Rove Beetle: All You Need to Know in a Nutshell

The Rove Beetle is a fascinating insect found all around the world, with over 63,000 known species. These beetles can be easily recognized by their slender body and short wing covers, which reveal the majority of their flexible, elongated abdomen. They are highly adaptable creatures, inhabiting diverse environments such as forests, gardens, and coastal areas.

Rove Beetles are beneficial insects for both gardeners and farmers, as they feed on other insects considered pests. As natural predators, they play a vital role in maintaining the balance of our ecosystem. Despite their petite size, these beetles have impressive abilities, such as the capacity to release defensive chemicals from their abdomen when threatened.

Here’s a brief comparison table showcasing the characteristics of Rove Beetles:

Identification and Appearance

Rove beetles are fascinating insects that you might come across in various habitats. Identifying them can be quite simple once you know a few distinguishing features. These beetles are typically brown or black, and their bodies can range from 1/4 to 1 inch in length, with an elongate and slender appearance. Their short front wings and exposed abdomen made them easily recognized amongst other insects.

When observing a rove beetle, you may notice their unique tails. These beetles have a habit of raising their tails when disturbed or running, which might lead to confusion with small scorpions. However, one of their distinct features is their antennae, which sets them apart from other insects like earwigs that might have a similar appearance.

Some of the key features of rove beetles are:

• Brown or black color
• Slender and elongated bodies
• Short front wings, exposing abdomen
• Raised tail when disturbed or running
• Antennae

To give you an idea of how rove beetles differ from other insects, here’s a comparison table:

Now that you’re aware of the key features and characteristics of rove beetles, identifying them in your garden or in the wild should be easier for you. Remember, these beetles play a vital role in controlling pests, such as mite and aphid larvae, making them beneficial for maintaining a healthy ecosystem.

Classification and Diversity

Rove beetles belong to the order Coleoptera and class Insecta. They are part of the family Staphylinidae, which is one of the largest beetle families with over 63,000 recognized species worldwide. Within this family, there are various genera, subfamilies, and tribes that make up the diverse group of rove beetles.

For example, the subfamily Aleocharinae contains more than 12,000 described species, which feed on various types of prey and inhabit a wide range of environments. Another subfamily, Apateticinae, consists of fewer species, but is characterized by colorful patterns and unique features.

While it’s impossible to cover every subfamily and tribe in this short section, let’s take a closer look at some key characteristics that make rove beetles stand out among other insects:

• Most rove beetles are black or brown.
• They have flat and slender bodies.
• They possess very short wing covers that expose most of the abdomen.
• Rove beetles are often found in soil, under stones and leaves, and near compost piles.
• Many are active predators, with some species feeding on mites, beetle larvae, aphids, and small caterpillars.

To better understand the diversity within the Staphylinidae family, it’s helpful to compare subfamilies and tribes. Here’s a basic comparison of the Aleocharinae and Apateticinae subfamilies:

As you learn more about rove beetles, remember that their diversity is vast and this is just a brief introduction to the classification and diversity of this fascinating insect group.

Habitat and Distribution

Rove beetles can be found in various habitats, usually in moist environments. They are commonly found on the soil surface in places like the United States, Europe, and across North America ¹. In these areas, you might come across these beetles in gardens, forests, or even near compost piles ².

These fascinating insects are highly adaptable and active predators. They are nocturnal, meaning they are active during the warm nights ³. They can overwinter, which means they can survive through the winter in stages such as larvae, pupae, or adults ³.

As you explore the world of rove beetles, you’ll discover that their habitat extends beyond just moist environments. They can also be found in a wide range of environments, from dry deserts to wet rainforests. Keep in mind that their preferred habitat may vary depending on the specific species.

Overall, the habitat and distribution of rove beetles are quite diverse, making them a fascinating group of insects to study and learn about. They play a crucial role in controlling the population of other insect pests, which is why their presence is appreciated by gardeners and farmers alike.

Diet and Predatory Behavior

Rove beetles can be a useful addition to your garden. As predatory insects, they feed on a variety of small organisms. Their diet largely consists of pests that may cause harm to the plants.

