Laccotrephes tristis
Silhouette: PhyloPic
In 3 days ~20% in a week ~40%
Laccotrephes tristis is a species of water scorpion also commonly known as a toe-biter, that occurs Australia-wide and is part of the family Nepidae. They are an aquatic predatory insect that breathe air. Australian water scorpions inhabit shallow stagnant water, part of freshwater creeks, waterholes and gorges.
Laccotrephes tristis is brownish in colour with a broad oval shaped, flat body, at a length of 11–45 mm (0.43–1.77 in). Adult males have smaller body lengths (26–32 mm (1.0–1.3 in)) than females (31–35.5 mm (1.22–1.40 in)).
Australian water scorpions have six legs; the front two forelegs are pincer-like used for grasping aquatic prey and the hind legs are used for moving about. They have a relatively short, pointed head and small eyes. They have antennae with 3 segments and a finder-like projection, hidden in a groove beneath the eyes.
Water scorpions get their name from the tail-like respiratory siphon located on the end of their abdomen. The respiratory siphon is at least three quarters the length of the body. They use this siphon to transport air (a bit like a snorkel). A water scorpion breaths air from an air bubble trapped beneath its wings, which includes... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Uluru-Kata Tjuta National Park | 🇦🇺 Australia | |
| 2 | Grampians National Park | 🇦🇺 Australia | |
| 3 | Blue Mountains National Park | 🇦🇺 Australia |
With luck
About 10% of wildlife watchers report an Australian Water Scorpion sighting in Grampians National Park on a given day, based on 5 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 122nd most-seen of the 148 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
February
In that month about 20% of wildlife watchers report an Australian Water Scorpion in Grampians National Park on a given day, against under 5% in May–September and November–December, the lowest months. That is one of Grampians National Park's driest months, with about 20 mm of rain against 85 mm in October.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Australian Water Scorpion sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
2nd of 3
Of the 3 parks where we can rate Australian Water Scorpion sightings, Grampians National Park ranks 2nd at about 10%. The best odds are in Uluru-Kata Tjuta National Park (Australia, about 20%).
Same order: Hemiptera
The closest relatives of the Australian Water Scorpion that you can see in Grampians National Park (order Hemiptera, True Bugs, Hoppers, Aphids, and allies) are Red Jewel Bug (about 40%), Green Grocer (about 30%) and Redeye Cicada (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Australian Water Scorpion is recorded against all the insects logged in Grampians National Park (5 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
