Do Rove Beetles Fly? Unveiling the Mystery

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Rove beetles are fascinating insects commonly found on the soil surface across various habitats. These insects are known for their distinctive appearance, with short wing covers and a habit of raising their tails when running or disturbed, sometimes causing people to mistake them for small scorpions [1].

As the largest beetle family in North America, Staphylinidae consists of about 4,000 species of varied sizes and habits [2]. The question of whether rove beetles can fly is interesting to explore, considering their unique physical features and the diversity within their family.

Rove Beetles: An Overview

Family Staphylinidae

Rove beetles belong to the family Staphylinidae. Some key characteristics of this family include:

  • Shortened elytra (wing covers)
  • Exposed abdominal segments

The family Staphylinidae is the largest family of North American beetles, with about 4,000 species.

North America Native

As a native species in North America, rove beetles play an important role in ecosystems. They are predators, feeding on various insects and pests.

Common examples of rove beetles found in North America are:

  • Creophilus maxillosus (hairy rove beetle)
  • Platydracus maculosus
  • Ontholestes cingulatus

When observed, rove beetles can be seen running on the soil surface in different habitats. Some people might confuse them with small scorpions due to their habit of raising their tails while moving or when disturbed.

In comparing a few select rove beetle species found in North America:

Species Size Distinct Characteristics
Creophilus maxillosus (hairy rove beetle) Large (15-25mm) Covered in hair, black with orange-red marking
Platydracus maculosus Medium Elongated, black with red spots
Ontholestes cingulatus Medium Dark-colored, glossy body

Rove beetles can fly, but their short wing covers often lead to a preference for crawling and running rather than flying.

Physical Appearance and Identification

Elongated Abdomen

  • Rove beetles have a slender and elongated abdomen.
  • When disturbed, they often curl the tip of their abdomen upwards. 1

Wings and Elytra

  • They possess wings but have shortened front wings (elytra).2
  • The elytra may look like pads on the abdomen. 2

Colors and Patterns

  • Adult rove beetles are usually black or brown in color. 2
  • Some species may have glossy black, reddish-brown, or other color patterns. 3

Comparison of Rove Beetles and Earwigs

Feature Rove Beetles Earwigs
Abdomen Slender, elongated Somewhat elongated
Wings and Elytra Short elytra, wings Long elytra, wings hidden
Colors Generally black or brown Brown or reddish-brown
Reaction to Threats Curl abdomen tip upwards Use pincer-like cerci for defense

Habitat and Behavior

Soil and Moist Habitats

Rove beetles are commonly found in various habitats, mostly on the soil surface. These predators are especially attracted to moist environments. Some examples of habitats include:

  • Gardens
  • Forests
  • Stream edges

Decaying Organic Matter

These beetles play a crucial role in the ecosystem by consuming decaying organic matter, fungi, and pollen. They also prey on tiny arthropods found in organic debris and topsoil. Common prey for rove beetles:

  • Mites
  • Pupae
  • Maggots
  • Springtails

Nocturnal Activities

Rove beetles are primarily nocturnal creatures and tend to hide under objects such as bark, rocks, and leaf litter during the day. They become more active at night, searching for food and mates. As predators, they help control pest populations, making them beneficial for biological control in agriculture and horticulture.

Features of rove beetles:

  • Slender body
  • Shortened front wings
  • Curl abdomen upwards when disturbed

Characteristics of their behavior:

  • Predatory
  • Nocturnal
  • Fast runners

Comparison between rove beetles and earwigs:

Rove Beetles Earwigs
Short wing covers Long wing covers
Curl abdomen Straight abdomen
Lacks pincers Has pincers

Pros of rove beetles:

  • Help control pests
  • Act as decomposers
  • Beneficial for biological control

Cons of rove beetles:

  • May be mistaken for earwigs
  • Some species may feed on beneficial insects

Diet and Feeding Habits

Preying on Small Insects and Larvae

Rove beetles are known for their predatory habits and versatile diet. They primarily feed on small insects and their larvae, using their specialized mandibles to grasp and consume prey. For instance, they prey on shoreflies, fungus gnats, and thrips 1. Some examples of insects they prey on include:

  • Shoreflies
  • Fungus gnats
  • Thrips

Parasitoids and Predators

Rove beetles are not only predators, but they also act as parasitoids. In some species, the larvae infest and consume other insects from within. As versatile predators, rove beetles help in controlling the population of various pests in different ecosystems.