For instance, they are known to target mites, maggots, earwigs, aphids, and root maggots. Some rove beetles even feed on fungi, algae, or plant mulches. If you notice a reduction in pests, the presence of rove beetles can be a contributing factor.

However, not all relationships with rove beetles are entirely positive. While they do help control harmful insects, they may also prey on beneficial ones like bees. This means that you need to carefully consider their impact on your garden.

In summary, rove beetles can be both friend and foe to your plants. Their predatory behavior can help keep pests in check, but they might also inadvertently harm beneficial insects too.

Life Cycle and Reproduction

The life cycle of a rove beetle comprises four stages: eggs, larvae, pupa, and adults. Let’s explore each stage in detail.

Eggs: Female rove beetles lay small clusters of eggs near potential food sources for the larvae. These eggs are off-white in color and hatch in about 3 to 4 days¹.

Larvae: After hatching, the larvae of most rove beetle species are highly active. They search for food in sheltered, slightly moist habitats below ground or in soil litter². There are three larval stages, each maturing before moving on to the next stage³.

Pupation: Following the larval stages, rove beetles enter the pupal stage. Pupation usually occurs in concealed locations, like under rocks or logs.

Adults: Upon completion of pupation, rove beetles emerge as fully developed adults. They are usually shiny brown or black in color, with a unique appearance due to their short wing covers⁴.

Rove beetles have a relatively fast life cycle, with a complete progression from egg to adult taking around three weeks at 77° F⁵. As adults, females continue to lay eggs, repeating the life cycle process.

Morphological Features

The Rove Beetle is an interesting insect with several unique morphological features. Let’s discuss some of these features in more detail.

Mandibles: Rove beetles possess strong mandibles for chewing. These mouthparts are specifically designed for their feeding habits, as they mostly feed on other small insects and decomposing plant materials.

Pincers and Abdomen: Although Rove beetles are sometimes confused with small scorpions or earwigs due to their appearances, please note that they do not have the large “pincers” that earwigs possess. When alarmed or scurrying around, they raise their abdomens, resembling a scorpion-like posture¹.

Front Wings and Wing Covers (Elytra): An easily recognizable feature is their shortened front wings (called elytra), which expose most of the abdominal segments². This distinct appearance separates them from other beetle families.

Some key characteristics of Rove beetles are:

• Strong, chewing mandibles
• Scorpion-like raised abdomen when threatened
• Shortened elytra, exposing most abdominal segments

Understanding these morphological features can help you identify Rove beetles when you come across them in various habitats, such as in soil or under rocks and leaves³. Remember, Rove beetles are friendly insects that play an important role in the environment by consuming small pests and decomposing plant materials.

Rove Beetles as Biological Control

Rove beetles are beneficial insects that help manage pest populations in various environments. They serve as both predators and scavengers, attacking harmful pests and consuming decaying materials.

These beetles are advantageous in biological control because:

• They naturally control pest species
• They are native to North America
• They provide an eco-friendly alternative to chemical pesticides

When considering biological control, the rove beetle’s ability to target pests becomes essential. For instance, these beetles consume various pests that are harmful to your crops, such as aphids, mites, and small insects.

However, there are a few things to note when using rove beetles for pest management:

• They don’t attack every type of pest
• They are not available for purchase in North America, making it harder to implement them on a wider scale

Despite these limitations, rove beetles can be valuable allies in keeping pest populations in check. By maintaining a healthy population of these beneficial insects, you can promote a more balanced ecosystem and protect your crops from harmful pests.

Toxin and Defense Mechanisms

Rove beetles have clever ways to protect themselves from predators. One of their defense mechanisms involves producing toxins. Let’s dive into their toxin and defense strategies.

Pederin: Pederin is a powerful toxin found in some rove beetles, especially those within the Paederus genus ¹. This chemical compound is used as a protective measure against potential predators. When threatened, the rove beetle can release pederin, which deters attackers[1]. Pederin is notorious for causing skin irritation and blisters in humans upon contact ².

