Bess Beetle Life Cycle: A Fascinating Journey Explored

Bess beetles, also known as Betsy beetles or patent leather beetles, lead quite intriguing lives.

These fascinating creatures are primarily found in rotting wood, where they play an essential role in recycling decaying material.

While engaging in this process, they pass through various stages in their life cycle, undergoing a complete metamorphosis.

The bess beetle life cycle starts with the egg, which typically hatches within 7 to 10 days.

Upon hatching, the larval stage begins and represents a crucial period in the beetle’s development.

Bess Beetle Life Cycle
Bess Beetle

During this time, adult bess beetles assist their babies, or larvae, by chewing on the wood first to help them consume it.

As we delve further into their life cycle, it’s fascinating to observe how each stage contributes to the overall growth and survival of these captivating insects.

Bess Beetle Life Cycle

Eggs and Larvae

Bess beetles, also known as Betsy beetles and patent leather beetles, lay their eggs in rotting wood.

After hatching, the larvae begin feeding on the decomposing wood.

The Bess beetle life cycle consists of four stages:

  • Egg
  • Larva
  • Pupa
  • Adult

Comparing Bess beetle life stage durations:

Life StageDuration
Egg7 to 10 days
LarvaVaries
PupaVaries
Adult1 to 2 years

Pupa

Following the larval stage, bess beetles enter the pupal stage.

The pupa forms a protective shell in which the beetle undergoes metamorphosis, transitioning from its larval form to an adult.

Eastern Bess Beetle Larva. Source: Katja Schulz from Washington, D. C., USACC BY 2.0, via Wikimedia Commons

Adult Beetle

Adult bess beetles are approximately 1 ½ inches (4 cm) long.

Once fully developed, they continue to live in rotting wood, helping to recycle nutrients back into the environment.

Reproduction and Social Behavior

Mating

Bess beetles (family Passalidae) exhibit unique reproductive behavior.

Males and females form monogamous pairs and mate within their established adult gallery, usually inside rotting logs.

During courtship, the male strokes his antennae and front legs on the female to initiate mating.

Mating highlights:

  • Monogamous pair bonding
  • Mating occurs in adult galleries

Parental Care

Bess beetles exhibit a cooperative brood care system, with both parents taking part in caring for their offspring.

This rare behavior in insects includes provisioning food and maintaining nest hygiene.

Communication through Stridulation

Bess beetles communicate using sound, specifically stridulation.

Adults and larvae alike produce these sounds by rubbing body parts together.

This mode of communication plays a vital role in maintaining their social structure and coordinating behaviors, such as resource sharing and group defense.

Bess Beetles

Conclusion

Bess beetles, also known as Betsy beetles or patent leather beetles, thrive in decaying wood, playing a pivotal role in recycling organic material.

Their life cycle encompasses stages from egg to adult, with a unique cooperative brood care system where both parents assist their offspring.

Communication through stridulation, or sound production, is vital for their social interactions. Morphologically, they possess a hard, shiny exoskeleton and distinct differences between males and females.

Their ecological significance and unique behaviors make them a subject of interest for entomologists and nature enthusiasts alike.

Reader Emails

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

Letter 1 – Bess Beetle

Hello,
We love your website! We found this beetle this morning and haven’t figured out what it is yet. My son found it under a log near his friend’s house; we live in Charlotte, North Carolina.

The beetle had a lot of orange ‘fur’ on its legs and under body. It had cool antennae not really visible in the photo and very strong jaws that looked like they could give a good bite!

The beetle also made a little hissing sound when interfered with. Sorry the picture is so out of focus, hoping you can help us identify this little guy. Thanks!
Eric

Hi Eric,
Your beetle is a Bess Beetle in the family Passalidae and the genus Odontotaenius. Bess Beetles are also called Patent Leather Beetles and they are rather unique in the beetle world because of their subsocial lifestyle. BugGuide indicates:

“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. See Generic Guide to New World Scarab Beetles for more details.”

Letter 2 – Bess Beetle

what is this
I found this beetle in some chunks of wood. They had eaten holes into the wood and looks as though they finely chew the wood up into sawdust. They are very dark brown or black, very shiny, have pinchers in the front and attacked the stick that I had put in front of them.