Pros and Cons of Rove Beetles As Predators

Pros:

  • Effective in controlling pest populations
  • Versatile diet reduces dependence on specific prey

Cons:

  • Can be harmful to some beneficial insect populations
  • May not specifically target desired pests

Scavenging Activities

In addition to being predaceous, rove beetles are also known for their scavenging activities. They search for dead insects and organic matter to feed on. This behavior helps in recycling nutrients and maintaining a balance in various ecosystems.

Table: Diet and Feeding Habits of Rove Beetles

Diet Type Examples Benefits Drawbacks
Preying on insects Shoreflies, Fungus gnats Controls pest populations Harmful to some beneficial insects
Parasitoids Varies between species Targeted pest control May not focus solely on desired pests
Scavengers Dead insects, Organic matter Nutrient recycling Does not directly target pest species

Reproduction and Lifecycle

Mating Process

Rove beetles, like other insects, have their own unique mating process. These beetles are usually nocturnal, which means their mating activities take place at night. Males locate females, engaging in courting and mating behaviors to attract their partners.

Eggs and Larval Development

After mating, female rove beetles lay their eggs in a suitable environment, ensuring the safety and protection of their offspring. Rove beetles have some similarities in appearance to earwigs, but they lack the pincers that earwigs possess. In the larval stage, rove beetle larva:

  • Feed on various small organisms
  • Resemble miniature adults, minus the wings
  • Go through several molts for growth and development

Pupating and Adult Stage

When rove beetle larvae have reached a certain size and development, they undergo pupation. During this stage, they:

  • Transform from the larval stage to the adult stage
  • Form a protective pupal case around their bodies

Once emerged as adults, rove beetles play a significant role in controlling pests, including being predators of parasitoids. The Omaliinae, a subfamily of rove beetles, are known to be beneficial insects that prey upon various pests in gardens and agricultural fields.

Features Rove Beetles Earwigs
Size Small to medium Small to medium
Wings Present but short Present
Nocturnal Yes Yes
Pincers Absent Present
Beneficial roles Predators Some species

Important Roles in Ecosystem

Biological Control Agents

Rove beetles, belonging to the Staphylinidae family, play an essential role in the ecosystem as biological control agents. They help suppress populations of pest insects and mites in various agricultural, horticultural, and forest crops.

For example, members of the genus Stenus feed on small insects and are particularly beneficial in controlling pests like aphids.

Features of Stenus beetles as biological control agents:

  • Predatory nature
  • Feed on small insects

Pros of using Stenus beetles in biological control:

  • Environment-friendly
  • Reduces need for chemical pesticides

Cons of using Stenus beetles in biological control:

  • May require careful management to be effective
  • May not completely eliminate pests

Beneficial Insects

In addition to acting as biological control agents, rove beetles are also considered beneficial insects. They contribute to maintaining the balance within the ecosystem by preying on harmful pests.

Characteristics of rove beetles as beneficial insects:

  • Predatory habits
  • Attack and feed on pest insects and their larvae

Comparison between rove beetles and other beneficial insects:

Insect Type of Pest Control Preferred Prey
Rove Beetles (Staphylinidae) Biological Control Agents Pest insects, larvae
Ladybugs (Coccinellidae) Biological Control Agents Aphids
Green Lacewings (Chrysopidae) Biological Control Agents Aphids, mites

In conclusion, rove beetles are valuable components of the ecosystem due to their roles as both biological control agents and beneficial insects, helping to control pest populations and maintain a balanced environment.

