Hanging Thief: All You Need to Know for Your Curious Mind

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The Hanging Thief is a fascinating insect known for its unique behavior and intriguing appearance. Belonging to the robber fly family (Asilidae), these predatory insects are commonly found in North America and play a vital role in controlling various pest populations. With their distinctive elongated body and intriguing hunting methods, the Hanging Thief captures the attention of enthusiasts and casual observers alike.

One of the most striking features of the Hanging Thief is its habit of hanging from a single leg while consuming its prey. This behavior earned the insect its common name and fuels curiosity about its lifestyle and diet. As ambush predators, Hanging Thieves feed on a range of insects, including flies, bees, and wasps, which they catch mid-flight using their strong legs and sharp, piercing mouthparts.

In terms of appearance, Hanging Thieves have:

  • Elongated, slender bodies
  • Large, prominent eyes
  • Strong, spiny legs

Their unique predatory behavior and diverse diet play an essential role in maintaining ecological balance in their ecosystem. By controlling the populations of various insect species, Hanging Thieves ultimately contribute to the overall health of their habitats.

Identification and Classification

Genus Diogmites

Diogmites is a genus of robber flies belonging to the family Asilidae. They are commonly known as “hanging thieves” due to their unique habit of hanging by their front legs while consuming prey. Features of the genus Diogmites include:

  • Long, slender body
  • Strong, spiny legs
  • Prominent proboscis for piercing prey

Some examples of species within the genus Diogmites are:

  • Diogmites neoternatus
  • Diogmites angustipennis
  • Diogmites salutans

Family Asilidae

The hanging thieves belong to the family Asilidae, which consists of over 7,000 species of robber flies. Asilidae can be identified by their:

  • Robust body
  • Large, forward-facing eyes
  • Short, strong proboscis for piercing and sucking prey

In comparison to the other members of the family, Diogmites stand out due to their hanging behavior and long, slender body.

Subfamily Dasypogoninae

The subfamily Dasypogoninae is a part of the family Asilidae. Including the genus Diogmites, this subfamily is characterized by:

  • Predatory behavior
  • Short, dense hairs on the body
  • A preference for drier habitats
Family & Subfamily Notable Features Examples
Asilidae Robust body, large eyes Promachus, Laphria
Dasypogoninae Short hairs, dry habitats Diogmites, Dasypogon, Sarota

Overall, understanding the classification and identification of hanging thieves (genus Diogmites) clarifies their unique position within the family Asilidae and subfamily Dasypogoninae, setting them apart by their distinctive features and behaviors.

Physical Characteristics

Size and Appearance

The Hanging Thief is a large fly belonging to the robber fly family. Its key features include:

  • Typically 1/2 to 1 inch long
  • Slender body with long legs
  • Brown or grayish color

These flies are known for their aerial hunting skills and ability to catch their prey mid-flight.


The Hanging Thief has mouthparts adapted for piercing and sucking. The primary components include:

  • A proboscis for feeding
  • Sharp, needle-like structures for piercing

These mouthparts allow the fly to consume its prey effectively.

Compound Eyes

The fly’s compound eyes are one of its most notable features. They provide the Hanging Thief with:

  • Excellent vision for hunting
  • A wide field of view

The eyes are large, covering most of the head, and typically reddish-brown in color.


Another distinctive characteristic of the Hanging Thief is the mystax, a set of bristles located on its face. The mystax serves to:

  • Protect the mouthparts from damage
  • Stabilize prey during feeding

Overall, the Hanging Thief’s unique features make it an efficient predator in its natural habitat.

Distribution and Habitat

United States

The Hanging Thief is a type of robber fly commonly found throughout the United States. They prefer habitats such as:

  • Forest edges
  • Grassy areas
  • Meadows

Mississippi River

The Mississippi River region provides suitable habitat for Hanging Thieves due to the abundance of:

  • Riparian vegetation
  • Large insect populations as prey

Range and Numbers

Hanging Thieves have a wide distribution and can be found across North America. While exact numbers are not known, they are considered to be a common species.

