Probably one of the largest terrestrial isopods by its sheer bulk. Helleria brevicornis is a burrowing species, living most of its life buried in the soil.
While it is widely documented that this species only breeds once in its lifetime, some breeders have reported multiple successful breeding attempts (once a year) by individual females. It was later deduced by invertebratedude that this was only made possible with the simulation of an annual winter diapause. Invertebrates that truly breed only once in their lifetime typically die soon afterwards. For Helleria brevicornis, the females live on for quite some time after breeding so this theory makes a lot of sense.