A Diverse Rove Beetle Subcategory

Terrestrial and Aquatic Species

Rove beetles, belonging to the family Staphylinidae, comprise a vast array of species, with over 4,000 species in North America alone. These beetles are characterized by their elongated bodies and a unique adroitness when it comes to movement. Contrary to popular belief, rove beetles can fly. They have shorter elytra compared to other beetles, leaving their abdomens exposed. This can lead to people confusing them with small scorpions.

The rove beetle family contains both terrestrial and aquatic species. Terrestrial rove beetles are often found on the soil surface in different habitats, while aquatic species thrive in water ecosystems.

Comparison table between terrestrial and aquatic rove beetles

Features Terrestrial Rove Beetles Aquatic Rove Beetles
Habitat Soil surface Water ecosystems
Movement Crawling Swimming
Elytra (Wing Covers) Short Short

Parasitic Relationships

Some rove beetles engage in parasitic relationships. For example, certain species lay their eggs in the nests of solitary bees. When the rove beetle larvae hatch, they feed on the bee larvae and the pollen provisions meant for the bees.

A few key characteristics of rove beetles with parasitic relationships include:

  • Laying eggs in the nests of other insects
  • Feeding on host larvae and food provisions
  • Impacting the host population negatively

In summary, rove beetles are a diverse group, with species that can fly and thrive in terrestrial or aquatic habitats. Some species engage in parasitic relationships with other insects, showcasing the complexity and variation in their behaviors and living conditions.

Rove Beetles in Literature and Science

Scientific Research

Rove beetles are fascinating insects that have piqued the interest of researchers and scientists. For instance, their unique appearance and behavior have led to many investigations into their roles as beneficial predators. These insects have proved their merit by suppressing pest populations in various agricultural, horticultural, and forest ecosystems.

As research continues, rove beetles are often seen as adroit hunters and effective in controlling pest populations. For example, they’re known to attack house fly maggots, illustrating their predatory prowess.

Rove Beetle Lists

In the world of entomology, understanding and classifying different species of insects is crucial. Literature on rove beetles often includes comprehensive lists and classifications to help identify these creatures within the diverse Coleoptera family.

Here are some key features of rove beetles listed in bullet points:

  • Belong to Staphylinidae family
  • Elytra reduced, exposing several abdominal tergites
  • Predatory insects
  • Elongate and short-winged
  • Shiny brown or black in color

When it comes to examining rove beetles, their ability to fly is a topic worth mentioning. Rove beetles do possess wings, but they’re often hidden beneath their very short wing covers. While not all species of rove beetles are known to fly, their concealed wings may be used in some instances, especially when escaping predators or attempting to reach new habitats.

Interesting Facts and Observations

Rove beetles are found on the soil surface in various habitats. Many people mistakenly confuse them with small scorpions due to their raised ‘tails’ when running or disturbed 1. These beetles also resemble earwigs but lack the prominent ‘pincers’ found on earwigs2.

These fascinating insects are part of the Staphylinidae family, which is the largest family of North American beetles, boasting about 4,000 species3. Most species are small, and while they are common, they are not well-studied.

Some rove beetles are known to visit flowers, feeding on pollen and sweet floral secretions4. In certain tropical areas, very specialized interactions exist between Magnolia flowers and a limited number of beetle species that effectively pollinate these flowers5.

Despite being part of the largest family of North American beetles, their ability to fly remains a topic of interest. Here are some characteristics of rove beetles:

  • Shortened elytra (wing covers) that expose abdominal segments6
  • Elongated, shiny brown or black bodies
  • Range in size from ¼ to 1 inch
  • Scorpion-like posture with the tip of the abdomen held in the air7

Rove beetles are also known to have ocelli, which are simple eyes, consisting of single lenses that provide them with basic light sensitivity8. Ocelli are different from compound eyes, which have multiple lenses and provide a sharper visual perception.

In conclusion, rove beetles are a diverse and fascinating group of insects. They have unique physical characteristics, and their ability to fly is an intriguing subject.