Feature Hanging Thief Other Robber Flies
Habitat preference Forest edges, grassy areas, meadows Varies depending on species
Range United States, especially near Mississippi River Different species found worldwide

Pros of Hanging Thieves:

  • Control insect populations by preying on them
  • Help maintain ecosystem balance

Cons of Hanging Thieves:

  • May bite humans when threatened
  • May invade personal space if they are disturbed

Behavior and Feeding Habits

Predatory Nature

The Hanging Thief, a species of robber flies, is a skilled predator that mainly preys on various insects. Examples of its prey include:

  • Bees
  • Wasps
  • Dragonflies
  • Mosquitoes

These predators use their strong legs to catch their prey in mid-flight, demonstrating outstanding agility.

Ambush Predator

Hanging Thieves are ambush predators, using a sit-and-wait strategy to capture their prey. They often perch on branches or leaves, blending in with their surroundings before attacking unsuspecting insects.

Characteristics of ambush predators:

  • Excellent camouflage
  • Patience
  • Quick attack reflexes

Hunting Techniques

The Hanging Thief uses two main hunting techniques to catch its prey:


When a suitable target enters its sight, the Hanging Thief takes off and chases it down in mid-air, capturing it using its powerful legs.

Perch and Wait

As previously mentioned, the Hanging Thief is an ambush predator. It patiently waits on a leaf or branch for prey to come close, then launches a surprise attack.

Hunting Technique Pros Cons
Chase Can track and catch agile insects Requires more energy
Perch and Wait Energy efficient Limited to nearby prey

Using a combination of these hunting techniques allows the Hanging Thief to efficiently find and consume various prey, contributing to its reputation as an effective and voracious predator.

Life Cycle and Reproduction

Larval Stage

  • Larvae of the Hanging Thief (also known as Diogmites missouriensis) are found in damp soil near water sources, such as a rush.
  • They are predators, feeding on smaller insects.


  • A Hanging Thief larvae might hunt small insects like aphids in its environment.

Adult Stage

  • Adult hanging thieves are known for their eerie hovering behavior in mid-air.
  • They use long legs to snatch prey, such as bees or flies, out of the air.

Comparing Larval and Adult Stages:

Larval Stage Adult Stage
Habitat Damp soil near water sources Air, close to food sources
Feeding Habits Predatory, on small insects Predatory, capturing larger insects

Characteristics of Hanging Thieves:

  • Agile fliers
  • Prey on various insects
  • Can hover in mid-air

Pros of Hanging Thieves as Natural Predators:

  • Reduce pest insect populations
  • Contribute to maintaining a balanced ecosystem

Cons of Hanging Thieves as Natural Predators:

  • May catch beneficial insects along with pests

Overall, understanding the life cycle and reproduction of the Hanging Thief can help us appreciate their role in the ecosystem and their unique behaviors in both larval and adult stages.

Interaction with Humans

Bite Prevention

The Hanging Thief, a type of robber fly, may bite humans if mishandled or threatened. To prevent bites:

  • Avoid handling the bug directly
  • Wear gloves if necessary

Bites usually cause pain and swelling but are rarely serious.

Importance in Ecosystem

Hanging Thieves play a vital role in their ecosystem. Some benefits include:

  • Controlling pest populations
  • Serving as food for larger predators

Let’s compare Hanging Thieves to another predator, for example, dragonflies:

Characteristic Hanging Thief Dragonfly
Prey Insects Insects
Hunting style Ambush Aerial
Habitat Stems, branches Water, vegetation

Hanging Thieves, with their flexible legs, can easily grasp onto stems and branches when hunting. They are very agile predators that help maintain balance in their ecosystems and are generally not a cause for concern among humans.

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 – Hanging Thief


St. Louis, MO unidentified bug
Location: St. Louis, MO
August 1, 2011 7:44 pm
I saw this bug in my backyard. It flew past me and landed on our deck railing. At first I thought it was a wasp but as I looked closer I realized it was something else. The bug was very docile – it did not move much at all as I photographed it. It almost looks like a dragon fly wasp hybrid. No stinger that I could see.
Sorry a couple of the photos are not sharp – was using my iPhone camera.
Signature: jredington

Hanging Thief

Hi jredington,
This is a Robber Fly in the genus
Diogmites, commonly called a Hanging Thief.  It gets its name from its habit of hanging by a single leg while eating the prey it has snatched from the air using its long legs like a basket.  Here is a photo from our archives that illustrates a Hanging Thief eating.

