Pleasing Fungus Beetle: All You Need to Know in One Quick Guide

Pleasing Fungus Beetles are fascinating insects often found in wet, forested areas. They come in various sizes and colors, with some species boasting vibrant hues such as blue with black spots. These beetles thrive on feeding on fungi, making them common residents of rotting, downed logs. Due to their preference for fungi, they play a valuable role in breaking down decaying organic matter and supporting the ecosystem.

Some Pleasing Fungus Beetles measure between 2.0 to 3.5 mm, while others can be as large as 14.0 to 22.0 mm. Their shiny exoskeletons can exhibit varying shades and patterns, such as black with yellowish-orange bands. The life cycle of these beetles includes a larval stage that typically lasts only a few days before they mature into the captivating adults we recognize.

In this article, we’ll explore the unique characteristics of Pleasing Fungus Beetles, including their habitat, diet, and role in the environment. We’ll also delve into their fascinating life cycle, explaining how these intriguing insects transform from larvae to striking, colorful adults. So, gear up to uncover the mysteries of Pleasing Fungus Beetles and their importance in the natural world.

Biology and Taxonomy of Pleasing Fungus Beetles

Family Erotylidae

Pleasing Fungus Beetles belong to the family Erotylidae, which consists of beetles that feed primarily on fungi. They are known for their distinctive, often striking colorations. The family is diverse, with over 3,500 species worldwide.

Genera Megalodacne and Pseudischyrus

Two genera of Pleasing Fungus Beetles are Megalodacne and Pseudischyrus. Members of Megalodacne are elongate oval in shape, ranging from 14 to 22 mm in length, and adorned with shiny black and contrasting yellowish-orange bands on their forewings [1(https://content.ces.ncsu.edu/imegalodacnei-pleasing-fungus-beetles)]. Pseudischyrus beetles range in size from 2 to 3.5 mm long and have an egg-shaped body [2(https://entnemdept.ufl.edu/creatures/misc/beetles/pleasing_fungus_beetles.htm)].

Some features of Megalodacne and Pseudischyrus beetles:

• Megalodacne:
  • Elongate oval shape
  • 14 to 22 mm long
  • Shiny black with yellowish-orange bands
• Pseudischyrus:
  • Egg-shaped body
  • 2 to 3.5 mm long

Order Coleoptera and Superfamily Cucujoidea

Pleasing Fungus Beetles belong to the order Coleoptera, the largest order of insects with over 350,000 known species worldwide. Coleoptera includes diverse beetles like ladybugs, weevils, and fireflies. Pleasing Fungus Beetles are within the superfamily Cucujoidea, which encompasses around 10 different families of beetles.

Comparison Table:

Keep in mind that taxonomy is not set in stone and is subject to change as new scientific discoveries are made.

Physical Description and Varieties

Gibbifer Californicus

• Grayish-blue body
• Black spots on the elytra

Gibbifer Californicus is a type of pleasing fungus beetle that is characterized by its grayish-blue body and black spots on its elytra (wing covers).

Megalodacne Heros

• Shiny black or blue body
• Yellowish-orange bands

The Megalodacne Heros, on the other hand, has a shiny black or blue body with contrasting yellowish-orange bands on its forewings¹.

Colors and Patterns

Pleasing fungus beetles exhibit a variety of colors and patterns:

• Blue with black spots
• Shiny black with yellowish-orange bands

The colors and patterns of pleasing fungus beetles can vary depending on the species, such as the blue with black spots found in Gibbifer Californicus or the shiny black with yellowish-orange bands present in Megalodacne Heros¹.

Distribution and Habitat

North America Locations

Pleasing Fungus Beetles can be found in various locations across North America:

• California: They are often seen in moist, forested areas.
• Colorado, Wyoming, Kansas: Higher elevations provide ideal habitats.
• Arizona, New Mexico: Wet regions serve as suitable breeding grounds.

Example: In Florida, many species are less than 10 mm in length.

Mexican Varieties

Mexican Pleasing Fungus Beetles are also quite diverse:

• Adapted to various environments.
• Often found in tropical rainforests.

Bat Roost Habitats

Another surprising habitat for these beetles is inside bat roosts:

• Feed on bat guano for nutrients.
• Benefit from the protection provided by the bats.

Key Characteristics of Pleasing Fungus Beetles:

• Elongate-oval or egg-shaped body.
• Range in size from 2.0 to 22.0 mm long.
• Feed on fungi and rotting logs.

Example: The most common species in U.S. National Park Service is blue with black spots.

Diet and Relationship with Fungi

Feeding on Bracket Fungi

Pleasing Fungus Beetles primarily feed on fungi, particularly bracket fungi. These beetles can be found on rotting, downed logs where fungi are abundant¹.

Examples of bracket fungi include:

• Ganoderma applanatum
• Trametes versicolor
• Fomes fomentarius

Role in Pest Control

Pleasing Fungus Beetles offer a role in pest control since they help control certain fungal pests². Their feeding habits help regulate fungi populations, which can sometimes become invasive and damaging to plants.

Pros:

• Regulate fungi populations
• Prevent invasive fungi growth

Cons:

• Limited to specific fungal species
• Effectiveness depends on beetle population

Reproduction and Life Cycle

Laying Eggs

Pleasing Fungus Beetles lay their eggs on rotting vegetation or near fungi, providing a food source for their larvae. They typically lay a small number of eggs at a time, often in clusters.

Larval Stage

Once the eggs hatch, the larvae emerge and begin to feed on fungi. These larvae have a brief life span, only lasting a few days before entering the pupal stage.

• Features of larvae:
  • White or tan color
  • Worm-like body

Pupal Stage

During the pupal stage, the beetle undergoes a transformation known as complete metamorphosis. This process takes roughly 7 to 10 days, after which the adult beetle emerges.