Footnotes

  1. Wisconsin Horticulture 2 3

  2. North Carolina State University 2 3 4

  3. Entomology and Nematology, University of Florida 2

  4. Beetles and Pollination – Maryland Agronomy News

  5. Beetles and Pollination – Maryland Agronomy News

  6. Rove Beetles (Staphylinidae) – Wisconsin Horticulture

  7. Rove beetles | Hortsense – Washington State University

  8. Rove Beetles (Staphylinidae) – Wisconsin Horticulture

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 – Gold and Brown Rove Beetle

 

Wasp looking bug
Location: Knob noster, mo
August 6, 2011 4:23 pm
A cinder block was moved and we found this odd looking little guy. He seems very aggressive for sure, brings his back end up like a scorpion when he gets upset. He also has wings.
Signature: Creepedbybugs

Gold and Brown Rove Beetle

Dear Creepedbybugs,
We hope that the information we will provide for you will make you somewhat less creeped out by bugs.  This is a Gold and Brown Rove Beetle,
Ontholestes cingulatus, which we identified on BugGuide, which indicates it is “Large for a rove beetle. Dark brown and hairy. Clumps of hair forms dark spots on much of body. Yellow hair forms “belt” under thorax, covers parts of last abdominal segments. Head wider than pronotum. Eyes large, prominently placed on sides of head. Found on carrion and fungi. Often turns yellow tip of abdomen upward when walking.”  They are a harmless species and they are often associated with dead animals.  BugGuide also notes:  “Adults eat maggots, mites, beetle larvae. Larvae feed on carrion, fungi.”

Letter 2 – Creechie Bug: Rove Beetle in Arizona

 

Critter by the River
Tue, May 19, 2009 at 2:46 AM
Hey I sent this in earlier this month and realized it may not have gone through as I didn’t receive an email confirmation. I found this critter by a stagnant pond near the bank of the Verde River in Cottonwood, Arizona at 5/5. I was taking photos of tadpoles when it wandered into my view. This is the only clear photo I got of him, sadly; the rest came out blurry. I haven’t seen another like it before or since, and I’ve been back out there twice since that date.
It is less than a centimeter long, with an up-curved abdomen that ends in a point. It otherwise resembled an ant. If the photo is not good enough shoot me an email and I will attempt to sketch it for you as accurately as I can remember. Curiosity is burning me up, let me know if there’s anything else I can do to help!
Justen, Cottonwood, Arizona
Cottonwood, Arizona

Rove Beetle
Rove Beetle

Hi Justen,
This is a Rove Beetle in the genus Paederus.  We first got letters regarding this genus from Cameroon and other parts of Africa where it is known as a Creechie Bug.  The Paederus Rove Beetles, according to BugGuide:  “contain a toxic chemical (pederin) in their hemolymph which causes contact dermatitis in humans, usually as a result of slapping the beetle and crushing it against exposed skin. The affected area becomes red, swollen, and itchy, causing the skin to peel when scratched. Outbreaks of Paederus dermatitis have occurred in Africa, Asia, and South America.
Historically, extracts of Paederus beetles have been used by the Chinese since at least the year 739 in the medicinal treatment of boils, nasal polyps, and ringworm.”  They are found throughout North America.

Letter 3 – Dead Rove Beetle from England

 

Subject: Whats this
Location: Warwickshire England
September 2, 2014 2:53 am
I found a bug in my home and have never seen this before , please can you identify it it was found in rugby Warwickshire ,on 31st of August 2015
Thanks in advance
J Powell
Signature: J Powell

Rove Beetle
Rove Beetle

Dear J Powell,
Wow, is Warwickshire a portal to the future???  Found in 2015???  This is a beneficial Rove Beetle in the family Staphylinidae, but we are uncertain of the species.  According to BNHS YounGnats:  “There are over 1100 different rove beetles in UK.”  According to the Empire Pest Control site:  “This casual intruder is associated with the forest environment for the whole of it’s life, however they do enter homes seeking shelter. Common in UK around field and forestry areas. Are not known for feeding on regular household food stuffs. Despite their somewhat aggresive appearance they pose no threat to people.”  The description continues with:  “What this predator is really looking for are insects, small invertebrates. It also catches maggots and other insect larvae. Will also feed on old decaying forest mushrooms and escaping sap on tree trunks.”
  We don’t really want to know why your individual appears bent into an unnatural position, though we suspect Unnecessary Carnage.

