Phoracantha semipunctata
In 3 days ~10% in a week ~30%
Phoracantha semipunctata, the Australian Eucalyptus longhorn, is a species of beetle in the family Cerambycidae. Native to Australia, it has now spread to many parts of the world, including practically all countries where tree species of Eucalyptus have been introduced. It has been classified as an invasive pest species of Eucalyptus outside Australia.
Within Australia, Phoracantha semipunctata primarily seeks for decaying trees and branches which have been critically impaired due to natural disasters. In other regions of the world, it inflicts critical damage upon introduced Eucalyptus trees. However, the damage inflicted by Phoracantha semipunctata may be seen as a positive factor in some regions, as Eucalyptus trees that are introduced are seen as invasive plant species imposing harm on the natural environment.
Phoracantha semipunctata are typically dark brown & beige in colour and are approximately similar in size measuring at around 2.3cm long. They are primarily active during the more temperate initial dusk hours, and are found in populations within host trees, which are predominantly male-oriented. These host trees are determined according to the suitability of adult mating and oviposition, and the viability of larvae development. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Blue Mountains National Park | 🇦🇺 Australia | |
| 2 | Garden Route National Park | 🇿🇦 South Africa | |
| 3 | Table Mountain National Park | 🇿🇦 South Africa |
Rare
Under 5% of wildlife watchers report a Common Eucalyptus Longhorn sighting in Blue Mountains National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 611th most-seen of the 789 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
February–March and September
In those months about 10% of wildlife watchers report a Common Eucalyptus Longhorn in Blue Mountains National Park on a given day, against under 5% in April–August and October–January, the lowest months.
Between 7 and 10 am
Across all the parks we cover, that three-hour window holds the most Common Eucalyptus Longhorn sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 3 parks where we can rate Common Eucalyptus Longhorn sightings, Blue Mountains National Park has the highest daily chance: under 5%. Next come Garden Route National Park (South Africa, under 5%) and Table Mountain National Park (South Africa, under 5%).
Same family: Cerambycidae
The closest relatives of the Common Eucalyptus Longhorn that you can see in Blue Mountains National Park (family Cerambycidae, Longhorn Beetles) are Amphirhoe sloanei (about 10%) and Tiger Longhorn (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Common Eucalyptus Longhorn is recorded against all the insects logged in Blue Mountains National Park (6 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.