Here is a comparison table of the different life stages of Pleasing Fungus Beetle:

The life cycle of Pleasing Fungus Beetles is fairly quick, allowing them to maintain a stable population within their environment. The common blue Pleasing Fungus Beetle with black spots, for example, thrives in higher, wetter elevations, feeding on various fungi found on decaying logs.

Pleasing Fungus Beetles in Literature and Research

Studies by Entomologists

Researchers have focused on understanding and identifying pleasing fungus beetles. Two key works used for identifying these beetles are a study by Boyle (1956) and another by Dillon and Dillon (1961)¹. The beetles approximately range in size from 2.0 to 22.0 mm¹.

Jeff Mitton’s Observations

Jeff Mitton, an ecologist, made observations on Megalodacne pleasing fungus beetles. These beetles are characterized by their shiny black bodies and yellowish-orange bands on their forewings². They have an elongate oval body shape², and their size varies between ½ to 7/8 inch long².

Features of Pleasing Fungus Beetles:

• Range of 2.0 to 22.0 mm in size¹
• Elongate oval or egg-shaped body¹
• Shiny black bodies with yellowish-orange bands on forewings²

Characteristics of Megalodacne Pleasing Fungus Beetles:

• Elongate oval body shape²
• ½ to 7/8 inch long²

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 – What’s That Beetle from Singapore??? Handsome Fungus Beetle

Subject: Black beetle with 4 yellow dots
Location: Singapore
November 21, 2012 1:18 am
Hi sir,
Please help us. we saw this beetle and we are very curious what species it is
Signature: shirlynn

Dear Shirlynn,
This beetle is very distinctive looking, but we haven’t the time to research it right now as we are preparing to leave the office to spend Thanksgiving with family for several days.  Perhaps in our absence, one of our readers will digest turkey at the computer and they might write in with a comment that identifies the species.

Hi Daniel and shirlynn:
This is a Handsome Fungus Beetle (Endomychidae), not to confused with the Pleasing Fungus Beetles (Erotylidae). Both are large families of beetles that specialize by feeding on fungi or rotting wood. Your beetle is in the genus Eumorphus, but it gets a little tricky after that as there are many to choose from and they are all quite similar. As far as I can determine, at least seven species are native to Singapore and there are probably more. Eumorphus marginatus looks like a pretty close match but I really can’t be certain that that is it. Regards. Karl

Thanks so much for the assistance Karl.  We will need to create a new subcategory for this Handsome Fungus Beetle.

Letter 2 – Aggregation of Fungus Beetle Pupae and Larvae

Cicada?
Location: Mogollon Rim, AZ
July 28, 2011 8:12 am
While camping in Mogollon Rim, AZ in July, we rolled over a log and found these bugs, so the images you’re seeing are upside down. These guys were hardly moving, but there were other slow-moving bugs (the black ones) boring into holes in the log. I’m interested in figuring out what these are and I appreciate your time to help in that effort.
Signature: Jenn

Hi Jenn,
This is a real puzzle for us,  but we believe we know what you encountered.  These look like the Larvae and Pupae of Lady Beetles, commonly called Lady Bugs.  Here is a photo of the Larvae and Pupae of a Twice Stabbed Lady Beetle from BugGuide, and though the match is not exact, we believe you should be able to note the similarities.  We are going to tag this as a mystery because we cannot figure out why such a large number of Larval Lady Beetles would decide to pupate in such a large aggregation under a log.  That does not seem characteristic of what we would expect.  Perhaps we are wrong and they are not Lady Beetle Larvae and Pupae, but we are relatively certain that they are some other group of Beetles.  We will contact Eric Eaton to see if he can provide an answer.  We also want to continue searching to see if there is any documentation of such an occurrence elsewhere on the internet.  Thank you so much for submitting this puzzling identification request.

Eric Eaton makes a correction
August 1, 2011
Daniel:
The beetle pupae are actually of the fungus beetle Gibbifer californicus.
Eric

Letter 3 – Big Fungus Beetle

New Mexico beetle
Hey Bugman,
My friend took a picture of this beetle in the Jemez Mountains of New Mexico last spring. It’s a cute little fella. Any ideas on the species?
Craig Fiehler

Hi Craig,
We needed to go to Eric Eaton for help and he quickly responded: “Yeah, its that Big Fungus Beetle….Cypherotylus californicus. Actually, I think the genus name has changed (using an old, handy guide). Pretty cool. Family is Erotylidae. Eric “

Letter 4 – Exuviae of Fungus Beetle Pupae

Subject:  Whose pupal cases (?)
Geographic location of the bug:  southern Colorado, ponderosa pine forest
Date: 11/26/2017
Time: 06:41 PM EDT
Last spring I cut and split some ponderosa pine firewood in the woods behind my house. Some pieces sat up there all summer, and when I brought them down this fall, I discovered these pupal cases (?) on one chunk. I was curious to know what made them.
(Resending because my images might have been too large last time)
How you want your letter signed:  Chas

Dear Chas,
These are the exuviae or cast off exoskeletons of the pupae of Fungus Beetles, probably Gibbifer californicus.  Here is a similar image from BugGuide.  According to BugGuide:  “Larvae feed on wood-destroying fungi” and “female lays eggs in bark crevices of fallen rotting logs.”

Dear Daniel Marlos,
Fascinating! thanks a lot — now I know where to go for further research.
It was a standing, dead beetle-killed pine, so decay had already started in
some places on the trunk.
Chas S. Cllifton

Letter 5 – Fungus Beetle: Penthe obliquata

Subject: Penthe obliquata–fungus beetle
Location: Mancelona, MI
June 30, 2014 4:26 pm
I found this distinctive black beetle while I was out last night moth hunting, and since he seems to be missing from your archives I’m passing him along! This particular species of polypore fungus beetle is about 1-1.4 cm long (according to Bugguide; consistent with my specimen). That little orange scutellum (right between the thorax and the abdomen) is the key to identifying it, along with the overall rounded shape. Evidently they like living in dry fungus and decomposing trees, both of which we have in abundance around here, though this one was drawn to a lamppost.
Signature: Helen

Dear Helen,
Thank you for your continued efforts to supplement our archives with your excellent images.  BugGuide does have some additional information on this Fungus Beetle that does not have a common name.

