Carrion beetles are fascinating insects known for their unique ecological role in consuming dead and decaying animals.
These beetles, belonging to the family Silphidae, play an essential part in recycling nutrients and speeding up the decomposition process in nature.
There are a variety of carrion beetles, with the American burying beetle (Nicrophorus americanus) being the largest in North America.
American Carrion Beetle
This species reaches 1.0 to 1.8 inches in length and displays a distinctive orange-red on shiny black coloration.
Another common species is the American carrion beetle (Necrophila americana), known for its yellow pronotum with a black spot in the middle, and an adult length of about ½ to ¾ inch.
Carrion beetles serve as nature’s “clean-up crew” by consuming the remains of deceased animals. Additionally, they can help control the population of other insects, such as fly maggots, which also thrive on decomposing organisms.
Overall, carrion beetles hold a significant place in the ecosystem and should be appreciated for their important role.
Carrion Beetle Overview
Carrion beetles belong to the family Silphidae and are known for their unique behavior of feeding on decaying organic matter, such as dead animals.
Notable examples of this family include the American burying beetle (Nicrophorus americanus) and the European carrion beetle.
Sizes vary between various species of carrion beetles.
The American carrion beetle (Necrophila americana) and the American burying beetle (Nicrophorus americanus) are both part of the Silphidae family.
The American burying beetle is the larger of the two, ranging from 1.0 to 1.8 inches (25 to 35 centimeters) in length1.
Meanwhile, the American carrion beetle is smaller, with adults between ½ to ¾ inches in length2.
Both types of beetles are predominantly black, with contrasting features.
The American burying beetle often has red, orange, or yellow markings, while the American carrion beetle has a distinct yellow pronotum (the plate-like structure that covers the thorax) with a large, central black spot2.
American Carrion Beetle
Carrion beetles are generally flattened, with the American carrion beetle resembling a bumblebee while in flight2.
The shell-like forewings (elytra) in both beetles have a distinct pattern, narrower toward the front and wider toward the end of the body3.
The antennae of carrion beetles are often clubbed, with several segments at the end forming a distinctive ball-like structure.
This feature allows them to better detect odors associated with carrion, helping with their scavenging lifestyle.
As mentioned earlier, the elytra in carrion beetles are wider toward the end of the body and narrower toward the front3.
In many species, their elytra are too short to cover the entire abdomen, leaving the hind wings exposed.
A key feature to differentiate between American burying and carrion beetles is the pronotum.
The American burying beetle usually has a black pronotum, while the American carrion beetle has a yellow one with a large, black central spot2.
Comparison Table: American Burying Beetle vs American Carrion Beetle
|Feature||American Burying Beetle||American Carrion Beetle|
|Size||1.0 to 1.8 inches||½ to ¾ inches|
|Color||Black with red, orange, or yellow markings||Black with yellow pronotum and black spot|
|Shape||Flattened body||Flattened body, resembles bumblebee in flight|
|Antennae||Clubbed at the end||Clubbed at the end|
|Elytra||Shell-like, wider at the end||Shell-like, wider at the end|
|Pronotum||Black||Yellow with black central spot|
Distribution and Habitat
Carrion beetles are distributed across various continents and can be found in diverse habitats where decaying organic matter is present.
For instance, the American burying beetle was once widespread across North America, but its populations have declined, and it is now listed as endangered in the U.S.
European carrion beetles are native to Europe but have also been found in North America over time.
Biology and Behavior
Carrion beetles go through a complete metamorphosis consisting of four stages: egg, larva, pupa, and adult.
Female beetles typically lay their eggs near a suitable food source, such as a carcass or rotting fruit.
The larvae hatch from the eggs and begin feeding on the food source alongside any competing maggots present.
The carrion beetle larvae are teardrop-shaped, black grubs that somewhat resemble sowbugs1.
After consuming enough food, the larvae fall to the ground and burrow into the soil where they pupate2.
The adult carrion beetles emerge from the pupae and continue to forage for food, contributing to the ecosystem as scavengers.
Carrion Beetle Larva
Diet and Carrion Utilization
Adult carrion beetles primarily feed on:
- Carcasses of small animals ( e.g., rodents, birds)
- Insects (especially fly maggots)
- Rotting fruit and vegetation
They play a crucial role in the ecosystem by helping to recycle nutrients and decompose animal carcasses3.
In addition to their diet, some carrion beetle species aid in burying carcasses, such as the American burying beetle, which can measure up to 1.8 inches in length.