Letter 2 – Hanging Thief


E-gads, what’s this? Bucks County, PA
August 6, 2009
Hi Mr. Bugman. I’m a mom of 2 and had just strapped my kids into their seats today – August 6th – when I noticed this who-knows-what-kinda-bug on my dashboard. It was a little less than an inch long and was near my a/c vent. It didn’t appear to want to fly anywhere and didn’t seem agitated but the close-up of it made me think of the movie, “The Fly”!
I drove home and had forgotten about it. Now I’m wondering 3 things: What is it? How did the poor thing get in our minivan (and how can it get out?!) ? And is it at all harmful?
Thanks so much! LOVE your site! And best of luck on the book 🙂
Bucks County, PA (35 miles north of Philadelphia)

Hanging Thief
Hanging Thief

Hi Sharon,
This awesome Robber Fly is known as a Hanging Thief.  It probably entered your minivan the same way you did, through the door, or perhaps through an open window.  It can leave the same way.  We haven’t heard any reports of people being bitten by Hanging Thieves or other Robber Flies, but they do bite their prey and it is entirely possible if a person mishandles one of them, the person may be bitten.  There is a big difference between “will it bite” and “can it bite” and we would say that it is not inclined to bite, but it might bite.  Your photos are amazingly wonderful.

Letter 3 – Hanging Thief


Subject: Looked like a HUGE Wasp but is a Mosquito?
Location: Aberdeen, NJ (Central NJ)
August 20, 2012 7:59 am
I was at a local shop (in Aberdeen, NJ) with my daughter yesterday and happened to see this HUGE flying insect outside the window. I could have sworn this was the largest Wasp I had ever seen but it really appears to be a Mosquito?
Can you please help me out by telling me what this is?
I don’t know what it is but I’m calling it a descendant of Mothra. (Somebody call Godzilla!!!) I would HATE to have that thing bite me!
Signature: Fred from NJ

Hanging Thief

Hi Fred,
This Hanging Thief is a Robber Fly in the genus
Diogmites.  You were astute to notice the similarities between the Hanging Thief and a mosquito because both Robber Flies and Mosquitoes are in the same insect order, Diptera.  Hanging Thieves are formidable predators that often prey upon wasps and bees that they catch on the wing.

Letter 4 – Hanging Thief


robber fly
This robber fly was perched on the window seal at The Oyster House on Mobile Bay, and was really freaking out the wait staff there. I assured them this was no giant mosquito that would suck them dry in one bite.
Bill Giles
Powder Springs GA

Hi Bill,
This is one of the Robber Flies in the genus Diogmites, the Hanging Thieves.

Letter 5 – Hanging Thief


I entered this before
I sent this before but I don’t know if you got it. I photographed this bug last summer in Northern NJ. I have never seen anything like this before and if I didn’t have the one photo of it, I don’t think I could have convinced anyone else of it’s existence! It was only about an inch or so big, I had to zoom in to get a good photo of it. I only got the one photo before it flew away. Please help me identify this bug!
Sue Dericks
Byram, NJ

Hi Sue,
This is a Robber Fly that is known by the colorful name of the Hanging Thief.

Letter 6 – Hanging Thief


We live in West Tennessee and found this strange bug in our garage. In the picture, it’s resting on top of a flashlight. Thanks,

Hi Cody,
This looks like one of the Robberflies in the genus Diogmites, the Hanging Thieves.

Letter 7 – Hanging Thief


Help me PLEASE
Hi Bugman,
All I can say is WOW!!!!! What a WONDERFUL site. The BEST bug site I’ve seen. Thank you. I love to photograph all sorts of “Creepy Crawlers and Fliers” I live in Chicago, Illinois, I can’t find any information on this UFB (unidentified Flying Bug). It’s body length is about 1 1/4″ to 1 1/2″ long, Fly’s pretty fast and doesn’t sit still for photo’s. It took a a lot of shot’s to get this one. I’m sorry it’s not a very good shot. It’s quite intimidating when this thing flies at your head though. The branch that it’s sitting on is about the size of a mans index finger. Thanks again for having a GREAT site.

