BlattodeaAmitermes meridionalis Anamesia sp Balta bicolor Bush Cockroach Ellipsidion Ellipsidion australe Ellipsidion humarale Nasutitermes triodiae Termite — Alate

This photo of a beautiful native cockroach was taken in Randwick (located in Sydney), New South Wales.

Our best educated guess is that this is the species Balta bicolor, although there are many similarities with species Elipsidion humarale.

Sometimes mistaken for an Ellipsidion species such as Elipsidion humarale, which are a robust looking cockroach and convex with fully opaque pronotum (the pronotum covers the head) and have similar colouration. The pronotum of the following native cockroach is transparent.

Native Cockroach (Balta bicolor), Randwick NSW © Jennifer Mather
Native Cockroach (Balta bicolor), Randwick NSW © Jennifer Mather

The genus Balta are small, slender and flattened, with transparent pronotal margins. Whilst most Balta are nocturnal, the species Balta bicolor is diurnal (active in the daytime), like the Ellipsidion species that are also diurnal, adds to the confusion with identification.

Native Cockroach (Balta bicolor), Randwick NSW © Jennifer Mather
Native Cockroach (Balta bicolor), Randwick NSW © Jennifer Mather

We certainly welcome feedback on the ID of this species. You can either email us or comment on our Facebook page: www.facebook.com/ausemade


  • Scientific classification
  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Subphylum: Hexapoda
  • Class: Insecta
  • Informal: Pterygotes
  • Order: Blattodea
  • Superfamily: Blaberoidea
  • Family: Ectobiidae
  • Subfamily: Pseudophyllodromiinae
  • Genus: Balta
  • Species: Balta bicolor

Footnote & References

  1. Photos © Jennifer Mather
  2. Balta bicolor, Project Noah, https://www.projectnoah.org/spottings/8533400
  3. Balta bicolor, iNaturalistAU, https://inaturalist.ala.org.au/taxa/415893-Balta-bicolor
  4. Balta bicolor Hebard, 1943, Atlas of Living Australia, https://bie.ala.org.au/species/Balta bicolor
  5. Balta bicolor, A Guide to the Cockroaches of Australia, by David Rentz, p260, https://www.publish.csiro.au/book/6710/

BlattodeaAmitermes meridionalis Anamesia sp Balta bicolor Bush Cockroach Ellipsidion Ellipsidion australe Ellipsidion humarale Nasutitermes triodiae Termite — Alate