Hemiphileurus illatus
In 3 days ~20% in a week ~40%
Hemiphileurus illatus is a species of rhinoceros beetle in the family Scarabaeidae. Its range is the Southwestern United States. Its common name is the lesser triceratops beetle. As adults, this species is black with a pitted thorax and elytra. All six legs have short spines. They are 19 - 25 mm long.
Both sexes have a pair of horns but the females' are much smaller, more like bumps or short nubs. Unlike their close cousins, Phileurus truncatus, neither sex has the notable third horn. As larvae, they have cream-colored bodies and reddish-brown heads. They have a C-shaped posture, and move on their sides when above ground.
As pupae, they are exarate with the ability to move their abdominal segments. As pupation progresses, their joints, faces, and tips of their legs change from tan to dark brown. H. illatus is found in the Southwestern United States, primarily Arizona, Nevada, New Mexico, and California. It is found in urban and rural areas.
Adults are detritivores and scavengers. They eat fresh or rotting plant matter and other dead insects. In captivity, they will eat freshly-killed mealworms, fruits, and vegetables.They are... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saguaro National Park | 🇺🇸 United States |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Lesser Triceratops Beetle sighting in Saguaro National Park on a given day, based on 17 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 134th most-seen of the 354 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.
June to October
In those months about 10% of wildlife watchers report a Lesser Triceratops Beetle in Saguaro National Park on a given day, against under 5% in November to May, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Lesser Triceratops Beetle sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Only Saguaro National Park, in our data
Saguaro National Park is the only park on Wallace's Line with enough records to rate Lesser Triceratops Beetle sightings: about 10% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Lesser Triceratops Beetle is recorded against all the insects logged in Saguaro National Park (17 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.
