[5] In 1928 George Hudson placed this species within the Oeceticus genus and amended its epithet to omnivorous.

[2] The male is a hairy, black moth with translucent wings and a tapered abdomen[2] and a 28–38 mm wingspan.

[3][8] When ready to emerge, the male pupa forces its way to the narrow exit of the bag and extends the front part of the body through the hole.

The caterpillars emerge through the narrow end of the female's bag and disperse via crawling, lowering themselves on silk threads or by wind.

Tachinids, primarily Pales feredayi and P. marginata, lay their eggs on foliage which are then ingested by the bagworm caterpillar.

[7] The maggots then eat through the gut wall and feed on the caterpillar, leaving the host's body when it dies and pupating within the bag.

[2] The tachinid larvae are in turn eaten by another parasitoid wasp, which bites small, round emergence holes in the side of the bag.

[3] X. rhopaloceros was released in New Zealand in the 1960s as a biocontrol agent against the light brown apple moth but was not sufficiently host-specific to have much impact.