Hi Glenn,
Thanks for the compliment. This is a Robber Fly in the genus Diogmites, the Hanging Thieves. Because of the bright orange coloration, we believe this is Diogmites neoternatus.

Letter 8 – Hanging Thief


This bug is my friend
Hi Bugman,
We haven’t noticed creatures like these in the Central Valley of California until the last year or so. It’s possible that they’ve been here all along but I’m positive not in my back yard. What is particularly striking about this bug is it’s tendancy to hunt and kill Paper Wasps that lurk in my lawn and land on my pool. I really like this bug. I would like to know more about this one.
Friend Of The Wasp Hunters

Dear Friend,
This is a Robber Fly in the genus Diogmites, known as the Hanging Thieves. They are skilled fliers and hunters as your observations have proven.

Letter 9 – Hanging Thief


what type of flying bug is this?
I have enclosed several pictures. This bug landed on our truck and didn’t seem to mind us as he stayed around for a while. The bug was found in Dunwoody, Georgia during the morning hours of July 4th, 2008. Any ideas on to what type it is would be appreciated. My mother thinks it is a mosquito. Lord, help us if it is!
Jennifer Williams

Hi Jennifer,
Your insect is a Robber Fly known as a Hanging Thief in the genue Diogmites. These are amazing predatory insects that get their common name from their habit of hanging by one leg while eating. BugGuide has a nice selection of species identified, but we don’t feel confident to identify your specimen beyond the genus level.

Letter 10 – Hanging Thief


Loud flying wasp-mosquito-spider
July 23, 2009
Can you tell me what this is? Because I’m convinced that there is a mad scientist somewhere missing this experiment!
While coming home from work four nights ago, my brother in law accidently let this bug in. It flew in and went up our stairs making a VERY loud buzzing sound. He initially thought it to be a common Mosquito Hawk because of it’s erratic flying pattern, but then it landed long enough for him to get a good look and he discovered it was not. Hopefully it’s not some kind of killer bug because it landed on his head at one point!. We live in South Texas so we’re pretty used to odd bugs, but this one was weird enough to warrent an ID request. He was able to capture in a Gatorade bottle and I got out my macro lens for some closeups.
II included the best of the photos that I was able to take in hopes of an ID. It looks like a GIANT mosquito to me! Sorry for the last picture being so unclear. There were water drops left in the bottom of the bottle and given the thickness of the plastic that was the best shot I could get of it’s face.
It is brownish red in color, has a 3 segmented body, and it appears that all 6 of it’s legs were attatched at the middle segment. As I said before, it made a VERY loud buzzing sound and didn’t seem very happy to be detained! His face looked like that of a mosquito in that he looked like he could either draw blood or nectar with it. His eyes are huge and black and protruded from the sides of his head. From above, I think he looks like a wasp because of the wing shape and segmented body but the design on his back is strange, similar to a house spider. He even had black back hairs that you can see in the side profile picture! Gross! And he was a “sturdy” bug as well. I could feel it everytime he hit the side of the container! I was a bit scared of him so it was hard to take the pictures! He was so big I was just sure he was going to burrow through the plastic and get me!
Please help me figure out what this unusual critter is!
Just Wondering
South East Texas

Hanging Thief
Hanging Thief

Dear Just Wondering,
Your brother in law let a Hanging Thief in the house.  A Hanging Thief is a Robber Fly in the genus Diogmites.  All Robber Flies are predators and the Hanging Thief gets its common name from its habit of hanging from one or two legs while feeding.  There is an awesome photo on BugGuide that illustrates the feeding habits of the Hanging Thief.
  Hanging Thieves do not bite people routinely, but that is not to say that they can’t bite people if carelessly handled.  We believe they are capable of biting, but we have never gotten a report nor read any accounts of it actually happening.