Letter 4 – Gold and Brown Rove Beetle

 

Golden stripes and patch, looks like a nymph
August 8, 2009
I was working at the local paintball field when I saw this little guy flying around. Being a bug nut I had to catch it to take pictures. I put him in the freezer to cool down as he was capable of flight and was quite energetic. Unfortunately for the little fellow, I left him in to long and he passed away. I’ve seen other insects like him at the field but with much longer abdomens and overall larger bodies that pulsated very noticeably as they breathed.
Christopher Kukowski
Rushford, MN

Gold and Brown Rove Beetle
Gold and Brown Rove Beetle

Hi Christoper,
You only need to keep an insect in the freezer for about 5-10 minutes to slow its metabolism enough to get a good photograph.  This is a Gold and Brown Rove Beetle, Ontholestes cingulatus
According to BugGuide, it is:  “Large for a rove beetle. Dark brown and hairy. Clumps of hair forms dark spots on much of body. Yellow hair forms “belt” under thorax, covers parts of last abdominal segments. Head wider than pronotum. Eyes large, prominently placed on sides of head. Found on carrion and fungi. Often turns yellow tip of abdomen upward when walking.

Gold and Brown Rove Beetle
Gold and Brown Rove Beetle

Wow, thank you very much!  I looked up rove beetles online and that is what I now believe the other larger insect are that I’ve seen flying around there.  I think it was hard for me to find what insect this was because I would have never guessed they were beetles, then again they did have hard shells covering their wings.  I was curious to see if these guys could sting me so I dissected the little guy and found no stinger 🙂  Also not only was it very pretty with the very reflective gold striped and patch on its bum but under its shell was a very brilliant green/blue iridescent color.
Thank you again Dan!

Letter 5 – Gold and Brown Rove Beetle

 

Subject: Yellow-bellied duff runner? Northern MN
Location: Superior National Forest, Minnesota
August 13, 2012 5:38 pm
Hello,
I work on the Superior National Forest in northern Minnesota and during the past few summers have continued to come across this peculiar insect. It has six legs, appears to have chewing mouth parts, is usually about 1” long, and has hidden wings. It flies around the understory in mixed hardwood forests, landing on leaves/stems and drops into the duff and runs off quite quickly whenever I get too close. The underside of it’s abdomen is bright yellow, and I’ve seen several specimens twitch and raise the tip of the abdomen (ovipositors?) almost menacingly. It’s such a bizarre insect I have no clue where to start with ID. So far, I’ve been calling them ”yellow-bellied duff runners”, but would love to know what they actually are! Thanks in advance for your help!
Signature: Nick

Gold and Brown Rove Beetle

Hi Nick,
As much as we love the name you have coined, Yellow Bellied Duff Runner, the real name for this unusual beetle is the Gold and Brown Rove Beetle,
Ontholestes cingulatus.  According to BugGuide:  “Adults eat maggots, mites, beetle larvae. Larvae feed on carrion, fungi” and “Eggs are laid near carrion or fungi. Larvae feed on carrion or fungi, presumably. Pupate in chambers in soil nearby. Given the collection dates of spring and fall, it seems likely that they overwinter as adults.”  The individuals you observed sound like they were searching for food.  This large Rove Beetle, like most of its relatives, is perfectly harmless despite the menacing posture it strikes when threatened.  There is a group of Rove Beetles, though, known as the Paederus Rove Beetles in most parts of the world or Creechie Bugs in Africa that can cause a nasty case of contact dermatitis.  The Paederus Rove Beetles sport aposomatic or warning coloration in bold patterns of orange and black.

