Passalidae is a family of beetles known variously as "bessbugs", "bess beetles", "betsy beetles" 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. The beetles will excavate tunnel systems within rotting wood where the females then lay their eggs. 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.
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|
|> 500 species|
Aulacocyclus edentulus is a beetle of the Passalidae family that occurs in Australia.Bolboceratidae
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
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
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
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
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
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
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