail end are brown, and the antennae, legs and underside are yellow-brown.

The 150mm in my care panel is the body length that paper gives for the male and the female it describes, each about 1.5cm thick; the male has 53 leg-bearing rings and the female 54.

Care and set-up

The coastal park where the 2020 survey found them averages 24 to 29°C month by month, with rain for about nine months of the year. The 24 to 28°C in my care panel is my own figure, the band I use for the Amber Millipede, the other Pelmatojulus on my list; I can find no published figure for this species, but that band sits inside the park's averages. A 24°C floor is above anything an average English home reaches in any month: the average is 19°C from October to April and 21.5°C in July and August. So the tub needs a heat mat or heat cable on a thermostat, set against a side wall, never underneath, because a millipede escapes heat by digging down, and a mat beneath leaves it nowhere to go.

Give it at least 15cm of substrate, the length of the adults measured in 2018, because millipedes moult buried in the bed and a layer that is too shallow can end in a failed moult. Make the base from organic topsoil and flake soil, generously mixed with white-rotted hardwood such as my shredded rotten wood, then cover it thickly with leaf litter, where tough magnolia leaves last longer than softer kinds. A piece of cork bark gives it a dark place to hide. Keep the bed damp from top to bottom without letting it turn waterlogged, with enough ventilation that the tub never smells stale. The humidity in my care panel, 80 to 90 per cent, is my own figure too, the range I use for the Amber Millipede; I can find no published figure for this species.

When you handle one, keep it low over the tub and let it walk from hand to hand rather than gripping it. I can find no analysis of its own secretion, but millipedes of its order, the Spirobolida, defend themselves with benzoquinones. These can stain skin brown for days to weeks, and in an eye they can cause a chemical burn that needs treating promptly. Afterwards, use soap and water on your hands before they go anywhere near your face, make sure children do too, and if any gets in an eye, rinse it out and have it looked at straight away. My article on whether millipedes are dangerous goes through the risks in full.

Diet

Decaying leaves and white-rotted wood are the staple, and keepers of its relatives report that they take little else, so keep both well stocked and treat anything more as an extra. A piece of soft fruit or some vegetable now and then, and a little fish flake once in a while, are worth offering; remove leftovers within a day. Calcium should never run out; Malawi light limestone is an easy way to supply it. After a moult, leave the old skin where it lies, since most millipedes eat theirs.

Breeding

I can find no published account of how P. tectus breeds. In Epibolus pulchripes, an East African millipede of the same family, the female seals each egg into a capsule of soil, laying 10 to 15 at a time, and spirobolid young have only three pairs of legs when they emerge, then add rings and legs at each moult. One keeper on a hobby forum reported egg capsules within a week of their Cameroonian animals arriving, and young a few months later, from stock they identified as P. tectus. Those capsules sit hidden in the bed, so once the tub is running, leave the substrate undisturbed and keep the wood coming. Spirobolids generally live for several years, though I can find no lifespan recorded for this one, and a wild-caught adult arrives at an age no one can know; my article on how long millipedes live has the wider picture.

Who the Tricolour suits

It is best for someone who has kept a large species before and already runs a heated tub. Mine are wild-caught. Animals taken from the wild are often slower to settle than captive-bred ones, so have the tub set up and up to temperature before they arrive, then leave them in peace for the first few weeks. In return you get a species that went unrecorded for 120 years.

Each order of Tricolours goes out in a ventilated tub on a bed of damp moss, boxed in double-walled cardboard, and on cold days a heat pack travels with it. Parcels leave Monday to Thursday, and my live arrival guarantee takes in every livestock order, Tracked 24 or Next Day alike.