Here’s a comparison table of two well-known carrion beetle species:
|Species||Size||Coloration||Diet and Behavior|
|American Burying Beetle||1.0 to 1.8 in||Black and orange markings||Buries carcasses/subterranean; feeds on fly larvae, carrion|
|American Carrion Beetle||0.5 to 0.75 in||Yellow and black markings||Dwells under large carcasses; feeds on fly maggots, carrion1|
Carrion beetles are primarily nocturnal creatures. They scavenge for food in the evening, guided by the sense of smell from their antennae.
They prefer to remain in damp, dark habitats like forests, using their strong sense of smell to locate food sources4.
To summarize, here are some notable nocturnal habits of carrion beetles:
- Attracted to lights, which can sometimes lead them into human habitats
- Rely on olfactory cues from decomposing matter and carcasses
- More active during warmer months, when food sources are more abundant
Carrion beetles are capable of flight. These beetles are equipped with two pairs of wings, like most other beetles.
The front pair, known as elytra, are hard and protective, covering the more delicate hind wings which are used for flying.
The elytra open up to allow the hind wings to unfold when the beetle decides to take flight.
Carrion Beetle Wings
Carrion beetles utilize their flying ability to move between different locations in search of food sources, primarily decaying animal matter.
Flying enables them to cover greater distances and find suitable environments for laying their eggs and continuing their life cycle.
While they are not renowned for their flying skills compared to other insects, their ability to fly plays a crucial role in their survival and ecological contributions.
Carrion beetles have various predators, including birds, mammals, and other insect-eating creatures.
Carrion beetles are active across different seasons, and their presence varies depending on habitat, abiotic factors, and geographic location.
Interaction with Ecosystem
Decomposers and Ecological Role
Carrion beetles play a vital role in ecosystems as decomposers.
They break down dead animals, returning nutrients to the soil. Some key carrion beetles include:
These beetles also help control insect populations because their larvae feed on maggots of flies that compete with beetle larvae.
Interactions with Other Species
Mutualistic Relationship with Mites
Carrion beetles share a fascinating mutualistic relationship with mites.
Mites hitch a ride on the beetles to new food sources, such as decaying carcasses, where they:
- help the beetle by consuming fly eggs
- benefit themselves by gaining access to food
This relationship helps both species to thrive and reduces competition for resources.
Competition with Flies
Carrion beetles face competition from other decomposers, primarily flies.
Both beetle larvae and fly larvae rely on the same decaying organic matter for nourishment. However, carrion beetles have a few advantages:
- ability to feed on fly eggs, reducing fly population
- removal of unwanted by-products from decomposition
Role in Forensic Entomology
Carrion beetles have a significant role in forensic entomology, the study of insects in criminal investigations.
As beetles arrive at different stages of decomposition, they can provide valuable information.
For example, determining the time since death, or post-mortem interval (PMI).
|Species||Role in Forensic Entomology|
|Carrion Beetles||Help determine time since death by analyzing their arrival at the scene|
|Nicrophorus||Aid in locating buried remains, as they are attracted to deeper carcasses|
In conclusion, carrion beetles have complex interactions with mites, flies, and play an important role in forensic entomology.
Understanding these relationships helps us appreciate their role in the ecosystem and their application in criminal investigations.
In some cases, these beetles also participate in plant pollination.
The Liceoptoma carrion beetles have been observed pollinating yucca plants2, which evolved a special mechanism to attract the beetles.
The yucca flowers emit a scent that mimics the smell of rotting flesh, attracting beetles that crawl into the flowers, inadvertently pollinating them.
To summarize, carrion beetles perform some very important roles in the ecosystem
- Decompose dead animals, recycling nutrients
- Control insect populations, reducing competition for resources
- Can be pollinators for some plant species
Pustulated Carrion Beetle
Types and Variation
Burying beetles, also known as Nicrophorus, are a prominent group of carrion beetles. They are characterized by:
- A distinct color pattern: black with red, orange, or yellow markings
- Unique elytra: wider towards the end, narrower towards the front
Some notable species include:
- American burying beetle (Nicrophorus americanus)
- Nicrophorus vespilloides
- Nicrophorus humator
- Nicrophorus investigator
Burying Beetle with Phoretic Mites
Sexton beetles belong to the genus Nicrophorus and are similar to burying beetles. They can be identified through their:
- Antennae: with a club-like structure at the tips
- Abdomen: exposed 1 to 3 segments due to short elytra
An example of a sexton beetle species is Nicrophorus vespilloides.