They are about 1′-1 – 1/14 inch long, very hard shell, looks like antenna on front of head, are segmented between the head and body. Attached are 2 photos of one of them. I have never seen them in my yard before. If you can tell me what they are I would appreciate it. Thank you.
C.L. Valentino

Hi C.L.,
We love when we get a photo of a Bess Beetle for identification, because they are such fascinating insects. Bess Beetles, Odontotaenius disjunctus, are also called Bess Bug, Betsy Beetle or Bug, Patent Leather Beetle, Peg Beetle and Horned Passalus. Here is what BugGuide has to say:

“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 prechewed 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. Adults are found at lights on occasion, despite statements in several sources. They may disperse by walking, but have been seen in Durham, North Carolina, to open elytra and fly briefly under lights (pers. observation, P Coin).

A nuptial flight has also been observed (MacGown and MacGown, 1996). Both adults and larvae make noises by stridulation, and this is said to serve as communication between them. Adults also stridulate when picked up, and especially, blown on. Stridulation mechanism of adults by rubbing abdomen against the wings. Larvae stridulate with reduced third pair of legs–these scratch against other legs. “

Letter 3 – Bess Beetle

Bess Beetle
Location:  Spencer, TN
October 13, 2010 6:02 pm
Hello!
First of all, I LOVE your website. I came across it about three years ago, and it has been quite useful for me in identifying the House Centipede, the Micrathena Spider, the female Velvet Ant, the female Dobsonfly, and most recently (today) the Bess Beetle.

I went camping last weekend and found this ’little’ guy on our firewood. I quickly scooped him into a box and put him on a tree away from the campsites (and away from people).

Of course I took a couple photos before letting him go on his way, so I have two photos for you. One with him next to my hand for size comparison (I have long hands, so he was right at 1.5 inches), and another close-up in front of his face. Enjoy!
Signature:  Sarah

Bess Beetle

Hi Sarah,
Thanks for your kind letter.  We love Bess Beetles, also known as Patent Leather Beetles, because of their complex family structures where the larvae are cared for by the adults. 

We wish we were not late for work or we would elaborate more on this posting.  We hope our readership will search for Bess Beetle postings in our archive to read more about these fascinating social insects.

Letter 4 – Bess Beetle

Jerusalem Beetle
Location: Lyndhurst, NJ
July 6, 2011 8:47 pm
I was visiting a friend a friend one night, and I almost made unnecessary carnage out of this little creature.
We promptly moved it out of harms way, and had a little photo shoot with it. I think I identified it correctly as a Jerusalem beetle or patent-leateher beetle.
I didn’t see to many photos of this beetle around the site so I wanted your input.
Thanks
Signature: Christina McGrath

Bess Beetle

Hi Christina,
You have correctly identified this as a Patent Leather Beetle, but we were not familiar with the name Jerusalem Beetle and we are curious where you found that name.  Beetles in the family Passalidae have many other common names including Bess Beetle, Betsy Beetle, Peg Beetle, Horn Beetle and Bess Bug. 

These are fascinating creatures and they have the distinction of being one of the few beetles that actually care for their young.  Other beetles that are known to care for their young are Dung Beetles and Burying Beetles, though Bess Beetles have a more pronounced family bond and they actually appear to communicate audibly with one another.

When I was searching to identify it on the web, it brought me to this wikipedia page http://en.wikipedia.org/wiki/Patent-leather_beetle I was not sure if it was accurate (as wikipedia is not a reliable source) that is why I submitted this to your site, which I adore by the way! Not a fan of touching bugs, but I love to look at them!
Thank You for your help!!!

Letter 5 – Bess Beetle

Subject:  What beetle is this?  It hisses!
Geographic Location of the Bug:  Smith Mountain Lake, Virginia
Date:  October 19, 2017
Time:  10:39:19 AM EDT
Hi Dan,
Found this beetle in my barn in S.M.L. Va. Very pretty, shinny, and if you pick it up it hisses. So kool. Would you please let me know what kind of beetle this is? Love your website, thanks for all you and staff do to educate everyone!
Thanks Hairy Mary

 

Bess Beetle

Dear Hairy Mary,
This is a Bess Beetle in the family Passalidae.  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. … 

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.”  The hissing sound you heard was the stridulation.

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.

Leave a Comment