Do Bess Beetles Bite? Uncovering the Truth About These Insects

Bess beetles, also known as betsy beetles or patent leather beetles, are insects belonging to the family Passalidae.

They are predominantly found in tropical regions, with only two species inhabiting temperate climates, such as the eastern United States and Japan [1].

These beetles play a crucial ecological role, as they help recycle rotting wood in their habitats [2].

Do Bess Beetles Bite
Bess Beetles

Do Bess Beetles Bite?

Although Bess beetles might appear intimidating due to their size, typically 1 ½ inches (4 cm) long, they are not known to be harmful to humans or pets [3].

Bess beetles generally spend their time breaking down rotting wood, and they don’t have a tendency to bite humans or pets.

So, there’s no need to worry about their bites, as these beetles are more focused on their ecological niche than on being a threat to anyone.

Bess Beetle Characteristics

Physical Features

Bess beetles, also known as Odontotaenius disjunctus, belong to the insect order Coleoptera. They exhibit some unique features:

  • Size: Adults are about 1 ½ inches (4 cm) long.
  • Exoskeleton: They have a shiny, dark brown to black exoskeleton.
  • Elytra: Their elytra (hardened front wings) are smooth and glossy.
  • Horn: These beetles possess a single horn on their head.
  • Mandibles: They have robust, strong mandibles used for chewing wood.
  • Antennae: Their antennae are short and club-shaped.

Bess beetles are not rhinoceros beetles, but they share some similarities, such as the presence of a horn on their head.

Social Behavior

Bess beetles are gentle insects, known for their social behavior. They live in colonies within decaying logs, where they nurture their larvae.

Adults and larvae work together to break down wood, recycling nutrients back into the ecosystem. Bess beetles are not known for biting humans.

Stridulation Sounds

One of the most fascinating characteristics of bess beetles is their ability to produce squeaking sounds, also known as stridulation.

They create these sounds by rubbing body parts together, mainly using ridges and a scraper found on their exoskeleton.

These sounds are used to communicate within the colony, and can be heard if the beetle is handled or disturbed.

Bess Beetle

Bess Beetle’s Life Cycle and Habitat

Life Cycle

Bess beetles, also known as bessbugs or patent leather beetles, have a complete metamorphosis during their life cycle.

  • Egg stage lasts for 7 to 10 days
  • Larvae (which can produce begging calls using their hind and middle leg pairs) feed on rotting wood
  • Pupation occurs before adulthood

Preferred Habitat

Bess beetles, specifically the Odontotaenius disjunctus species, are native to the eastern U.S. and prefer inhabiting hardwood logs in deciduous woodlands.

Key features of their ideal habitat include:

  • Oak, hickory, and maple trees for a food source
  • Decaying wood to house microflora (necessary for their digestion)
  • Damp hardwood logs for laying their eggs

Bess beetles are usually non-aggressive and don’t pose a threat to humans. Their diet consists of decaying wood, making them important for maintaining a healthy ecosystem.

Comparing Bess Beetles and Stag Beetles

FeatureBess BeetleStag Beetle
Size1 ½ inches long1 to 4 inches long
Food SourceDecaying woodDecaying wood for larvae, adults may consume nectar
InteractionNon-aggressiveNon-aggressive
LegsHind legs used for larval communicationLarge mandibles used in fighting

Bess Beetles and Their Diet

Primary Food Sources

Bess beetles mainly feed on rotting wood. Both adult beetles and their larvae consume decaying wood, which comes mostly from:

  • Deciduous trees
  • Woody debris

They prefer softer wood that has been partially broken down by fungi and bacteria.

Role in Ecosystem

Bess beetles play a crucial role in forest ecosystems as decomposers.

They help in breaking down wood and returning nutrients to the environment. Here are some key facts about their role:

  • Convert wood into simpler materials
  • Release nutrients back into the soil
  • Aid in the natural recycling process

Bess beetles also contribute to the overall biodiversity of the forest by making dead wood a habitable environment for various microorganisms.

Mite Relationship

These beetles have a unique relationship with mites. Mites can often be found living on the exoskeleton of bess beetles, and they engage in a symbiotic relationship where both species benefit. Here’s how this relationship works:

  • Mites feed on fungi and bacteria that grow on the beetle’s poop
  • Cleaning the beetles can help prevent harmful microflora growth
  • Beetles provide mites with a consistent food source and transportation

This fascinating relationship illustrates the complexity of the forest ecosystem, where diverse species interact to promote a more stable environment.

Bess Beetles as Pets

Caring for Bess Beetle Pets

Bess beetles, also known as Horned Passalus or Patent Leather Beetles, are unique and low-maintenance pets.