Letter 6 – Pleasing Fungus Beetle

Blue beetle
I found this in Flagstaff, AZ, while I was on a hike. It was on an Aspen tree. I’ve never seen a beetle like this before. Can you tell me what it is?
Molly

Hi Molly,
When we first received your letter, we couldn’t immediately identify your Pleasing Fungus Beetle, but we remembered the photo. Today, while researching larvae of the Pleasing Fungus Beetles, family Erotylidae, we stumbled upon photos of the adult Gibbifer californicus on BugGuide, and it matches your submission. So, after three weeks, we have an answer for you and we apologize for the delay.

Letter 7 – Pleasing Fungus Beetle

Variety of burying beetle or…..?
Hi!
I think it’s great that there are so many people out there who are
interested enough in bugs to find out what they are. And I think it’s even better that there is a site where people can go to get help from well-educated and dedicated people such as you. Thanks! Now, on to my bug. I found these in a rotten area of a maple tree in my yard here in northeast Ohio. Looking through your site, I saw many pictures of burying beetles which look quite similar. But these little guys seem to have larger red bands and the head and thorax do not seem so prominent. Any ideas?
-Steven

Hi Steven,
This is a new genus for our site. This is a Pleasing Fungus Beetle in the genus Megalodacne. They are often found in colonies in rotten wood and beneath loose bark. There are two possible species, M. fasciata which grows 9-15 mm and M. heros which is considerably larger, ranging 18-21 mm.

Letter 8 – Pleasing Fungus Beetle

Fungus Beetles
You guys have a great site! I found a dead tree while hiking near Colorado Springs today that had 50-100 of these beetles on it. Many of them were copulating (sorry I didn’t get pics for your insect sex page). I’ve seen them before and wondered what they were. After looking through 6 pages of beetle pics I finally found it. Thanks so much! Further research seems to say that the scientific name has changed to Gibbifer californicus, but it is definitely the right beetle. I’m attaching a picture even though the one you have is probably better.
Heidi

Hi Heidi,
Thank you for taking the time to forward your photo of a Pleasing Fungus Beetle. We think is is quite good.

Letter 9 – Pleasing Fungus Beetle

Wow, doing some research
I have found bugs with the exact shape but nothing simular to the pattern. Seen at the Aiken Canyon Preserve near Colorado Springs. Ever seen one of these? I thought it was a carrion beetle just because the shell looks like it is decaying. Platyphora haroldi. Could it be some sort of flat footed beetle?
Steven Phend

Hi Steven,
This little gem is a Pleasing Fungus Beetle, Gibbifer californicus. According to BugGuide, it is found in “Southwestern United States: Kansas, Wyoming, Colorado, New Mexico, Arizona, south into Mexico.” Additionally: “Adults feed on nectar, pollen, and some fungi. Larvae feed on fungi that are attacking wood.”

Letter 10 – Pleasing Fungus Beetle

Black spots on a blue beetle
Sat, Jun 27, 2009 at 2:00 PM
Hi – We were at Windy Point on Mt Lemmon in Tucson AZ at the end of May and spotted (get it? spotted?) this handsome fellow. I have never seen anything like him before. Can you identify him? I didn’t see his wings.
Julie
Tucson AZ

Hi Julie,
Your beetle is Gibbifer californicus, a Pleasing Fungus Beetle in the family Erotylidae.  The family members are known as Pleasing Fungus Beetles and your specimen does not have a more specific common name.  According to BugGuide, it “Southwestern United States: Kansas, Wyoming, Colorado, New Mexico, Arizona, south into Mexico ” and “Adults feed on nectar, pollen, and some fungi. Larvae feed on fungi that are attacking wood.”

Letter 11 – Pleasing Fungus Beetle

Purple Beetle?
Location:  Bison Ranch, Arizona
September 8, 2010 2:43 am
I came across this beautiful creature in Bison Ranch, Arizona. I’ve been able to find other pictures of it online, but I still can’t find what it is called. Any ideas?
Signature:  Kae

Hi Kae,
Your beetle is one of the Pleasing Fungus Beetles but it has no unique species common name, just the generic family name.  It is Gibbifer californicus and we have not posted a recent image, so your letter is a welcomed addition to our website.  Many individuals of this species are gray or bluish in coloration, so your purple individual is quite striking.  According to BugGuide:  “Adults feed on nectar, pollen, and some fungi. Larvae feed on wood-destroying fungi” and “female lays eggs in bark crevices of fallen rotting logs; adults emerge in summer.”

Letter 12 – Pleasing Fungus Beetle

Subject: What is this bug?
Location: Southbury ct
June 11, 2013 12:07 pm
Dear bugman, I found these cool black & orange bugs this week out back on a fungus. They were 1/2 – 3/4 inches long. The color caught our eye immediately. what is this bug? Also, if you look closely at the picture you can also see small larva / baby bugs in the background. Are the big bugs feasting on the small ones? Could this fungus be their nest? Thanks!!!!!
Signature: Liz

Dear Liz,
This beauty is a Pleasing Fungus Beetle in the family Erotylidae and the genus Megalodacne.  We cannot ascertain if it is Megalodacne heros, which is larger, or Megalodacne fasciata.  According to BugGuide:  “Larvae feed on bracket fungi. Adults overwinter under bark, often in groups.”  The larvae are grubs, and we believe that may be a larva visible in the photo you supplied.