Letter 6 – Gold and Brown Rove Beetle

 

Subject: Mystery bug
Location: New Paltz, NY
May 15, 2013 9:16 am
I don’t know what this thing is! I found it near my front door sitting in the waterer for my chickens…I don’t think it hatched there….the waterer had been empty until a recent rain. It’s difficult to tell from the photo but it has large mandibles…no wings, and is kind of fuzzy.
Signature: Chrissy

Gold and Brown Rove Beetle
Gold and Brown Rove Beetle

Hi Melissa,
This is a Gold and Brown Rove Beetle,
Ontholestes cingulatus.  According to BugGuide:  “Large for a rove beetle. Dark brown and hairy. Clumps of hair forms dark spots on much of body. Yellow hair forms “belt” under thorax, covers parts of last abdominal segments. Head wider than pronotum. Eyes large, prominently placed on sides of head. Found on carrion and fungi. Often turns yellow tip of abdomen upward when walking.”

Update:  June 11, 2013
Thanks to a comment from Alfred, we now know that this is Platydracus maculosus, the largest native Rove Beetle in North America.  See BugGuide for additional information.


Letter 7 – Hairy Rove Beetle

 

Confused in Indiana
Hi Bugman,
I figure the thing that erks you most is when people send you a photo of an insect for identification without first checking to see if the bug is on your site. I believe I am NOT one of those people. I’ve looked through just about every page and if this little critter is listed, I’ve totally overlooked him. It was brought to me by a co-worker that lives near a creek which is flooded right now. We’re in Evansville, Indiana. Any information will be greatly appreciated! Sincerely,
Sean Kempf

Hi Sean,
Rove Beetles are atypical as far as beetles are concerned, and many people would not even recognize them as beetles. Your Rove Beetle is a Hairy Rove Beetle, Creophilus maxillosus.

Letter 8 – Hairy Rove Beetle

 

Bugs in basement
Location: Cinicinnati, OH
June 30, 2011 7:43 pm
Hello,
I have seen several of these bugs crawling around in my basement. Although I thought I saw wings on them, I never see them fly. I thought I saw pincers on their head, but don’t see one in this picture. Could that be a pincer on it’s bottom? I am curious to know what this bug is and if it’s harmful or dangerous. Seems to have yellow colored stripes. At first I thought I was looking at some sort of bee, but it is just crawling around and not behaving like one!
Signature: DN

I think I got it
Location: Cincinnati, OH
June 30, 2011 8:15 pm
I just submitted a picture to the site. I will attach it again. After some reading online, I think it might be a Embioptera. What do you think?
Signature: DN

Hairy Rove Beetle

Dear DN,
This is a Rove Beetle in the family Staphylinidae, and we believe it is a Hairy Rove Beetle,
Creophilus maxillosus, which we matched to images on BugGuide.  There is no way we can bring this up delicately, so we will just quote BugGuide which indicates Hairy Rove Beetles feed  “on carrion and dung.”  We suggest that you look in your basement for potential food sources.

Thank you.
that makes sense. We recently had a dead mouse, that then caused a fly infestation that finally has gone away. but i am sure we have a few dead maggots hiding in the basement!

Letter 9 – Hairy Rove Beetle

 

Subject: Big flying unknown insect
Location: SE WISCONSIN
July 11, 2017 7:53 pm
I just moved into a new home this month. Today, I have seen 4 (possibly 5, might have seen the same one more than once) of these bugs. I have never seen this kind before and have had no luck with Google. All the ones I’ve seen are rather large, about a quarter size or more. I’m worried there’s some kind of nest or something since I’ve seen so many in one day. Also worries if they sting or anything, as I have 4 small children in the home. I am located in southeast wisconsin, in a rural area with farm fields all around us. Please solve this mystery for me!
Signature: KP

