Diploptera punctata, the Pacific beetle cockroach, is a compact, beetle‑like blaberid best known for its extraordinary reproductive biology. Unlike most insects, this species is truly viviparous: females gestate their young internally and nourish them with a crystalline, protein‑rich “milk” produced in a specialised brood sac. This unusual strategy has made the species a cornerstone of endocrine and developmental research, particularly around juvenile hormone regulation.
 
In appearance, adults are small—usually under 2 cm—and have hardened, beetle‑mimicking forewings that give them a distinctive, glossy silhouette. They inhabit forested and coastal environments across Southeast Asia and the Pacific, where they shelter in leaf litter and rotting wood. When threatened, they can deploy a potent quinone spray from tracheal glands, a defence that deters many predators.
 
Their life cycle is simple: four nymphal instars followed by a winged adult stage. Nymphs develop more rapidly when kept in groups, a behavioural trait often noted in captive colonies. Because of their manageable size, gentle nature, and scientific importance, D. punctata is widely maintained in research facilities and occasionally by specialist hobbyists.