Passalidae is a family of beetles known variously as "bessbugs",[1] "bess beetles",[1] "betsy beetles"[1] or "horned passalus beetles". Nearly all of the 500-odd species are tropical; species found in North America are notable for their size, ranging from 20–43 mm, for having a single "horn" on the head, and for a form of social behavior unusual among beetles.

Bodies elongate-cylindrical and black overall; ventral surfaces may be covered with yellow setae. The head is narrower than the thorax, with antennae consisting of 10 antennomeres with a three-segment club. The elytra are elongate with parallel sides, and heavily striated.

They are subsocial (brood caring) beetles that live in groups within rotting logs or stumps.[2] The beetles will excavate tunnel systems within rotting wood where the females then lay their eggs.[3] They care for their young by preparing food for them and helping the larvae construct the pupal case. Both adults and larvae must consume adult feces which have been further digested by microflora for a time; an arrangement that might be described as a sort of external rumen.

In addition, they are also able to produce fourteen acoustical signals, more than many vertebrates. Adults produce the sounds by rubbing the upper surface of the abdomen against the hind wings. The larvae produce the sounds by rubbing the third leg against a striated area on the coxa of the second leg.

While the taxonomy of Nearctic species is well-known (four species in the US, and 90 in Mexico), bess beetles in other parts of the world need further study.

Of North American species, Odontotaenius disjunctus (synonym: Popilius disjunctus) is the familiar bessbug found throughout the eastern US and Canada, while O. floridanus has only been found in Florida on sand hills that used to be islands when Florida was flooded thousands of years ago. Ptichopus angulatus was recently discovered near the border of Mexico in Arizona. Its habitat is south to Colombia and it is commonly associated with the detritus chambers of leafcutter ant nests (Atta spp.). Two other species were reported from Arizona at the beginning of the 20th century, but have not been seen there since that time; they may have been brought from Mexico by a train hauling firewood.

Adult Odontotaenius disjunctus
Larva of Odontotaenius disjunctus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Superfamily: Scarabaeoidea
Family: Passalidae
Leach, 1815


many more
> 500 species

Selected species

  • Genus Aceraius
Aceraius laevicollis - Mindanao, Philippines
Aceraius laevicollis from under a rotten log in Mindanao, Philippines
Aceraius grandis
  • Genus Aulacocyclus
Aulacocyclus edentulus
  • Genus Ceracupes
Ceracupes arrowi
  • Genus Chondrocephalus
Chondrocephalus debilis
Chondrocephalus granulifrons
  • Genus Cylindrocaulus
Cylindrocaulus patalis
Didimus laevis
Didimus parastictus
  • Genus Heliscus
Heliscus tropicus
  • Genus Leptaulax
Leptaulax bicolor
  • Genus Odontotaenius
Odontotaenius disjunctus (patent-leather beetle)
Odontotaenius floridanus
Odontotaenius striatopunctatus
  • Genus Ogyges
Ogyges laevior
  • Genus Oileus
Oileus rimator
Passalus affinis
Passalus caelatus
Passalus elfriedae
Passalus inops
Passalus interruptus
Passalus interstitialis
Passalus jansoni
Passalus latifrons
Passalus pugionifer
Passalus punctatostriatus
Passalus punctiger
Passalus spiniger
Passalus unicornis
  • Genus Paxillus
Paxillus leachi
Paxillus pentataphylloides
Pentalobus barbatus
  • Genus Petrejoides
Petrejoides orizabae
  • Genus Popilius
Popilius eclipticus
  • Genus Proculus
Proculus burmeisteri
Proculus mniszechi
  • Genus Ptichopus
Ptichopus angulatus
  • Genus Publius
Publius agassizi
  • Genus Spasalus
Spasalus crenatus
Spurius bicornis
  • Genus Verres
Verres corticicola
Verres hageni
  • Genus Veturius
Veturius transversus

See also


  1. ^ a b c John L. Foltz (2001-07-08). "Family Identification. Coleoptera: Passalidae". University of Florida. Archived from the original on 2008-12-18.
  2. ^ "Generic Guide to New World Scarab Beetles-Scarabaeoidea-Passalidae Overview". Retrieved 2017-01-22.
  3. ^ "What Are Bess Beetles?". Education. Retrieved 2017-01-22.


External links

Aulacocyclus edentulus

Aulacocyclus edentulus is a beetle of the Passalidae family that occurs in Australia.


Bolboceratidae, the dor beetles, is a family of beetle. It was historically treated as a subfamily of the earth-boring dung beetles (family Geotrupidae), but has been considered a separate family since 1995. Some recent classifications have persisted in treating bolboceratids as a subfamily (e.g.) but these classifications are contradicted by recent phylogenetic studies of relationships indicating that bolboceratids are not closely related to geotrupids (e.g., that bolboceratids are more closely related to Pleocomidae and Passalidae).


Chahuis or xamoes are the common names given in Mexico to a variety of edible beetles within the insect order Coleoptera. The insects' common names in English are often "sticks worms", "rhinoceros beetle," or "grub".

The chahuis insects feed on species of the Mesquite tree.

Particularly appreciated are the larvae of the following families: Cerambycidae, Scarabaeidae, Melolonthidae, and Passalidae.


Didimus is a genus of beetles of the family Passalidae.

Odontotaenius disjunctus

The patent-leather beetle or "Bess Beetle" (Odontotaenius disjunctus) is a saproxylic beetle in the family Passalidae which can grow to just over an inch-and-a-half 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 1900's but remain a relatively unknown species within the diverse Coleoptera order.


Passalus is a genus of beetles of the family Passalidae.

Passalus inops

Passalus inops is a beetle of the Family Passalidae.

Passalus interruptus

Passalus interruptus is a beetle of the Family Passalidae.


Pentalobus is a genus of beetles in the family Passalidae.

Pentalobus barbatus

Pentalobus barbatus is a beetle species of the genus Pentalobus of the family Passalidae.

Petrejoides orizabae

Petrejoides orizabae is a beetle of the Family Passalidae.

Proculus burmeisteri

Proculus burmeisteri is a beetle of the Family Passalidae.

Ptichopus angulatus

Ptichopus angulatus is a beetle of the Family Passalidae.

Publius agassizi

Publius agassizi is a beetle of the family Passalidae, named in honor of Louis Agassiz.


Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed in this superfamily and some 200 new species are described each year. Its constituent families are also undergoing revision presently, and the family list below is only preliminary.


Spurius is a small genus of passalid beetles from Mesoamerica.

Spurius bicornis

Spurius bicornis is a beetle of the Family Passalidae.

Toxeutotaenius elfriedae

Toxeutotaenius elfriedae is a South American Betsy beetle of the family Passalidae.

Verres hageni

Verres hageni is a beetle of the Family Passalidae. It belongs to class insecta and its order is Coleoptera.

Extant Coleoptera families


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