Letter 13 – Pleasing Fungus Beetle

Subject: Beautiful Beetle
Location: Cheyenne cannon, Colorado Springs , Co
June 14, 2016 10:10 am
Hi Mr. BugMan,
I found this wonderfully beautiful beetle out on a nature hike with my children. Let me rephrase we found about 50 of them on a pine log. I would love to know what specimen it is and if it is native to Colorado .
Signature: Stephanie Clements

Dear Stephanie,
This Pleasing Fungus Beetle was likely emerging from the log after feeding  on fungus growing on the pine log as larvae.  According to The Firefly Forest:  “Pleasing Fungus Beetles (Gibbifer californicus) are blue, fungus-loving beetles found in parts of Wyoming, Colorado, Kansas, New Mexico, Arizona, and Mexico. Here in Arizona, they are fairly common in moist riparian woodlands with large trees. Adult Pleasing Fungus Beetles emerge in the summertime and are most numerous during the summer monsoon rains.”  According to BugGuide:  “Adults feed on nectar, pollen, and some fungi. Larvae feed on wood-destroying fungi.”

Letter 14 – Pleasing Fungus Beetle

Subject: Cockroach or beetle?
Location: Columbus, OH
July 21, 2016 4:19 am
Found this guy stuck on its back in my kitchen. I live in an old home (1920) in an urban neighborhood. I helped him out and got him on his feet but would like to know what exactly I helped. Is it a cockroach or a beetle?
Signature: Apprehensive helper

Dear Apprehensive helper,
This is a Pleasing Fungus Beetle in the genus Megalodacne which we identified on BugGuide where it states:  “Larvae feed on bracket fungi. Adults overwinter under bark, often in groups.”  Perhaps there is a large tree with mushrooms growing on it near your kitchen and this individual accidentally found its way indoors.

Letter 15 – Pleasing Fungus Beetle

Subject:  Bugs on fungus on maple tree
Geographic location of the bug:  Southern Indiana
Date: 09/20/2017
Time: 01:01 PM EDT
I believe these to be some sort of blister beetles. All I have been able to find are blister beetles with 3+ colored bands. I have never seen them before, but cannot find information about them being in our area. Your help is appreciated.
How you want your letter signed:  Thanks! Sasha

Dear Sasha,
This is a Pleasing Fungus Beetle in the genus Megalodacne.  Based on the BugGuide information that “Note also different form of scutellar macula, and pronotal sides near hind angles (slightly concave in heros / straight to slightly convex in fasciata)” we are leaning toward this being Megalodacne fasciata.

Letter 16 – Pleasing Fungus Beetle

Subject:  Bug in smoky mountain national park near Gatlinburg
Geographic location of the bug:  Above
Date: 04/29/2019
Time: 05:54 PM EDT
Your letter to the bugman:  Curious as to what this bug is?
How you want your letter signed:  Dawn

Dear Dawn,
This is definitely a Pleasing Fungus Beetle in the genus Megalodacne, and according to BugGuide:  “Larvae feed on bracket fungi. Adults overwinter under bark, often in groups.”  We are puzzled as to what is protruding from its abdomen.  No images on BugGuide depict such an ovipositor.  We have contacted Eric Eaton for his opinion on this.

Eric Eaton Confirms:
Your assessment is correct.  Many beetles, especially those that place eggs in bark crevices or other nooks and crannies have telescoping ovipositors like this.
Eric

Letter 17 – Pleasing Fungus Beetle

Subject:  What is this bug?
Geographic location of the bug:  under rotting old maple tree in RI
Date: 05/04/2019
Time: 05:42 PM EDT
Your letter to the bugman:  same as above
How you want your letter signed :  anyway

Dear anyway,
This is a Pleasing Fungus Beetle.

Letter 18 – Pleasing Fungus Beetle AKA Humpty Dumpty Erotylidae

Bug question for the Bugman
Hello Bugman,
What an amazing and beautiful website! I wish I stumbled across it sooner. It is a great inspiration; it makes me want to learn more about these awesome creatures. Thank you. We found this beetle crawling on a rock near a mountain stream in Colorado. It was sometime around October, 2005. Any ideas? I tried looking it up but had no luck.
alicia

Hi Alicia
We decided to check in on Eric Eaton for help and he quickly responded: ” It’s a pleasing fungus beetle, Gibbifer californicus, in the family Erotylidae. This is one of the larger, more spectacular species, found in the southwest U.S.” The adults and larvae both feed on a variety of wood rotting fungi, hence the name Pleasing Fungus Beetle. Additional research turned up this amusing name: Humpty Dumpty Erotylidae.

Letter 19 – Pleasing Fungus Beetle from Brazil

Subject:  ID please
Geographic location of the bug:  SE Brazil
Date: 11/27/2017
Time: 06:45 AM EDT
Please can you ID the three insects on the enclosed enclosed photos please
How you want your letter signed:  GP

Dear GP,
The yellow and black beetle is a Pleasing Fungus Beetle in the family Erotylidae, and we found a matching image on FlickR, but alas, it is only identified to the family level.  In the future, please limit your identification requests to a single species per submission.  We will be postdating your submission to go live to our site later in the month while our editorial staff is away for the holidays.

Letter 20 – Pleasing Fungus Beetle from Colombia

Subject: Gibbifer gibbosus?
Location: La Estrella, Antioquia, Colombia
December 17, 2014 9:39 am
I found this beautiful beetle walking over a fungus, near Medellin, Colombia, at about 1700 m over the sea level. So I think it could be a “pleasing fungus beetle”, but I only find references of this species in Central American countries.
During my search in internet, I also found the latin word “gibbosus” that means “humpback”. It seems to be clearly the case of this beetle.
Signature: luchogu

Dear luchogu,
Your images of a Pleasing Fungus Beetle on its namesake food are spectacular, but they took us so long to format for the web that we don’t have the after final energy to research their identity, but we believe the genus Gibbifer is correct.
It’s a new day and we are linking to a Costa Rican Pleasing Fungus Beetle submission from earlier in the year that might be Gibbifer gibbosus, but we were never able to substantiate that identification.  Insetologia from Brazil has an image of a Pleasing Fungus Beetle that look identical to your individual that is identified as being in the genus Cypherotylus, a name we cited as obsolete in a posting from our archives.  FlickR includes an image of a Pleasing Fungus Beetle in the genus Gibbifer, but it looks nothing like your individual.  A search for Gibbifer led us to another FlickR image from Peru that looks similar to your individual, but it is only identified to the genus level.