Chemical Defense: Rove beetles have a variety of chemical defenses. Apart from pederin, they may produce other chemicals that ward off predators ³. These chemicals can vary depending on the species, but they are generally unpalatable or toxic to predators. By releasing these chemicals, rove beetles can ensure their safety in their habitat.

Mimicry and Behavior: Rove beetles use more than just toxins to defend themselves. They employ mimicry and deceptive behavior to deter predators as well. For instance, these beetles raise their abdomens when threatened, resembling scorpions or ants ⁴. This makes predators perceive them as a dangerous opponent, ensuring safety for the rove beetle.

To sum it up, rove beetles have multiple defense strategies, including the production of pederin and other chemicals, and employing mimicry and behavior to deter predators. These adaptations help them thrive in their environment.

Dealing with Rove Beetles

Rove beetles can be found both indoors and outdoors, typically in areas with decaying matter and debris. These insects feed on small insects and can be beneficial for controlling pests in your garden.

To deal with rove beetles outdoors, consider the following steps:

• Remove decaying matter and debris from your yard to reduce their habitat.
• Keep vegetation well-trimmed to make the area less appealing for them to reside.
• Monitor your garden closely, as rove beetles can help with pest control by feeding on smaller insects.

If you find a rove beetle indoors, it’s often best to let them be, as they typically do not harm humans or plants. However, if you want to deter them from entering your home, take the following precautions:

• Seal any gaps around doors and windows to prevent beetles from entering your home.
• Clean up spills and crumbs promptly to discourage them from staying indoors.
• Store food in airtight containers to keep them away from food sources.

Here are some key features and characteristics of rove beetles:

• They have elongated, slender bodies with short wing covers.
• Rove beetles are usually black or brown in color.
• They are predators that feed on small insects, which can make them beneficial for pest control.

Overall, rove beetles can be helpful in controlling smaller insect pests in your garden. By taking preventive measures as needed and keeping your outdoor and indoor spaces clean, you can successfully coexist with these interesting insects.

Notable Species

The world of rove beetles is vast and diverse. In this section, we’ll focus on a few notable species that you might come across in your garden or while exploring nature.

Ocypus olens

The Ocypus olens, also known as the devil’s coach horse, is a larger species of rove beetle. You can identify it by its shiny black body and unique defensive posture. When threatened, it raises its abdomen in a scorpion-like manner but don’t worry, it’s not venomous.

This rove beetle is known for its predatory habit, feeding on various garden pests like slugs, snails, and other insects. Having Ocypus olens in your garden can be beneficial for natural pest control.

Pictured Rove Beetle

Another fascinating species is the pictured rove beetle or Thinopinus pictus. This beetle is nocturnal, and you may spot it hunting for prey on sandy beaches along the Pacific coast of North America. Its vibrant orange and black markings not only make it visually striking, but also help to distinguish it from other species in the genus.

Genus Stenus

The genus Stenus consists of many rove beetle species that are fast and agile predators, feeding on smaller insects and pests. One of the unique features of these beetles is their ability to propel themselves across water surfaces with a substance called stenusin. It allows them to glide effortlessly in search of prey, demonstrating incredible adaptability to varied environments.

Overall, rove beetles can be a valuable part of your garden’s ecosystem, helping to naturally control pests and maintain balance. Recognizing and appreciating these fascinating beetles can enhance your understanding of the complex relationships between various organisms in your backyard habitat.

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 – Tumbling Flower Beetle, not a Rove Beetle

Black insect on Queen’s delight
Sun, May 24, 2009 at 3:52 PM
Can you help me ID this small black insect on Stillingia sylvatica (“Queen’s-delight”? It was on most of the flowers. Because of the pointy tail I was guessing it was immature? An instar of a wood-boring beetle perhaps? (Just guessing). Thanks for your help.
Joan
Georgia, Appling County

Dear Joan,
Our money is on this being a Rove Beetle in the family Staphylinidae. According to BugGuide, there are “In North America, about 17 subfamilies, 313 genera, 3100 species.” We hope to get a second opinion on this being a Rove Beetle. According to our Audubon Guide: “most Rove Beetles and their larvae oprey upon mites, other insects, and small worms. They are usually found on mushrooms, flowers, or under bark.”