To care for a Bess beetle as a pet, you should:

  • Provide a spacious and well-ventilated enclosure
  • Mimic their natural habitat with rotten wood, soil, and some leaves
  • Maintain a slightly damp environment
  • Feed them fruits and vegetables occasionally

Potential Health Risks

Although Bess beetles pose minimal risks, it is essential to be aware of potential health concerns. Some issues to consider include:

  • Mites: Bess beetles may carry mites that can pose a risk to the beetles’ health and the cleanliness of their enclosure. Routine cleaning and inspection can help mitigate mite infestations.
  • Allergic reactions: Some people may be allergic to Bess beetles or their secretions. If you experience any itching, rashes, or respiratory issues after handling your beetle, consult a medical professional.
  • Provoked bites: While Bess beetles are generally docile, they may bite if provoked. Their bites are not venomous, but they can be painful.

Here’s a comparison table of some common pet invertebrates:

Pet InvertebrateStrengthsWeaknesses
Bess beetlesLow-maintenance, docileCan bite if provoked
SpidersFascinating to observe, varietyBites can be venomous, harder to handle
TicksNot typically kept as petsCan carry diseases, parasitic

In conclusion, Bess beetles (Horned Passalus) can make interesting and low-maintenance pets. Ensuring a proper habitat and being aware of potential health risks can make them a unique addition to your home.

Bess Beetle

Notable Bess Beetle Species

Horned Passalus

  • Odontotaenius disjunctus
  • Commonly found in decaying wood

The Horned Passalus is a species of beetle within the Bess beetle family, Passalidae. Its scientific name is Odontotaenius disjunctus. They can be found in decaying wood habitats, such as rotten logs and stumps in deciduous woodlands. Biting is unlikely as they are primarily detritivores, feeding on decaying wood.

Patent Leather Beetle

  • Odontotaenius disjunctus
  • Also known as Betsy Beetle

The Patent Leather Beetle is another name for the Horned Passalus. This beetle is also referred to as Betsy Beetle, Bessbug, Jerusalem Beetle, Horn Beetle, and Peg Beetle. These beetles are characterized by their shiny black color and small “horn” on top of the head.

Comparison:

FeatureHorned PassalusPatent Leather Beetle
Scientific NameOdontotaenius disjunctusOdontotaenius disjunctus
Common NamesHorned Passalus, Bess BeetlePatent Leather Beetle, Betsy Beetle, Bessbug, Jerusalem Beetle, Horn Beetle, Peg Beetle
HabitatDecaying woodDecaying wood
MouthpartsChewingChewing
Role in EcosystemDetritivore (feeds on decaying wood)Detritivore (feeds on decaying wood)

Though these beetles share many similarities with scarab beetles, stag beetles, and rhinoceros beetles, they are unique in having a small horn and living in decaying wood habitats.

They use their chewing mouthparts to feed on decaying wood and ward off intruders. However, biting humans is uncommon and not a significant concern.

Conclusion

Bess beetles are integral to forest ecosystems, aiding in the decomposition of rotting wood. Despite their intimidating size, they pose no threat to humans or pets.

These beetles are characterized by their shiny black exoskeleton, a unique horn on their head, and robust mandibles.

They exhibit social behaviors, living in colonies and nurturing their larvae.

One of their most intriguing features is their ability to produce squeaking sounds, known as stridulation, used for communication.

Native to the eastern U.S., they prefer hardwood logs in deciduous woodlands, emphasizing their ecological importance.

Footnotes

  1. https://uwm.edu/field-station/horned-passalus-beetle/

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Bess Beetle

Subject: Found In Mulch
Location: Eastern Virginia
March 27, 2013 7:32 pm
I found this guy in the pile of mulch I was overturning in Norfolk, VA. He was about the size of my thumb, and I’m not a very big person.
Signature: D’Ann

Bess Beetle
Bess Beetle

Hi D’Ann,
This is a Bess Beetle,
Odontotaenius disjunctus.  The Bess Beetle is also called “Bess Bug, Betsy Beetle or Bug, Patent Leather Beetle, Peg Beetle” according to BugGuide.  Bess Beetles are found in rotting logs and they are rather unique among beetles as they care for their young.  Here is the life style description from BugGuide

“Lifestyle of this family is unique for beetles: live in small colonies where larvae are cared for by adults of both sexes. Long life cycle, apparently more than one year. Larvae eat a rotting wood pre-chewed by adults. (Some references state larvae eat feces of adults as well.) Larvae and adults also cannibalize injured larvae.”

Thank you very much!  More requests to follow as I continue to explore the local area.

Letter 2 – Bess Beetle

Subject: Large Black Scarab or Beetle Found – What Is It?!
Location: Raleigh, NC
June 27, 2013 2:27 pm
We found this just outside our garage yesterday. I think it might be dead because it hasn’t moved in the last 24 hours. I’ve never seen anything quite like this in size. I guess we really do grow ’em big here in the South. Anyone know what it might be?
Signature: Melanie

Bess Beetle
Bess Beetle

Dear Melanie,
This is a Bess Beetle or Patent Leather Beetle,
Odontotaenius disjunctus.  Bess Beetles have one of the most fascinating life cycles of any beetle.  According to BugGuide

“Lifestyle of this family is unique for beetles: live in small colonies where larvae are cared for by adults of both sexes. Long life cycle, apparently more than one year. Larvae eat a rotting wood pre-chewed by adults. (Some references state larvae eat feces of adults as well.) Larvae and adults also cannibalize injured larvae. …

Both adults and larvae stridulate, and this is said to serve as communication between them. Adults also stridulate when picked up, and especially, blown on. Adults stridulate by rubbing abdomen against the wings. Larvae stridulate with reduced third pair of legs–these scratch against other legs.” 