Letter 21 – Pleasing Fungus Beetle from Costa Rica

Subject: Pleasing Fungus Beetle (Gibbifer sp.)
Location: Rincon de la Vieja NP, Costa Rica
May 10, 2014 5:48 pm
I found this beetle while hiking in the Rincon de la Vieja National Park in Costa Rica. I’m guessing that it belongs to the genus Gibbifer based on the ID that I found here on your pages. But I couldn’t find any matches for a species ID. Maybe you or some of your readers can help.
Signature: Siggy

Hi Siggy,
You are correct that we have several examples from Costa Rica of Pleasing Fungus Beetles in the genus Gibbifer, but we cannot substantiate their species identity.  There is a posting on Project Noah that is identified as Gibbifer costaricensis.  That same species is represented on Biologia Centrali Americana, however, the obsolete genus name Cypherotylus is used.  It is also important to understand that insects do not respect international boundaries drawn up by humans.

Daniel,
Thanks for replying so quickly. I seen that plate from Biologia Centrali Americana as well and thought insect #3 matched mine pretty closely. But when I did a search on Gibbifer gibbosus, what I assume would be the current name, I found pictures of beetles without the black band across the middle. I don’t know how much variability can be expected in a species, but maybe it’s just a variant.
I have a few more pictures of some insects that I want to ID from that hike. If I can’t come up with anything myself I may resort to enlisting your help again. Even if I can ID them, I’ll submit the images for use on your site.
Siggy

Hi again Siggy,
We would love to see any identified images from your hike.  It is much easier for us to post interesting images of interesting creatures without having to do any additional research.  Please include the species name and location in the subject line to catch our attention as traffic is once again increasing due to warming weather in much of the northern hemisphere.

Letter 22 – Pleasing Fungus Beetle found in suitcase

Subject:  should I throw my luggage away?
Geographic location of the bug:  Chattanooga, TN
Date: 11/04/2017
Time: 09:48 AM EDT
I found this in my dirty clothes, after I got back from a local overnight convention. I didn’t put any reference in the pictures for lengthy, but it’s about a centimeter long and maybe half that, wide.
How you want your letter signed:  Buggy, in ChattaBoogie

Dear Buggy,
This appears to be a Pleasing Fungus Beetle, and we suspect it accidentally entered your suitcase.  It is harmless and will not infest your home, nor will it damage your house or its furnishings.  You do not need to throw your luggage away.

Thank you! Y’all do great work!! Thanks for setting my mind at ease. Happy Holidays!
Buggy in ChattaBoogie

Letter 23 – Pleasing Fungus Beetle from Costa Rica

Costa Rican Fungus Beetle?
Is this a fungus beetle? It looks a lot like Gibbifer californicus, but lacks the patch of black in the middle of the abdomen that I’ve seen in every photo of the Pleasing Fungus Beetle. This beetle also seems to have a lighter blue color and has a black patch on the posteriormost tip. Could it be a relative? It was found at about 1000m elevation on the Pedregal Hill of the Cacao Volcano within the Área de Conservación Guanacaste, northwestern Costa Rica.
Scully

Hi Scully
According to BugGuide, Gibbifer californicus, one of the Pleasing Fungus Beetles, ranges into Mexico. Chances are good that it ignores the international borders and can be found in Costa Rica as well. If this is not the same species, it is at least the correct genus. There are often individual variations between the coloration of individuals and even more so in isolated populations.

Letter 24 – Pleasing Fungus Beetle from Costa Rica

costa rican beetle
March 28, 2010
This beetle was in the InBioParque in San Jose, Costa Rica last summer. It crawled to the sunny ends of branches and twigs. I only saw it by itself. Do you know what kind of beetle this is?
Thanks!
Jenny
costa Rica, San Jose, InBioParque

Hi again Jenny,
This is our final response for the night.  This is a Pleasing Fungus Beetle.  It bears a striking resemblance to Gibbifer californicus, the only species in the genus found in the U.S. according to BugGuide.  We posted a member of the genus from Costa Rica in 2007.  We searched for internet coverage of the genus from Costa Rica, and found a photo of a specimen on the La Anita Rainforest Ranch website that seems to look very similar to your individual, though we believe it is incorrectly identified as Gibbifer californicus.

Letter 25 – Pleasing Fungus Beetle from Panama

Leaf Beetle from Panama
Bugman,
Since I’ve sent you two unknown spiders and a caterpillar from Panama, I thought I’d send you one that I believe I have identified. I believe this is Platyphora boucardi, in the family Chrysomelidae, and has been featured on a Panamanian stamp.
Allen Chartier
http://www.amazilia.net/

Hi Allen,
Though the color and markings are similar, the legs and clubbed antennae of your beetle are different from the Platyphora boucardi images we located online. We aren’t even convinced your beetle is in the same family. It might be a Pleasing Fungus Beetle in the family Erotylidae. Perhaps one of our readers can supply additional information.

Daniel:
You are absolutely correct: the beetle is one of the pleasing fungus beetles in the family Erotylidae. Great job, I always get those two families of fungus beetles confused:-)
Eric

Letter 26 – Pleasing Fungus Beetles, in California!!!