Hairy Rove Beetle

Dear KP,
We identified your Hairy Rove Beetle,
Creophilus maxillosus, thanks to Arthur V. Evans’ excellent book Beetles of Eastern North America where it states:  “Adults appear in late spring, again in late summer;  feed on maggots at carcasses in open, wooded, and coastal habitats;  not uncommon in urban and suburban habitats.”  Here is a BugGuide image for comparison.  According to BugGuide:  “food maggots and adult flies, also other arthropods” and the habitat is “grassy and open forested habitats, lake/ocean shorelines; on carrion (typically, larger carcasses), rarely on dung, compost, or at lights.”  If you are finding them indoors, perhaps there is a dead animal in immediate vicinity of the house.  From the descriptions, we would go on the record that this is a beneficial predator that helps to control populations of flies.  Rove beetles are not venomous, but Evans’ book does state:  “Produce an irritating defensive chemical at the tip of the abdomen.”

Letter 10 – Hairy Rove Beetle

 

Subject: Bug
Location: Boston, MA
July 12, 2017 12:23 pm
Dear bugman,
We found this insect in Boston, Massachusetts. Any ideas on what it could be? He likes to hang out and rub his backside against the container. Its hard to see, but he has white/gray stripes (2 bands). His wings are yellowish and translucent.
Thank you,
Signature: Curious jr entomologist

Hairy Rove Beetle

Dear Curious Jr Entomologist,
We just posted another image of a Hairy Rove Beetle a few hours ago.

Letter 11 – Hairy Rove Beetles: Dead, but with justifiable cause

 

What is this bug that has invaded my culture and is it dangerous to my black soldier fly larva?
September 25, 2009
Hi, I have found and killed 30-40 of these bugs in my black soldier fly larva culture. They appear to be some sort of mimick cause they look very similar to adult soldier flies. They do not have wings or stingers. I have seen copulation so I am assuming they are adults. They have mandibles similar to an ant or beatle. Please let my know if these guys are simply a pest competing with the soldier fly larva for food or are the fly larva being preyed upon by this bug? And, if known, how do I get rid of them without damaging the culture or detering the attraction of the wild adult soldier flies laying eggs?
Jason P.
Dallas Texas

Hairy Rove Beetles
Hairy Rove Beetles

Hi Jason,
These are Hairy Rove Beetles,  Creophilus maxillosus, and they are predators.  According to BugGuide, they are found on dead animals and dung and they are:  “predaceous on fly larvae in [cattle] dung and on carrion.
In most situations, we would tag your letter as Unnecessary Carnage, but in this case, we are torn. Since you are doing bio-composting with the Soldier Flies, you don’t want predators, even beneficial insects, invading your culture.   Sadly, we cannot provide any suggestions for keeping the Rove Beetles from the fly culture.

Hairy Rove Beetles
Hairy Rove Beetles

Letter 12 – Gold and Brown Rove Beetles prey upon Blow Flies

 

Subject: Help! Totally stumped with this insect!
Location: Newfoundland, Canada
September 16, 2013 5:37 pm
Hi there! I’m writing from Newfoundland, Canada. Today, sept 16, 2013 I came across an insect I have never seen before. I’m usually good with bugs – but this one has me stumped!
While walking through an alder bed with goldenrod I first observed the insect flying around and then landing on goldenrod. It looked a d behaved wasp like, pumping up and down. I never seen anything like it. Then I found a group of them ! They were attracted to a group of flies that had landed on something small and deceased. The flies were landing and walking on the carcass and the insects in question were skulking around – and then I watched one sneak up and grab a fly! Then I realized they were all doing this.
I had considered Robber Fly – but the antenna look totally wrong, so does everything else! But the behaviour is very similar! It’s predatory. I’d estimate the insect to be almost an inch in length.
Sorry for the long letter but I hope the details will help! Thank you so very much!!!
Signature: Jenny in Newfoundland

Brown and Gold Rove Beetle eats Blow Fly
Gold and Brown Rove Beetle eats Blow Fly

