The Water Scorpion (Laccotrephes tristis) is found throughout Australia. They are carnivorous insects that hunt near the water surface. Usually found in shallow stagnant and slow-moving water. They can be found in gorges and waterholes in Central Australia. On occasion they have been found in swimming pools. How they get there is unknown.

The only leaf-shaped water scorpion species in Australia is Laccotrephes tristis. There are other, sort-of leafy-looking species, like Austronepa and Goondnomdanepa, but they are not as broad, or don’t have as long breathing tubes.

Russell’ Yong, Entomology Australia “Invertebratology”, Facebook
Water Scorpion (Laccotrephes tristis), Alice Springs, NT
Water Scorpion (Laccotrephes tristis), Alice Springs, NT

The Water Scorpion pictured here was rescued from a salt-watered swimming pool in Alice Springs and relocated to a fish pond.

It is interesting to see the colour difference when we relocated the Water Scorpion from the swimming pool to the fish pond.


Many thanks to Russell’ Yong from Entomology Australia “Invertebratology”, Facebook group for assistance with identifying this Water Scorpion species.


  • Scientific classification
  • Kingdom: Animalia
  • Phylum: Arthropoda
  • Class: Insecta
  • Order: Hemiptera
  • Superfamily: Nepoidea
  • Family: Nepidae
  • Subfamily: Nepinae
  • Genus: Laccotrephes
  • Species: Laccotrephes tristis

Footnote & References

  1. Laccotrephes, https://en.wikipedia.org/wiki/Laccotrephes (last visited Dec. 23, 2021)
  2. Entomology Australia “Invertebratology”, Facebook group, https://www.facebook.com/groups/507004496955277