Subject: Strange bug nest
Location: Modesto, California
August 13, 2012 8:39 pm
Hello! I was outside walking my dog and saw what I thought was throw up. I took a closer look and realized it was not throw up, but a strange nest. When poked with a stick, the stick broke due to how tough this stuff was. When poked with a more DURABLE stick, a white liquid came out (but the stick eventually snapped). What might this all be? What type of bugs?
Signature: Kate

Hi Kate,
This is a most curious submission, and we are going to get a second opinion from Eric Eaton.  This is not a nest.  It is a fungus and the beetles are Pleasing Fungus Beetles.  The curious thing is your location in Modesto, California.  We are nearly certain that these Pleasing Fungus Beetles are in the genus Megalodacne as evidenced by the photos posted to BugGuide, however, Bugguide states:  “Two Nearctic species” are found in “Eastern United States and Canada.”  BugGuidereports them as far west as Texas.  We can’t help but wonder which of the following possibilities is the solution.  Perhaps there is an undiscovered west coast species, or perhaps the range of one of the two eastern species is much greater than originally supposed, or perhaps they were somehow introduced, either accidentally or naturally through range expansion.  Further research led us to the FSCA Coleoptera site that states:  “There are two species of this genus occurring in the eastern United States, and a record of a potenitally [sic] establishment in California.”  We will contact Paul E. Skelley who is posted that statement with your sighting.  HGTV states:  “Megalodacne fasciata, which is smaller and has slightly different markings on its back, has been seen throughout most of the East and Midwest, plus California.”

Paul Skelley Responds
Daniel,
Megalodacne fasciata was first reported in California by Kitayama (See Attachment:  Kitayama 1986-New Distribution for Megalodacne fasciata). Since my page on the web was posted long ago, I have seen several other specimens from several other Californian localities. Megalodacne fasciata appears to be established. Megalodacne species prefer bracket fungi that are “soft” when fresh and growing, but which turn very hard as they mature. Your reader’s photo appears to be a Ganodera sp., bracket fungus, but I am not familiar with the western species.
Paul

Eric Eaton Responds
Daniel:
Yes, Art Evans features Megalodacne fasciata in his Field Guide to Beetles of California.  He says they are most active at night, so a daytime image would be something somewhat unusual.
Eric

Letter 27 – Pleasing Fungus Beetle Larvae

Subject: larvae
Location: NE Pennsylvania, near Philadelphia
November 20, 2016 11:17 am
Dear Bugman,
Can you help me identify these larvae? I found them under a decaying mushroom. The mushroom looked similar to a reishi mushroom. I found them on September 21, ’16,not far from my vegetable garden. The mushrooms were growing around the roots of a decaying maple tree trunk. There were other mushrooms just like this. Good bug, or not so for my garden? I left them for the birds to eat, also they were really cool looking.
Thanks for any help with this.
Signature: Best, Marie Cooney

Dear Marie,
Because you found them in association with a “decaying mushroom,” we took the chance that these might be Pleasing Fungus Beetle larvae, and our hunch proved correct based on this BugGuide image of Megalodacne fasciata.  According to BugGuide:  “Larvae feed on bracket fungi. Adults overwinter under bark, often in groups.”  In our opinion, this is a benign or beneficial species in the garden.

YAY! Thank you so much for identifying, it was driving me crazy!
Best,
Marie

Letter 28 – Pleasing Fungus Beetle from Peru

Subject: Beetle from the Madre de Dios region of Peru
Location: Los Amigos Biological Station (CICRA), Madre de Dios, Peru
June 14, 2017 7:17 am
Hello!
Recently, I went to the Peruvian Amazon and saw some pretty amazing insect life! However, I’m having a really tough time identifying most of them, although I’ve gotten a couple out of sheer luck. I was wondering if you could help me with this one, if not a couple more afterward! Most of them aren’t great pictures or anything, but any help would be wonderful!
Signature: Sincerely, Noah

Dear Noah,
We thought this resembled a Pleasing Fungus Beetle in the family Erotylidae, and we quickly found this image on FlickR that is identified as Scaphidomorphus bosci.  The species is also pictured on Encyclopedia of Life and iNaturalist.

Letter 29 – Pleasing Fungus Beetles

whats my bug
Hello, I found these beauties while hiking in Western Pennsylvania. There were a dozen or so of these beetles enjoying the delicious fungus in the picture. Curiosity got the best of me and I snapped a few pictures. Thanks,
Brian

Hi Brian,
They are pleasingly attractive beetles, and they eat fungus. Someone thought to name them Pleasing Fungus Beetles, Megalodacne heros. Here is a nice side by side comparison with a smaller relative, Hegalodacne fasciata.

Letter 30 – Pleasing Fungus Beetles

Dear Bugman,
First of all, i think this is the single most fascinating website I have ever seen. Whenever I visit, I sit and read for hours (much longer than i should). Anyway, last spring my red maple failed to produce a single bud or leaf (I supposed it had died during the winter). No explanation of this tragedy presented itself. This afternoon, however, I was looking around for some foliage for my pets, when I saw that the bark was starting to fall off of the red maple’s trunk. Being extremely curious, I pulled some bark from the tree and found these beetles overwintering underneath. Could you identify them for me? And could they be responsible for my young tree’s demise? Thank you so much,
Annie Baker, Maryland

Hi Annie,
Thank you so much for your very kind letter. Your beetles are Pleasing Fungus Beetles, probably in the genus Megalodacne. We believe they are Megalodacne fasciata though it is difficult to be certain in a photo. According to our Field Guide to the Insects of America North of Mexico by Borror and White: Pleasing Fungus Beetles “are usually found on fungi or in rotten wood; some are fairly common. Adults hibernate under bark, often in groups.” The beetles are not responsible for the demise of your tree, but they are feeding on the fungus that is assisting in its decomposition.

Letter 31 – Pleasing Fungus Beetles

Subject: Id help
Location: Maryland
August 22, 2013 11:39 am
Hi,
Was out walking and thought these bugs were beautiful and have no idea what they are or what they are doing. Are they attacking a tree or feasting on a fungus? Would love help getting them identified. I’ve only seen them once in the forest.
Thanks you!
Signature: Nature lover

Dear Nature Lover,
These are Pleasing Fungus Beetles in the genus Megalodacne.  They are feeding on fungus as their name implies.