Red-Breasted Carrion Beetle
The red-breasted carrion beetle, scientifically known as Oiceoptoma thoracicum, has unique features:
- A red thorax: distinguishing it from other carrion beetles
- Fondness for fungi: unlike burying and sexton beetles
|Feature||Burying Beetles||Sexton Beetles||Red-Breasted Carrion Beetle|
|Color||Black, red, orange, yellow markings||Similar to burying beetles||Black with red thorax|
|Elytra||Wider at the end, narrower at the front||Short, exposing the abdomen tip||Standard|
|Diet||Carrion, maggots||Carrion, maggots||Carrion, maggots, fungi|
These carrion beetles play a vital role in ecosystems by decomposing dead animals and controlling insect populations, with each group having unique characteristics suited to their ecological niches.
Conservation Efforts and Threats
Endangered Species and Conservation Measures
Some species of carrion beetles are facing decline, mainly due to habitat loss and destruction.
Entomologists are actively working on conservation measures to protect these vital insects.
For instance, Nicrophorus investigator is one of the rare endangered species in the UK. Another one is the Nicrophorus americanus, which is native to America.
The threats these beetles face include:
- Habitat destruction
- Light pollution
- Fragmented populations
Conservation measures taken for carrion beetles include:
- Restoration of suitable habitats
- Limiting light pollution
- Encouraging landowners to create beetle-friendly environments
Reintroduction efforts play a significant role in the conservation of endangered carrion beetles such as the American burying beetle.
These large, predatory beetles have a relatively short lifespan, making them ideal candidates for reintroduction programs.
These programs usually involve the following stages:
- Captive breeding of the beetles
- Release of the beetles into suitable habitats
- Monitoring the released beetles’ populations
Reintroducing the beetles helps establish stable populations and supports overall woodland health.
Carrion beetles, with their unique ecological roles and fascinating behaviors, are indispensable components of our ecosystems.
They contribute significantly to nutrient recycling and natural decomposition processes, aiding in maintaining ecological balance.
Understanding their life cycle, interactions, and the conservation challenges they face allows us to appreciate their importance and the need to protect these often-overlooked creatures.
Their presence, though sometimes unnoticed, has far-reaching impacts on the environment and the intricate web of life.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about carrion beetles. Scroll down to have a look at some of them.
Letter 1 – American Carrion Beetles attracted to smelly mushroom
Subject: Bug on mushrrom
Location: Southern Manitoba Canada
August 18, 2012 8:13 pm
What’s the bugs name, and what’s the mushroom name (if possible)? There was a bad odour associated with the bug and mushroom – if that helps with the identification. Thanks.
Signature: Gerry Kramer
These are American Carrion Beetles, Necrophila americana. According to BugGuide: “Adults consume fly larvae (maggots) at carrion, as well as some carrion” and “Found on carrion and decaying fungi. Larvae eat carrion, larvae of flies and other carrion beetles. Eggs are laid singly on or near carrion.
They prefer larger carrion, Milne (5) states “rat-sized or larger”. Larvae hatch in a few days, feed in or under carcass, and pupate in a nearby soil cell. Larvae may prefer dried skin, bits of flesh after maggots have departed.” We are not certain if the odor was produced by the fungus rotting or if the mushroom had a bad odor itself.
Though most folks associate flowers with having a pleasant fragrance, there are plants like the Corpse Flower, Amorphophallus titanum, that have a foul odor which attracts flies and other insects that feed on decay. The same may be true of mushrooms.
The Corpse Flower has evolved so that the foul odor attracts insects that will pollinate it ensuring that it will produce offspring. The Huntington Gardens in San Marino, CA is a great place to view the Corpse Flower when it blooms.
We do not recognize the mushroom, but perhaps a mycologist will be able to provide that information.
Letter 2 – American Carrion Beetles
Sun, Jul 5, 2009 at 6:44 AM
I found these guys in my yard. They were feasting on the carcass of a red bellied water snake, but I have also seen them eating a copperhead carcass earlier this year. I live in Raleigh, North Carolina.
My yard is in the outer limits of 30 year old subdivision near a lake, several creeks, with an undeveloped heavy woodland/wetland area of over 2000 acres adjoining the property. These photos were taken on July 4, 2009 at around 8:30 pm.
