Bug FAQRed Flour Beetle
Tribolium castaneum · Order: Coleoptera · Family: Tenebrionidae
Also called: Ferrugineous flour beetle, Rust-red Flour Beetle, red grain beetle
Source: Wikipedia
Adult red flour beetles are tiny, about 3 to 4 mm long, and are uniformly rust-brown or black, sometimes with a darker head and pronotum. They originate from Indo-Australian regions and live mainly in heated indoor spaces where they infest grain, flour, cereals, pasta, biscuits, beans and nuts. Hermetic storage for about 12 days can kill all of them, making airtight containers an effective control method.
Source: Wikipedia
How to recognize it
The head and pronotum may be a shade darker than the rest of the body.
Source: Wikipedia
Size
Adults measure roughly 3 to 4 mm (about 1/8 inch) in length.
Source: Wikipedia
Is it a pest in the house?
They are a worldwide pest of stored food products and are used as a model organism in research.
Source: Wikipedia
How to get rid of it
Hermetic (airtight) storage for 12 days caused 100 % mortality, making it an effective control method.
Source: Wikipedia
Where it lives
They are less able to survive outdoors and are most common in indoor heated environments.
Source: Wikipedia
What it eats
They feed on stored grain and other pantry foods such as flour, cereals, pasta, biscuits, beans and nuts.
Source: Wikipedia
Life cycle
Adults can live for more than three years.
Source: Wikipedia
Where it comes from
Their native range is Indo-Australia.
Source: Wikipedia
Lookalikes
Closely related beetles like Gnatocerus cornutus share a similar pest status in stored products.
Source: Wikipedia
Where it is found in the US
Recorded in 34 of 51 states and DC. Most records: California, Kentucky, Arizona, New Mexico, Kansas, Ohio, Texas, Florida.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
How do I get rid of red flour beetles?
Store flour and other pantry items in airtight containers; hermetic storage for about 12 days will kill all the beetles.
Source: Wikipedia
What do red flour beetles look like?
They are tiny (3 to 4 mm), uniformly rust-brown, brown or black, with the head and pronotum sometimes darker.
Source: Wikipedia
Where are red flour beetles from?
They originated in the Indo-Australian region and now live worldwide in heated indoor spaces.
Source: Wikipedia
Same family (Tenebrionidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Red_flour_beetle
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.