Letter 32 – Pleasing Fungus Beetles

Subject: Bugs
Location: Indiana
April 11, 2015 3:54 pm
These bugs are on a hackberry tree.
Signature: Mag

Dear Mag,
These are Pleasing Fungus Beetles in the genus Megalodacne and they will not harm your tree.  According to Featured Creatures:  “In the United States, the pleasing fungus beetles are not economically important, but in the Orient where many people regularly collect and eat wild mushrooms, pleasing fungus beetles may be considered pests (Boyle 1956). Many of the fungi upon which these beetles feed are edible by humans. Currently none of these fungi is easily cultivated and they are not sought after by most people. With the increasing popularity of mushrooms and cultural technological advances, it is possible that pleasing fungus beetles may become economically important in the United States. If these beetles become pests, chemical control is not recommended because mushrooms are very absorbent. Biological or cultural controls should be considered.  These beetles may also be beneficial. Fungi like Inonotus spp. and Armillariella spp. are known to be pathogenic to hardwood trees. These fungi also serve as hosts for several species of pleasing fungus beetles.”

Letter 33 – Pleasing Fungus Beetles in California

Subject: Oak Tree Beetle
Location: Foothills east of Sacramento, Ca
August 1, 2016 7:11 am
I live in Northern California in the Sierra foothills. We recently had a large, established oak tree die. I noticed a couple nodes at the base that I was able to break off. I found an infestation of black and orange beetles. Trying to figure what they are, if they killed the tree or if they just move in after the tree is dead/dying. And what to do to make sure they don’t spread to our other trees.
Signature: Thank you, Ian

Dear Ian,
These are Pleasing Fungus Beetles, probably Megalodacne fasciata, and they are not responsible for the death of your oak tree, however, their presence is tied to the health of the tree.  According to BugGuide:  “larvae and adults feed on the fruiting bodies of fungi growing in decaying wood.”  So, as the tree began to die, it was invaded by the fungus and the fungus attracted the Pleasing Fungus Beetles.

Letter 34 – Pleasing Fungus Beetles, we believe

Bug on Mushroom on down Oak Tree
Location: Memphis, TN
June 5, 2011 2:46 pm
Mr. Bugman,
These little critters are all over a downed oak tree in my yard. As you can see, the white part is mushrooms growing on the tree. The bugs are primarily on the mushrooms, but are on other part of the tree as well.
Signature: David Gordon

Hi David,
We believe these are Pleasing Fungus Beetles in the family Erotylidae (see BugGuide), but we cannot make out enough detail in your image to be certain.  They most resemble the BugGuide images of Ischyrus quadripunctatus, but we cannot make out the identifying four spots in your photo.

Daniel,
Thank you so much. I didn’t really need a genus, I just really needed to make sure they weren’t “harmful” like ticks or something I needed to make an effort to get rid of them.  If they are beetles, from what I understand, they are beneficial and I will leave them to live their lives in peace.
Thank you again,
David

Letter 35 – Polyphore Fungus Beetle

Subject: Classy black beetle with orange dot. Not a lady bug.
Location: Troy, VA
July 30, 2016 12:45 pm
I saw this beetle last night and I think he is terribly elegant. I’m very curious as to what it is, I can’t find beetles like it with one orange dot. He does, alas, seem to be missing at least one leg.
thank you
Signature: Grace Pedalino

Dear Grace,
This is a Polyphore Fungus Beetle in the family Tetratomidae, Penthe obliquata, and we identified it in Arthur E. Evans wonderful book “Beetles of Eastern North America”.

Letter 36 – Possibly Pleasing Fungus Beetle from Vietnam

Subject: Beetle ID – Black with green patches
Location: Cuc Phuong National Park, Vietnam
April 9, 2016 12:12 am
Hi there,
I enjoy your site, and it has been a great help to ID some of the local bugs I find in California. Recently I went to Vietnam and this bug caught my attention. I have tried to do my due diligence identifying it myself but I’m not getting anywhere. It was seen March 8th at approximately 8 p.m. For size reference, I think about 3/4″? Any help would be appreciated.
Thank you!
Signature: Alison

Dear Alison,
Based on the shape of the antennae and other features, we believe this is a Pleasing Fungus Beetle in the family Erotylidae, but we have not had any success finding any matching images online with this striking black and green coloration.  The closest we would find is this image on Alex Hyde Photography of an unidentified Malaysian species with similar, though yellow markings.  There are examples of beetles, like the Australian Fiddler Beetle, that have green coloration while other members of the same species are yellow.  There is another similar looking Pleasing Fungus Beetle on the Beetles of Borneo site.  Perhaps one of our readers will have better luck than we have had. 

Letter 37 – Red-banded Fungus Beetle and probable Larvae

Coolest Fungus Beetle on EARTH!
Bugman,
I have attached two photos taken at Skidaway Island State Park in GA during the month of August this year. One is of a fungus beetle that I think is Megalodacne fasciata. I observed that beetle (and many of its friends) on one of my favorite mushrooms, Ganoderma lucidum. A couple weeks later, that same patch of mushrooms in the same location had these cool looking larvae infesting them. I have not been able to verify that these larvae are those of Megalodacne fasciata, I just assume. I have seen horned fungus beetles on these same mushrooms. I checked bugguide for larval images with no luck. What do you think? Are these Megalodacne fasciata larvae? You guys rock!
Anthony

Hi Anthony,
Thanks for sending your awesome photos of a Red-Banded Fungus Beetle, Megalodacne fasciata, and potentially the larvae of the same species. We located a nice site with good information, but we did not have any luck locating images of the larvae online. We will contact Eric Eaton to get his opinion, but our gut feeling is that we are inclined to agree with your speculation based on compelling circumstantial evidence.