They have been devouring this snake carcass for about 5 days now. They appear to be about 1 inch in length. They are black with white paterns on their neck. They have a broad back with black wings and are capable of flight. They seem to have a small black tail extending beyond their wings
I have lived in this area for 35 years and I have never seen these insects prior to this year. At first I thought they had white skulls on their backs, but now with the detail of photos I can see it is a different creepy pattern. So, what are these things?
Dear Bugging Out,
Your visitors are American Carrion Beetles, Necrophila americana. BugGuide indicates that they eat maggots and carrion and states that they are:
” Found on carrion and decaying fungi. Larvae eat carrion, larvae of flies and other carrion beetles. Eggs are laid singly on or near carrion. They prefer larger carrion, Milne (4)states “rat-sized or larger”.
Larvae hatch in a few days, feed in or under carcass, and pupate in a nearby soil cell. Larvae may prefer dried skin, bits of flesh after maggots have departed. Adults overwinter. ”
Over the years, we have gotten numerous reports of them being associated with the corpses of snakes, but we have also gotten photos of them with the carcasses of mammals and molluscs, and even photos of them feeding on fungus.
Letter 3 – American Carrion Beetle
black and yellow bugs
August 13, 2009
I saw these guys munching on some strange mushroom-like growth that appeared on the edge of the woods. The fungi and the bugs seemed to have appeared overnight. The bugs were quick but did not leave the mushroom even when I harassed them with my close contact. What are they?
These are American Carrion Beetles, Necrophila americana. Both adults and larvae consume carrion and the maggots that are attracted to the rotting flesh, but we have received other reports associating them with mushrooms.
Letter 4 – American Carrion Beetle
A strange one to me
May 15, 2010
Never saw one like this before. Three of them were beside and beneath a small snake that had gotten killed by the lawnmower a few days ago. Two appeared to be mateing I moved the little snake with a stick to get a better photo and they scattered in three different directions.
They look to have wings but did not attempt to fly instead they wanted to hid beneath the grass. They all were very shy, First glance I thought they were bumble bees from their size and color.
But after a closer look they clearly are not. I hope you can help with this one as I don’t have a clue. Thank you and have a wonderful day.
North Middle Tennessee
American Carrion Beetle
I sent a request for an ID along with two images this afternoon…I have since identified it from “Bug Guide” and your website as an “American Carrion Beetle” I should have did some searching before submitting my request. Thanks again and I hope this e-mail gets to you before you go to any trouble with my request. Have a wonderful day.
We do not consider answering and posting letters to be trouble, and we are most pleased to hear about readers like you who use our resources as well as those on BugGuide to identify creatures they are curious about. Your letter and photos of the American Carrion Beetle, Necrophila americana, are a wonderful addition to our site archives.
Letter 5 – American Carrion Beetle
Subject: What’s this bug?
October 31, 2013 3:48 am
I saw this bug near my garden just two days ago (29 Oct 13). He was walking on the ground.
American Carrion Beetles like the one in your photo are often found in association with small dead animals or rotting fungus.
Thanks!!! What a great site. Thanks for your Labor of Love.
Letter 6 – American Carrion Beetle
Subject: Black Beetle, Pale Yellow Thorax
Location: Hendersonville, NC
April 25, 2014 11:29 am
My wife shot this photo with her Droid. She says it was about the diameter of a penny, or maybe a nickel.
It was taken in Hendersonville, NC on 04/25/14.
Any idea what it is?
Signature: Mike Wright
Our Automated Response
Thank you for submitting your identification request.
Please understand that we have a very small staff that does this as a labor of love. We cannot answer all submissions (not by a long shot). But we’ll do the best we can!
Thanks, but I found it. American carrion beetle, Necrophila americana.
We haven’t received any images of American Carrion Beetles lately, so we are posting your submission.
Glad y’all are doing this sort of thing.
Letter 7 – American Carrion Beetle
Subject: odd beetle with white collar
Location: Lapeer, MI
August 3, 2014 5:29 pm
Can you tell me what type of beetle this is? It is about the size of a dime. I found it in my kitchen sink and it could have come in with some fresh cut flowers I brought last night. It reminded me of the hermit flower beetle, except for the white “collar”. Is it safe to release back in to my garden? Thanks for any information you can give me!
This is an American Carrion Beetle, Necrophila americana, and according to BugGuide: “Adults consume fly larvae (maggots) at carrion, as well as some carrion.” Perhaps there is a dead animal nearby, though they also feed on fungus including mushrooms.
Thanks for responding so quickly! I had not seen a beetle like that around my property before and was curious. I set it free and it immediately disappeared under some vegetation. All kinds of “new to me insects” around my yard this year!