Isopods in Planted Vivariums
Isopods also have a place in planted vivariums without large animals to keep them in check. Isopods are beneficial to plants for a few reasons; they burrow and aerate the soil, they break down dead plants and other organic matter, and the waste from isopods (called “frass”) fertilizes the plants. Some people keep isopods in vivariums as display animals! They are a great low maintenance animal that occupies little space.
Armadillidium nasatum swarming a fresh potato shoot.
Armadillidium maculatum swarming moss. It will typically be eaten within a few days, as they prefer it to their staple of dried leaves. Photo credit: Peihan Orestes
Some care must be taken when selecting a species to house with plants or, which plants to house with the isopods. Members of the Armadillidium genus are a poor choice for nearly all plants due to how voracious they are for living plant matter. Armadillidium, when offered moss, soft bodied plants (such as baby’s tears), or even fresh plant shoots will decimate the flora within days. Armadillidium nasatum has gained a reputation as a pest in greenhouses because captive populations will eat baby plant shoots before they can grow out of the vulnerable stage.
Trichorhina tomentosa on a stripped leaf. These isopods are a docile, safe option for nearly any terrarium.
Dwarf purple isopods reach a maximum size of 3mm.
When considering isopods for delicate plants, it is best to err on the side of caution and choose one of the many dwarves available. Trichorhina tomentosa, commonly known as the “dwarf white isopod”, is the most widely available and well-known dwarf. Even while reaching swarm conditions, dwarf whites are a harmless roommate to the most sensitive plants. They are rarely seen, spending most time submerged below the surface and thrive in very humid conditions, making them ideal for most plant setups. “Dwarf purple isopods” is another popular option, although these have only scientifically been identified as the Family level with the classification system and are designated as Trichoniscus sp. The dwarf purples currently being traded are believed to be at least 3 different species.
Agabiformius lentus is a more robust dwarf with a slightly larger size of 5mm.
Nagurus cristatus are very similar to A. lentus
There are additional, slightly larger but slower to reproduce dwarf species that may be used with plants. Agabiformius lentus is a charismatic little isopod that is quite underrated. They have a rather robust body offering a chubby visual and are one of many species that “play dead” once discovered. The first time this occurs, it can be alarming, because they are perfectly motionless and belly up, but if left alone they will correct themselves and scoot away. This playing dead behavior is also an excellent opportunity to observe which isopods are gravid, as the underside is completely unguarded, and the marsupium exposed. Nagurus cristatus, or "dwarf grey" is similar in appearance to A. lentus and behavior. Niambia capensis is a species similar in size to A. lentus but a thinner body and does not play dead. We don’t really have fun facts about N. capensis, but they do naturally present in a variety of colors.
Atlantoscia floridana are kinda creepy in behavior but perfectly harmless.
Rhyscotus texensis are what A. floridana would look like if the floridana allowed themselves to get fat.
If observing isopods isn’t a great concern, there are small, fast moving dwarves that are an option. At first, keeping them can be unsettling because their body appearance and movements are similar to that of many past species like lice, but they are perfectly harmless and still beneficial. Atlantoscia floridana and Rhyscotus texensis are two such examples of these species. An added tidbit is that these are also two species that are native to North America!
Venezillo parvus are adorable and not to be trusted with plants.
One dwarf species that should be avoided is Venezillo parvus. Like the Armadillidium genus, V. parvus has an appetite for plant matter. They are a small species that rolls tightly into a ball, earning them the nickname “dwarf roly-poly”. This species is also native to North America.
P. pruinosus is available in 4 colors: classic blue, orange, white, and piebald!
Porcellionides pruinosus is a larger species still that is docile and known for their compatibility with sensitive reptiles; similarly, it can be housed with sensitive plants. This fearless species can frequently be observed out and exploring their environment among debris and plants.
For keepers that do intend to keep the notorious plant destroyers, there are still options. Hardier, less tasty plants must just be selected to grow with the isopod cultures. Pothos is a very popular plant due to its quick growth rate and near-indestructibility. Hoyas and other rubber plants are left untouched by most isopod species. Thick structured plants such as bromeliads, orchids, and Tillandsia are safe from the mouth parts of tiny land crustaceans. The vining plant English ivy is also another option that can be grown with isopods.
Porcellio expansus is an impressively large isopod.
Another popular inquiry is what isopods can be housed in arid environments. While isopods cannot be housed in exclusively arid environments, semi-arid is an option. Isopods that are resistant to drying out, or desiccation, include those of the Porcellio genus, in particular many people enjoy keeping the large Spanish species available on the market in display vivariums. Species such as P. expansus, P. magnificus, and P. spatulatus are exceedingly popular. The species P. scaber is a much cheaper option that is available in a variety of colors and patterns. These isopods can be housed with plants that require a drier environment, but it is prudent to have a smaller moist area under a slab of bark or stone for the isopods to retreat to and wet their gills. Without some constant source of moisture, even a small amount, the isopods will not survive.