Update: (08/26/2008)
Hi Daniel:
I would tend to agree with the conclusion reached re: the fungus beetle and larvae. Nice work by the person who discovered this.
Eric Eaton

Letter 38 – Pleasing Fungus Beetle

Possible Sexton / Burying Beetle
Hi,
While mushroom hunting in the woods the other day, I came across an Artist’s Conk or Artist’s Fungus (which they are often called), and upon closer examination, I noticed this beautiful beetle walking across it. I’m glad I always carry my camera as you never know what interesting things you’ll come across ~ example mentioned. Anyhow, I did a little research and believe this to be a Sexton / Burying Beetle . . . am I correct? Photos taken by me ~ 9-1-2007 (Northeast Ohio) Thanks,
T. Theiss

Hi T,
We are actually very happy your identification is incorrect. The markings on your Sap Feeding Beetle resemble those of a Burying Beetle, but the two are not closely related. Your Sap Feeding Beetle, Glischrochilus fasciatus, is in the family Nitidulidae. The reason we are excited is that your photo represents a new family, genus and species for our site. Thanks for your contribution.

Correction:  July 7, 2013
Pleasing Fungus Beetle
Today while trying to identify another red and black beetle, we realized that this old posting had been misidentified.  This is actually a Pleasing Fungus Beetle in the genus Megalodacne.  See BugGuide for additional information.

Letter 39 – Two Pleasing Fungus Beetles from Bolivia

Subject: What’s This Coleopteran?
Location: Chalalán Ecolodge, Madidi National Park, Aten Canton, Apolo Municipality, Franz Tamayo Province, La Paz Department, Bolivia
January 25, 2017 4:03 pm
These are two different individuals that I believe to be from the same family, if not genus. If possible, I would love to know what family that is. One is purple and black, and the other is white and black, and their elytra come to an arch or point in the center of their body. These were found and taken at Chalalán Ecolodge, Madidi National Park, Aten Canton, Apolo Municipality, Franz Tamayo Province, La Paz Department, Bolivia. This is a NT0166 Southwest Amazon Moist Forest WWF Ecoregion.
Signature: Thank you so much WTB

Your purple beetle is a Pleasing Fungus Beetle in the family Erotylidae, and this individual from Columbia in our archives shares characteristics with your individuals, so we are in agreement that both beetles are in the same family.  This image on Getty Images is only identified to the family level.  We located this cyan-blue individual on Project Noah that is identified as Cypherotylus cf. dromedarius, with the species name being a reference to the camel-like hump.  Insetologia, our sister site in Brazil has this wonderful posting. 

Letter 40 – Probably Pleasing Fungus Beetle Exuviae on Douglas Fir in Colorado

Subject: Help Identify
Location: Colorado
April 28, 2016 1:56 pm
found these on a few mature Douglas fir.
Signature: John

Dear John,
These are the exuviae or shed exoskeletons of some unknown insect.  We will continue to research their identity.

Update May 4, 2016:  Introducing our new intern Bennett
Several weeks ago, we received an intriguing request from a local neighbor that eventually led to a meeting with our neighbor and his young science-minded son.  In his free time, Bennet will be attempting to identify the currently 444 unidentified postings in our archives.

Subject: Need Help?
Location: Los Angeles
April 27, 2016 9:33 pm
Hi Daniel,
I am a neighbor on Mt. Washington (Ave 37) and I have a science minded teenager. He’s done experiments at the Cabrillo Aquarium, won multiple medals in the LAUSD science bowl since grade 5 and was Captain of the Eagle Rock Science Olympiad team that went to the national finals in 2013. I was wondering if you ever need help or took on an intern (non-paid of course) for WtB? He wants to study entomology and I thought perhaps a project like yours would be a fun spot for him.
Thanks,
Todd

Here is Bennett’s first attempt at identifying a recent posting.

May 3, 2016
Hi Daniel, this is Bennett. I’m sorry for not looking into the unidentified post earlier, I had a lot of schoolwork getting in the way. Now that I spent some time looking at it and doing some research it seems to resemble some sort of carpet beetle larvae shedding. I’m not able to give a definite ID on species, and I could be wrong on this, but after doing some research it’s my best guess so far. I’ve attached 2 images that seem similar to the images the person provided, but the main difference is the lack of spikes at the tip of the tail. I hope this helps in some way.

Thanks so much for looking into this unidentified posting Bennet.  Our big doubt regarding Carpet Beetle exuviae is that the habitat seems wrong.  The exuviae are hanging from the tip of the abdomen, which is a common orientation for Lepidoptera pupae as well as Coleoptera pupae.  Our initial thought is that this was most likely one of those two orders.  We do have one request in the future:  Please provide links to images you locate in your online research rather than to attach the images.  We cannot pilfer images from another site to post them to WTB? as that would be plagiarism.  A better strategy is to link either to an outside site or even better, to link to our own archives.  We are not yet closing the book on this ID.  Searching for caterpillars or beetle larvae that feed in large numbers on Douglas Fir would be a good start.  We would also not entirely rule out that these might be Sawfly exuviae.  We believe they are pupal casings and not larval casings, indicating that the insect that left them has complete metamorphosis.

Update from Bennett:  May 23, 2016
Hi Daniel,
… I do think that I have positively identified the mystery exuviae. The images seem also identical to the exuviae of the Fungus Beetle (Gibbifer californicus), I am almost positive that it is this or another closely related species. Here is the bugguide page that contains the image that I found identical: http://bugguide.net/node/view/253897/bgimage
I hope this is accurate!

Wow Bennett,
That BugGuide posting looks like a really good visual match.  Additionally, according to BugGuide, the species is found in Colorado.  BugGuide also states “Larvae feed on wood-destroying fungi” and “female lays eggs in bark crevices of fallen rotting logs” and though the exuviae are on a branch attached to a tree, it is also possible that it could be a lower, dead branch that has fungal growth.  Of the family Erotylidae, the Pleasing Fungus Beetles, BugGuide notes:  “larvae and adults feed on the fruiting bodies of fungi growing in decaying wood” and fungus is frequently found on living trees that are compromised.  We agree that though this might not be the exact species, it is likely something closely related.  Great job Bennett.  Thanks so much for helping us to clear up some postings that are currently Unidentified on our site one posting at a time.