The Poultry Private Eye

Kelly’s Field Notes

Common Name: Hister Beetles (hister is Latin for “actor”), Clown Beetles

Order: Coleoptera

Family: Histeridae

Genus: There are about 330 genera of hister beetles worldwide (Bug Guide, 2026).

Species Near You (There are about 4,000 species of hister beetles worldwide, about 500 or so in North America (Bug Guide, 2026): 

• Equal or Flat clown beetle (Hololepta aequalis) - found throughout central to the coastal eastern U.S. this beetle is notable for its very flat shape.

• Saprinus pensylvanicus - notable for its beautiful blue-green carapace, found throughout North America

• Red-spotted clown beetle (Margarinotus purpurascens) - found throughout western and eastern Europe into western Asia, this species has two prominent red spots on its carapace.

• Haeterius ferrugineus - known to hang out in ant nests. Though common in mainland Europe, it was not seen in the UK since 1920, a specimen was later found in a nest of slave maker ants (Formica sanguinea)* in 2012. This species is exclusively found within ant nests and feeds on dead and wounded ants, larvae, pupae, and mites etc. There is one instance of researchers noting the ants feeding the beetle (Brown, 2012).

• Poultryhouse pill beetle (Carcinops pumilio) -  poultryhouse hister beetles are used as biocontrol in poultry houses. Adults consume an average of 54 housefly larvae per day at 80º F. Hister larvae are also predaceous and highly aggressive (Rincon-Vitova Insectaries, 1999).

• Beetlebum (Nymphister kronaueri) - this beetle hitches a ride on army ants by attaching itself to the ant’s waist. First identified in 2014, it is found in Costa Rica (Kronauer, 2017).

*A quick note about slave maker ants, they are species of ants that steal the broods of other ants to supplement the work force in their nests. In the instance of the hister beetle example, the enslaved ants were silky ants (Formica fusca) and brown tree ants (Lasius brunneus)

Description: 

Hister beetles are all on the small side, about 1-10 mm (0.04-0.4 in) in length. They are shiny and while most are black, those that live with ants tend to be similar colors to their host ants. Unusual for beetles, their elytra (wing coverings) are short, leaving part of the abdomen exposed.

In some species, their front limbs are flat, toothed, and wide, used for digging. When disturbed they pull their limbs in to protect them. Because their elytra don’t cover their entire abdomen, hister beetles are flexible. When grabbed by a predator they curl slightly and clamp down on whatever they are standing on to avoid being pulled up.

Hister Beetle Biocontrol:

Hister beetles are often used as biocontrol in poultry operations. Adults consume an average of 54 housefly larvae per day at 80º F. Hister larvae are also predaceous and highly aggressive. Adult beetle densities can get as high as 250 beetles per quart of manure and 12 beetles per square inch of manure. Adults are tiny! So much so that 250 can fit in a milliliter (Rincon-Vitova Insectaries, 1999). Hister beetles are also used in the cattle industry to keep fly populations in the manure down, lowering disease risk for the cattle. This has been such an issue that the USDA imported several species from Africa, Java, Pakistan, Australia, and Asia to control face flies and horn flies in the early 1900’s (Fincher, 1914). You can currently buy Carcinops pumilio for poultryhouses, 2,000 beetles for $180.00 (Arbico Organics, 2026).

Hister Beetles and Forensic Entomology:

Hister beetles feed on fly eggs and maggots on decomposing remains, forensic entomologists can use the timing of their appearance to help identify when the body was placed at the crime scene (Fakoorziba et al., 2017). They arrive typically during the bloated and active decay stage. In forensic entomology, the estimated time that has elapsed since someone’s death is referred to as the post-mortem interval (PMI) (Weisensee et al., 2024).

Super Powers:

• Retractable appendages - hister beetles can tuck in their legs and antennae for defense

• Tough carapace - like most beetles, their tough carapace protects them from predators

• Play Dead (thanatosis) - a common trick among many arthropods, hister beetles will play dead when disturbed. This acting is what gives the family its name (hister is actor in Latin)

• Chemical Defense - if playing dead doesn’t work, some hister beetles produce noxious chemicals from glands in their abdomens

• Flight - while not the most aerodynamic of beetles, they can fly

• Speed - hister beetles are known for their quick run speeds

• Ant Friends - several species of hister beetles live with ants

References:

Brown, Alan. “Haeterius Ferrugineus Rediscovered after 92 Years Absence.” Worcestershire Record, Oct. 2012, www.wbrc.org.uk/worcrecd/33/Brown_Alan--Haeterius_ferrugineus_rediscovered_aft.html. Accessed 9 Apr. 2026.

‌“Carcinops Pumilio (Hister Beetles) Prevent Fly Outbreaks.” Https://Rinconvitova.com/Bulletins_product_htm/Carcinops%20pumilo.htm, Rincon-Vitova Insectaries, 1999. Accessed 9 Apr. 2026.

‌“Family Histeridae - Clown Beetles.” Bugguide.net, 2026, www.bugguide.net/node/view/6577.

Fincher, G. "Biological control of dung-breeding flies affecting pastured cattle." Great Plains Beef Cattle Handbook (1914).

Fakoorziba, M. R., et al. "Saprinus planiusculus (Motschulsky ‚1849)(Coleoptera: Histeridae), a beetle species of forensic importance in Khuzetan Province, Iran." Egyptian journal of forensic sciences 7.1 (2017): 11.

“Hister Beetle Carcinops Pumilio.” Arbico Organics, 2026, www.arbico-organics.com/product/hister-beetle-carcinops-pumilio/beneficial-insects-predators-parasites?srsltid=AfmBOor2-aX20paQQD6Gvijz30xkzbgwYDxfx3MDJwmJwdz4eG5JeqiW. Accessed 9 Apr. 2026.

‌Kronauer, Daniel. Newly Discovered Beetle Species Named after Rockefeller’s Daniel Kronauer. Rockefeller University, 13 Feb. 2017, www.rockefeller.edu/news/18619-newly-discovered-beetle-species-daniel-kronauer/. Accessed 13 Apr. 2026.

Weisensee, Katherine E., and Madeline M. Atwell. "Human decomposition and time since death: Persistent challenges and future directions of postmortem interval estimation in forensic anthropology." American Journal of Biological Anthropology 186 (2024): e70011.‌