Dear Jenny,
This is one of the most exciting letters we have received in a very long time, and we are featuring it because of your thrilling personal observations and the gorgeous photos you have taken as proof of your observations.  In our untrained minds, you have made a significant scientific observation.  This is a Gold and Brown Rove Beetle,
Ontholestes cingulatus, and it appears to be preying on a Blow Fly.  According to BugGuide, the Gold and Brown Rove Beetle can be identified because it is “Large for a rove beetle. Dark brown and hairy. Clumps of hair forms dark spots on much of body. Yellow hair forms “belt” under thorax, covers parts of last abdominal segments. Head wider than pronotum. Eyes large, prominently placed on sides of head. Found on carrion and fungi. Often turns yellow tip of abdomen upward when walking.”  BugGuide also states its habitat is:  “on carrion wherever found” and “Eggs are laid near carrion or fungi,” but this is a rare BugGuide Information Page that does not discuss what the adult Gold and Brown Rove Beetle eats.  The large eyes are mentioned, and large eyes placed on the sides of the head would make a good hunter.  We suspect that the reason the Gold and Brown Rove Beetles are attracted to the Carrion is to prey upon flies as well as to lay eggs.  The developing Fly Maggots would compete with the larval Gold and Brown Rove Beetles’ food source, so eating the flies before they can breed on the carrion probably helps more Rove Beetles to survive to the adult stage.  Thanks again for your exciting submission.  We are going to feature it on our scrolling header as well.

Brown and Gold Rove Beetle preys upon Blow Fly
Gold and Brown Rove Beetle preys upon Blow Fly

Oh that’s so fascinating! Thank you for getting back to me so quickly!
It was just the most incredible thing watching those beetles hunt the flies. It took me by surprise at first! So I grabbed my camera and decided to photograph them grabbing and eating the flies. They moved so swiftly. They actually snuck up on the fly and then just grabbed them! There were about 7 of them around the carcass, and each one had a fly in it’s legs! So interesting! Especially since I never seen one before! I could have watched them for hours. Thank you so much for identifying this insect for me! I couldn’t figure out what it was and was going crazy! I’m so happy!
Many thanks!
Jennifer

 

Authors

  • 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.

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  • 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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Tags: Rove Beetles

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10 Comments. Leave new

  • bugman, thanks for helping my friend Jason and thanks again for identifying my first black soldier fly a few years ago. 🙂

    Reply
  • jamey paridon
    May 1, 2013 4:16 pm

    Found wht i guess is a devils couch horse? In soddy daisy tn today its belly is black and yellow

    Reply
  • Alfred F Newton
    June 3, 2013 7:53 am

    This is actually Platydracus maculosus, the largest rove beetle in the US, not the slightly smaller Ontholestes cingulatus. Note the head is narrower than the pronotum, unlike Ontholestes where it is wider.

    Reply
  • Alfred F Newton
    June 3, 2013 7:56 am

    This is also Platydracus maculosus, not Ontholestes cingulatus!

    Reply
  • I think I may have caught one of these in my house in Newfoundland, it killed a brown recluse spider with a single strike, I have a photo of it but I’m not entirely sure how to add it to here, any questions are welcome, there have been quite a few “odd” insects around here this summer.
    -Travis

    Reply
  • I think I may have caught one of these in my house in Newfoundland, it killed a brown recluse spider with a single strike, I have a photo of it but I’m not entirely sure how to add it to here, any questions are welcome, there have been quite a few “odd” insects around here this summer.
    -Travis

    Reply
  • I found this similar bug in Lee’s summit, mo. It was dried up in the bottom of a box from storage.

    Reply
  • Amanda L Highley
    July 14, 2020 6:42 pm

    I have seen 2 flying around me while sitting in backyard for the last week. They land in the grass and crawl around and go down in a hole. Late evening. They fly slow like they are almost too heavy to fly far. I thought it was a stinger on the butt but thankfully it’s not. Live in Cedar Hill in Jefferson County MO and am 53 years old and have NEVER seen one before.

    Reply

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