invert
Isopod Colony (Dwarf White)
Trichorhina tomentosa
Dwarf white isopods aren't kept as display animals in the way a tarantula or gecko is — they're kept as a working colony, the cleanup crew that quietly processes waste, mold, and leftover feeder-insect remains inside a bioactive terrarium so the keeper doesn't have to spot-clean as often. What makes this species particularly suited to that job, beyond its small size letting it work into tight substrate spaces other isopods can't reach, is that Trichorhina tomentosa reproduces parthenogenetically — the colony is effectively all female, and individuals produce viable offspring without needing to mate, which is why a small starter culture can build into a self-sustaining population relatively quickly under the right conditions without the pairing logistics other isopod species require. They're burrowing detritivores rather than surface foragers, spending most of their time under leaf litter, bark, or the top layer of substrate rather than out in the open. Because of their small size and shy, subsurface habits, dwarf whites are also a favored feeder-insect option for very small dart frogs and other tiny insectivores that can't manage larger prey, giving the colony a dual role as both a cleanup crew and a renewable food source in a mixed collection.
1-2 years per individual, but a healthy colony is effectively self-sustaining indefinitely
Roughly 1/8 inch (3mm) as adults — among the smallest isopod species commonly kept
Believed native to South America; now cosmopolitan and widely cultured in the terrarium hobby worldwide
Husbandry
- A dedicated starter culture bin (roughly a 6-quart / 6L container) or directly seeded into a host bioactive terrarium of any size with enough leaf litter and hides to establish
- Source: British Tarantula Society invertebrate husbandry guidance (checked 2026-06-01)
- 72-78°F (22-26°C) is the reliable reproduction range; the colony tolerates a wider range but breeds and grows more slowly outside it
- Source: British Tarantula Society invertebrate husbandry guidance (checked 2026-06-01)
- High and consistent — substrate should stay damp (not waterlogged) throughout, with one drier corner if the enclosure is large enough to support a gradient
- Source: British Tarantula Society invertebrate husbandry guidance (checked 2026-06-01)
- Decaying leaf litter and wood as a staple, supplemented with occasional fish flakes, powdered spirulina, or fruit/vegetable scraps to boost breeding rate
- Source: British Tarantula Society invertebrate husbandry guidance (checked 2026-06-01)
- A calcium source (cuttlebone, crushed eggshell, or a dedicated calcium supplement) placed in the substrate supports shell hardening after molts and is especially useful when the colony is being bred up for feeder production
- Source: British Tarantula Society invertebrate husbandry guidance (checked 2026-06-01)
- Colonial by design — dwarf whites thrive in dense groups and should never be kept as isolated individuals, which stalls reproduction and offers no benefit over colony housing
- Source: British Tarantula Society invertebrate husbandry guidance (checked 2026-06-01)
- A deep (2-4in+) bioactive mix of coco fiber, leaf litter, and decaying wood over a drainage layer, replenished with fresh leaf litter regularly as the colony consumes it
- Source: British Tarantula Society invertebrate husbandry guidance (checked 2026-06-01)
Honest disagreement among sources
Current best practice: Build a dedicated culture bin up to a healthy, visibly reproducing population before splitting any off into a display bioactive terrarium, since a very small starter group seeded directly can struggle to establish under normal terrarium conditions
Noted disagreement: Some keepers seed a display terrarium directly with a modest starter culture and accept a slower establishment period, preferring not to maintain a separate culture bin long-term once the terrarium's ecosystem is mature enough to sustain the colony on its own
Handling
This is not a species anyone handles individually in any meaningful sense — dwarf whites are managed as a colony, not as pets to pick up. The closest thing to 'handling' is transferring leaf litter or a scoop of substrate (and the isopods riding along in it) when seeding a new enclosure or splitting a culture to start a second colony. Because the whole point of keeping them is passive, low-maintenance waste processing, day-to-day interaction is really just observation: checking that individuals are visible near the surface after misting (a sign the colony is active and the substrate moisture is acceptable) and confirming population density looks stable or growing over time. A well-established colony is largely self-regulating — it does not need daily attention the way an individual pet does, and the main ongoing task is simply replenishing leaf litter and other food sources before the existing supply is fully broken down.
Signs of good health
- Individuals visible foraging near the surface shortly after misting or lights-out
- A visibly growing or stable population size over successive weeks, including small juveniles alongside adults
- Normal pale-white to cream coloration without unusual discoloration or a die-off smell from the substrate
- Active burrowing and leaf-litter consumption evident in the substrate
- No mass surface die-offs, which usually signal substrate that's gone too wet, too dry, or contaminated
- Visible females carrying a marsupium (brood pouch) of developing young, a normal and encouraging sign of active reproduction
- Steady consumption of added leaf litter and food scraps rather than untouched, moldering material building up
Common problems
12 common invert problems are tracked for this species; 0 have full guides published so far.
Recommended gear for Isopod Colony (Dwarf White)
Equipment categories that are genuinely correct for this species' welfare needs — see the full Gear Guide for the complete list.
Digital infrared temperature gun
Measures actual basking SURFACE temperature, not just ambient air — a stick-on dial thermometer reads air temp, which is a poor proxy for the surface temp that drives digestion and thermoregulation.
Simple, easy-to-sanitize quarantine enclosure
A separate, minimal, easy-to-bleach-and-rinse enclosure (as opposed to the animal's permanent bioactive setup) makes a genuine multi-week quarantine period realistic — see the Quarantine Timeline Planner tool for recommended duration.
Digital gram scale
Regular weigh-ins are one of the earliest, most objective ways to catch a developing health problem (weight loss often precedes visible lethargy) — a cheap kitchen-grade gram scale is accurate enough for routine tracking.
Some links below are Amazon Associates / Chewy affiliate links — Keepers Guide may earn a small commission on qualifying purchases, at no extra cost to you. We only recommend equipment categories that are genuinely correct for the species' welfare needs; we never recommend a product because of the commission.
This is general educational care information, not veterinary diagnosis. For a sick or injured animal, see a qualified exotic-animal vet promptly — especially for anything acute (not eating combined with lethargy, breathing changes, bleeding, or any sudden behavior change). Nothing on this page substitutes for an in-person exam.