Stridulation is a fancy word for the act of producing a squeaking sound, so Bess Beetles squeak.  Bess Beetles are not actually Scarabs, but they are classified along with Scarabs and Stag Beetles into the superfamily Scarabaeoidea.

Letter 3 – Bess Beetle

Bess Beetle
Bess Beetle

Subject: Beetle Variant
Location: Reston, VA
October 14, 2014 11:27 am
Hello! I have enjoyed several of your posts helping to identify bugs. A friend of mine found this beetle in in October in her garden, Northern Virginia. She raises Monarchs and wants to find out if this one is one of the caterpillar hunters – or other threat to butterfly life.

It does not appear to be a ‘hunter’ and nor does it seem to match the photos I saw of the plain ground beetles. Look at the gold/orange coloring on legs and antennae.

It also doesn’t seem to have the extended head of a ‘big head ground beetle’. We would like to know what variety it is and if it is friend or foe to our butterfly friends. Thank you so much!
Signature: many thanks, L Phillips

Dear L. Phillips,
Tell your friend this Bess Beetle in the genus
Odontotaenius whose identity we verified on BugGuide, is no threat to the Monarchs.  Caterpillar Hunters like the Fiery Searcher are very different looking.  Members of the Bess Beetle Passalidae care for their young and they feed on rotting wood. 

According to BugGuide:  “Lifestyle of this family is unique for beetles: live in small colonies where larvae are cared for by adults of both sexes. Long life cycle, apparently more than one year. Larvae eat a rotting wood pre-chewed by adults. (Some references state larvae eat feces of adults as well.) Larvae and adults also cannibalize injured larvae. 

Adults reported to fly very seldom, however they are capable of flight, contrary to statements in some sources. Adults are found at lights on occasion. They may disperse by walking, but have been observed flying under lights (image), and they are sometimes taken in light traps (MacGown and MacGown, 1996).

A nuptial flight has been observed in Mississippi, with a group of 12-15 individuals flying at dusk, and one pair even mating in flight (MacGown and MacGown, 1996). Mating is also observed in the tunnels ….  Both adults and larvae stridulate, and this is said to serve as communication between them.

Adults also stridulate when picked up, and especially, blown on. Adults stridulate by rubbing abdomen against the wings. Larvae stridulate with reduced third pair of legs–these scratch against other legs.”  Our editorial staff spent many family holidays in Reston in the early 1970s.

Letter 4 – Bess Beetle

Subject: stag beetle like with single forehead protrusion
Location: Chapel Hill, NC, central piedmont of Chapel Hill
March 17, 2016 11:46 am
Found this guy yesterday walking on some moss in a damp, shady area, about midday. 1 1/2 inches long, with a single hose-bib like protrusion on its forehead. It was slow and not aggressive.

I have posted a short video of it at http://curiousneedleworks.com/2016/03/17/marching-beetle-for-march/, in case you would like to see it move.


If I could get a genus, that’d be enough to keep me happy. I’ve got it down to scarabaeoidea, but can’t tell beyond that. I think it might be a stag beetle.
Thanks for doing this!
Signature: Jessica

Bess Beetle
Bess Beetle

Dear Jessica,
Though it resembles a Stag Beetle, this Bess Beetle, Peg Beetle or Patent Leather Beetle in the family Passalidae  is a social beetle with a family structure in which both parents care for and communicate audibly with the grubs.  According to BugGuide

“Adults reported to fly very seldom, however they are capable of flight, contrary to statements in some sources. Adults are found at lights on occasion. They may disperse by walking, but have been observed flying under lights (image), and they are sometimes taken in light traps (MacGown and MacGown, 1996).

A nuptial flight has been observed in Mississippi, with a group of 12-15 individuals flying at dusk, and one pair even mating in flight (MacGown and MacGown, 1996).”

Letter 5 – Bess Beetle

Subject:  My New Friend
Location:  Holly Springs, MS
September 21, 2017 5:41 PM
Hi Daniel!
I was picking Magnolia tree seeds off the ground and made a new friend. LoL
Hope you’re having a great bug day!  Thank you for all you do. Your public adores your website!
Stephanie Berry
Aka previous bug queen

Bess Beetle

Dear Stephanie, AKA bug queen,
We love that you get a manicure and don your jewelry prior to doing yard work.  This awesome beetle is a Bess Beetle in the family Passalidae.  According to BugGuide:  “Unusual (for beetles) subsocial lifestyle. Adults and larvae live together in family groups in galleries excavated in rotting wood by adults. Adults care for larvae, and actively feed them prechewed food. Both adults and larvae stridulate, which is used for communication within the group.”

Bess Beetle
Thank you for getting back to me. I love you and your website. Critters of all kinds are special to me!
Have a great weekend, my fav bug man!
Steph

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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