Correction: from Eric Eaton Mon, 25 May 2009 08:36:54 -0700 (PDT)
Daniel:
Nope.  It is a “tumbling flower beetle,” family Mordellidae.  Can’t tell more than that from the image alone.
Eric

Thanks for the correction Eric.  We can link to BugGuide which states:  “Body humpbacked, more or less wedge-shaped; broadest at front; head is bent forward, attached ventrally; abdomen pointy, extending beyond elytra. Hind legs enlarged. They kick and tumble about when disturbed. Black or gray, some brown; hairy, sometimes light patches of hair form pattern. Antennae short to moderate, threadlike, sawtoothed or clubbed. “

Letter 2 – Transvestite Rove Beetle from Costa Rica

Stange black insect
Location:  Costa Rica
September 21, 2010 11:05 pm
Hi,
I hope you guys can help me!
Recently I went on a trip in February to Costa Rica for two weeks. I took many bugs pictures and this is the only I cannot identify.The pictures were taken by a large river. The insect was about one inch long, maybe a little less. It had wings which it flew with. The back end of it, it was able to move much like a scorpions tail, which is the part I found most fascinating… Its pincers were also quite large for its size.
No guide I asked knew what it was, all assumed it was a scorpion till I told them it flew.
Any help would be much appreciated! 🙂
Signature:  Christine Claes

Hi Christine,
This is some species of Rove Beetle in the family Staphylinidae, though we are not certain if we will be able to determine an exact species for you.  According to BugGuide: “Thin, active beetles with shortened elytra that do not, at first glance, resemble beetles. In typical form, body appears to be divided into four parts when viewed from above. Family characteristics:
body shape typically elongated, with parallel sides
elytra short (about same length as pronotum, or only slightly longer; wings are functional in most), typically exposing 3-6 (usually 5-6) abdominal segments, though abdomen concealed in a few
coloration usually dark but some brightly colored
antennae thread-like or clubbed
tarsal formula variable, usually 5-5-5 (sometimes 4-5-5, 5-4-4, etc.)
Some species run with abdomen curled up over thorax as if it were a stinger but no rove beetle has a stinger.“

Identification of Transvestite Rove Beetle Courtesy of R. Randy Hoffman
Today’s “Strange black insect” is (I kid you not!) the “Transvestite Rove Beetle”
September 22, 2010 6:42 pm
Cue Tim Curry to put on the fishnet and grab the microphone, Daniel! After scouring through lots of Google images for “Staphylinidae” + “Costa Rica” for the rove beetle posted as today’s “Strange black insect”, I get an excellent match at http://scrubmuncher.wordpress.com/2010/01/06/scoundrels-2/. This has to be a specimen of <i>Leistotrophus versicolor</i>, the Transvestite Rove Beetle. The blog post has a fascinating discussion of how some males of the species imitate females. “Don’t get strung out by the way that I look,
Don’t judge a book by its cover.” 🙂
Signature: W. Randy Hoffman

