Odontotaenius disjunctus
In 3 days ~20% in a week ~50%
Odontotaenius disjunctus, the patent-leather beetle or horned passalus, is a saproxylic beetle in the family Passalidae (bess beetles) which can grow to over 3 cm long, weigh 1-2 grams and are capable of pulling 50 times their own weight. They have been used to study several aspects of general family characteristics since the early 1900s but remain a relatively unknown species within the diverse Coleoptera order.
Odontotaenius disjunctus is most commonly found in climates with higher humidity, mainly in the warmer parts of both hemispheres, and also widely distributed in temperate North American forests. O. disjunctus beetles are usually found under, or inside, old logs or stumps and are rarely observed outside of their wooden habitats.
These beetles can be found in rotting logs, especially of oak and hickory. This specific locale offers unique benefits in regards to protection from predators and external abiotic factors such temperature and precipitation. There is a level of stability with the two factors mentioned, the water retention in the wood helps to keep temperatures stable while aiding in further decomposition of the log itself... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Congaree National Park | 🇺🇸 United States | |
| 2 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 3 | Shenandoah National Park | 🇺🇸 United States | |
| 4 | Point Pelee National Park | 🇨🇦 Canada | |
| 5 | Merritt Island National Wildlife Refuge | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Washington | 🇺🇸 United States | |
| 2 | Baltimore | 🇺🇸 United States | |
| 3 | Philadelphia | 🇺🇸 United States | |
| 4 | New York City | 🇺🇸 United States | |
| 5 | Houston | 🇺🇸 United States | |
| 6 | Dallas | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Horned Passalus Beetle sighting in Merritt Island National Wildlife Refuge on a given day, based on 17 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 73rd most-seen of the 189 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 50%, if each day is a fresh chance.
May and October
In those months about 20% of wildlife watchers report a Horned Passalus Beetle in Merritt Island National Wildlife Refuge on a given day, against under 5% in January–February, June–July and September, the lowest months.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Horned Passalus Beetle sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
5th of 5
Of the 5 parks where we can rate Horned Passalus Beetle sightings, Merritt Island National Wildlife Refuge ranks 5th at about 10%. The best odds are in Congaree National Park (United States, about 20%), Great Smoky Mountains National Park (United States, about 20%) and Shenandoah National Park (United States, about 10%).
Same order: Coleoptera
The closest relatives of the Horned Passalus Beetle that you can see in Merritt Island National Wildlife Refuge (order Coleoptera, Beetles) are Margined Leatherwing Beetle (about 10%), Asian Lady Beetle (about 10%) and Dark Flower Scarab (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Horned Passalus Beetle is recorded against all the insects logged in Merritt Island National Wildlife Refuge (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.
