Bug FAQDiabolical Ironclad Beetle
Phloeodes diabolicus · Order: Coleoptera · Family: Zopheridae
The diabolical ironclad beetle has a flat, low-profile body and a very tough shell that can withstand forces over 149 N (about 15 kg). It lives under the bark of decaying oak trees in California and Baja California, feeding on fungi and rotting wood. Adults are flightless and can live up to eight years, which is unusually long for beetles.
Source: Wikipedia
How to recognize it
The beetle’s flattened shape and low-to-the-ground profile make it hard to crush. Its thick, interlocking elytra and lateral supports can bear more than 149 N of force.
Source: Wikipedia
Where it lives
It lives most often beneath the bark of decomposing oak trees.
Source: Wikipedia
What it eats
It feeds on fungi that grow under rotting tree bark. It is a generalist decomposer that eats rotten wood and the fungi on it from many tree and shrub species.
Source: Wikipedia
Life cycle
The beetle is flightless and adults can live up to eight years. Like other Zopherini, it undergoes complete metamorphosis (holometabolous).
Source: Wikipedia
Lookalikes
It shares its range with the sister species Nosoderma plicatum, which is reproductively isolated.
Source: Wikipedia
Where it is found in the US
Recorded in 7 of 51 states and DC. Most records: California, Kansas, Oregon, Arizona, Washington, Nevada, New Mexico.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What does the diabolical ironclad beetle eat?
It eats fungi growing under rotting bark and the decaying wood itself.
Source: Wikipedia
Where is this beetle found?
It lives under bark of dead oak trees in California and Baja California.
Source: Wikipedia
How long do adult beetles live?
Adults can live up to eight years, which is long for beetles.
Source: Wikipedia
Can this beetle be crushed easily?
No, its tough, interlocking shell can resist forces over 149 N (about 15 kg).
Source: Wikipedia
Same family (Zopheridae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Phloeodes_diabolicus
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.