Dear W. Randy Hoffman,
Thank you first for tracking down this identification, and perhaps even more for the brilliant pop culture citation.  We really don’t want to give too much away regarding the content of Daniel’s book, but there is a section on male Cockroaches that imitate females to gain the upper hand on dominant males.  It is a chilling account that includes dismemberment.  The link you provided is a great place to start, and it includes this information:  “Males of this rove beetle are divided into two types, normal butch specimens and small, effeminate ones. The small, effeminate males can find honey-pots, but they have little hope of defending them against the bigger males, so their chances of building a harem are next to nothing. These males have evolved another means of making sure they pass their genes onto the next generation. They sneak past the normal males using their effeminate appearance as a disguise and under the harem owner’s nose they have it away with the females he has been so carefully guarding. This strategy is almost flawless, but now and again the transvestite male is caught prancing around in the harem by the owner male and the only way he can avoid being torn limb from limb is by assuring the aggressor of his femininity and giving in to a ‘mating’.  One sore behind later, the transvestite male carries on sneakily copulating with the females in the harem, only slightly more nervous for his unpleasant experience.” We also wanted to research this Transvestite Rove Beetle, Leistotrophus versicolor, a bit further.  We have verified the information you provided us by locating another website from Colorado State department of Entomology that has a 1995 paper by Robin Corcoran posted online entitled Intraspecific Sexual Mimicry in Insects.  That paper contains this information:  “MIMICRY TO GAIN ACCESS TO MATES  Large males of the tropical rove beetle, Leistotrophus versicolor, establish territories on bonanza resources, vertebrate dung and carrion (Forsyth and Alcock 1990).  Females attempting to feed on flies attracted to these sites are courted and usually mate with the territorial males.  Some males in this species have adopted an alternative strategy.  These males are considerably smaller, have smaller and differently shaped mandibles, and effectively mimic females.  This enables them to gain access to larger male’s territories, soliciting courtship from the territorial male and even mating with females while being courted by the resident male.  Resource defense polygyny enables large males the opportunity to monopolize mates.  This strategy has led to the evolution of alternative male reproductive tactics in which small males can successfully deceive larger males by mimicking females.  Small males, however, also exhibit behavioral flexibility, mimicking females only in the presence of larger males but attacking and driving off smaller rivals.”   Again, thanks for this wonderful addition to our website.

Glad you liked my ID text; also glad you were able to verify the information. One other point mentioned in the blog post that I found fascinating was that these beetles exude a rotten-smelling chemical from the pygidial glands in their abdomen, use their heinie to rub the stuff on a leaf, and wait to snack on the flies that it attracts. “I see you shiver in antici…pation!”
Randy

Letter 3 – Two Rove Beetles: Water Skater and Crablike Rove Beetle

Minuscule Rove Beetles(?) in Oklahoma!!!
March 5, 2010
Hi,
Today I found these tiny beetles in my pool (in central Ok.). I think that they were rove beetles, but I’m not sure. They were both about 2mm in length, with long, thin abdomens. One had a head that definitely looked like a rove beetles, but the other had a more rounded head with smaller eyes. Their elytra did not cover their abdomens and they would both periodically retract their wings. One was black and the other was dark brown. Since I found them in my pool I don’t know what kind of habitat they would normally be living in. Thanks for any help you can provide in identifying these little guys.
Josh Kouri

Update
March 8, 2010
Hi,
Several days ago I sent you some pictures of rove beetles that I found. After I sent you the pictures I decided to check BugGuide and I think I might have Identified them myself. I think that the black one with the more rove beetle-like head is a species of water skater. The other one looks like a crab-like rove beetle, possibly /Byroporus rufescens. /I’m not sure that those I.D.s are correct, but they are my best guess. Thanks,
Josh

Hi Josh,
Sorry we did not respond to your original letter, but we have been very busy, and the quantity of mail and identification requests is beginning to increase with the approach of spring.  Thank you for taking the time to research the identities on your own.  We know that searching through the incredibly well organized archives of BugGuide can be a daunting task.  We agree that based on images posted to BugGuide, one of your Rove Beetles is a Water Skater.  The images on BugGuide of the Crablike Rove Beetle Byroporus rufescens also resembles your photograph.  We concur with the identifications you have made, at least to the family level.

Letter 4 – Unknown Rove Beetle from England

Subject: What’s this bug
Location: England
March 28, 2017 2:33 pm
Hi
My brother has just found 3 of these I’m his house, and is worried they are cockroaches!!!!
Can you help with what they are?
We are in England and the midlands area.
Thank you
Signature: Regards Jacquie

Dear Jacquie,
This is not a Cockroach.  It is a beneficial, predatory Rove Beetle in the family Staphylinidae, but alas, we have not had much luck determining a species name.  There are many species of Rove Beetles illustrated on NatureSpot, but none that looks quite like yours.  According to Mark Telfer’s Website:  “There are about 1,134 species in this family, as delimited in the Duff (2012) checklist. This one family thus contains over a quarter of the 4,072 species of beetle.”   We believe those statistics refer to the British Islands.