Letter 11 – Hanging Thief


Robber Fly
October 8, 2009
I believe this is a robber fly but would like to get your expert opinion. I have not seen one with green eyes.
m zapata
Flower Mound, Denton County, Texas

Hanging Thief
Hanging Thief

Dear m zapata,
Yes, this is a Robber Fly.  We are nearly certain it is a Hanging Thief in the genus Diogmites.  Though it does not look like an exact match, it does resemble Diogmites discolor which is pictured on BugGuide.  We will check with Eric Eaton to see if he can identify the species.  Your photos are stunning and this is an exquisite creature.

Hanging Thief
Hanging Thief

Update from Eric Eaton
No, I don’t know robber flies that well, but if it is not a species of Diogmites then it is certainly a closely-related genus.

Letter 12 – Hanging Thief


Requesting the correct name for this insect.
February 16, 2010
This insect that I would like a name for is seen in the summer months. I have heard that they either eat flies, mosquitoes, or bees? I have seen this insect in South Eastern North Carolina
South East North Carolina

Hanging Thief

Dear A.G.,
This is a Hanging Thief, a species of Robber Fly in the genus Diogmites.  They are predators, and they will eat flies, mosquitos and bees.

Awesome !!!  Thanks for the quick response !

Letter 13 – Hanging Thief


Location: South Florida (Pompano) 06/09/2011
June 9, 2011 11:28 pm
This bug looks like a cockaroach/yellowjacket. Very Strange and never seen before. Many of us have tried to figure it out but we’ve never seen it before! HELP!
Signature: Lisa

Hanging Thief

Hi Lisa,
This very distinctive insect is a Robber Fly in the genus
Diogmites, a group known as the Hanging Thieves because they often eat their prey while hanging upsidedown from a single leg.

very cool thank you. I thought it was Great Golden Digger Wasp!

Letter 14 – Hanging Thief


What kind of insect is this?
Location: North Texas, Denton Conty
July 9, 2011 1:31 pm
Found this insect on the windowsill. Never seen one before and just curious what it is?
Signature: George

Hanging Thief

Hi George,
This is a Robber Fly in the genus
Diogmites, and they are called by the common name Hanging Thieves.

Letter 15 – Hanging Thief


What is this thing?
Location: Lancaster, PA
July 22, 2011 2:18 pm
Seen this sort of little guy three times in the last few years, so he can’t be that prolific, from what I can tell. One got into my apartment forever ago and it flew around like a wasp, and flexed its abdomen as if it were trying to sting after I’d smacked him down. (No stinger though from what I can see.)
Then yesterday, there was one zooming around my workplace and dive bombing people. I tried to take him out, but he escaped me.
Is this little guy a sort of fly? His mouth parts and eyes remind me of a fly and the rest of him seems wasp like. He’s not really that small either. He’s about the size of a wasp. He flies sort of clunky too, unlike a fly.
Signature: The Creeped out One

Hanging Thief

Dear Creeped out One,
You are astute in your observations that the face of this Hanging Thief in the genus
Diogmites has the mouth parts and eyes of a fly because it is a Robber Fly in the family Asilidae.

Letter 16 – Hanging Thief


Bug identification
Location: chicago suburbs
July 28, 2011 3:41 pm
We live in the far western suburbs of Chicago (about a mile away is ”country”). This bug has been hanging out by our back (patio) door on and off for a week now. It is annoying. Does it sting or bite? What else can you tell me about it?
He is about as long as the diameter of a quarter. His legs are pretty thick and have ”hairs” on them. He kinda ”dances” around the door, but lands for brief times. He reminds me of something in the bee/hornet family, but I don’t see a stinger (by his coloring and the way he files).
Signature: Molly

Hanging Thief

Hi Molly,
This is a Hanging Thief, a genus of Robber Flies.  Other than it “hanging out” you didn’t indicate what it does that is so annoying.  Hanging Thieves are not an aggressive group, however, we acknowledge that they could probably bite a person if they were carelessly handled, an encounter you can avoid by simply ignoring them.  Hanging Thieves are predators and they catch flying insects to feed upon. 

Letter 17 – Hanging Thief


Unknown bug from Oklahoma
Location: Western Oklahoma
August 6, 2011 10:11 pm
I stopped at a gas station in Western Oklahoma (I believe it was Clinton, OK) and this bug was sitting on the ground next to the pump. It didn’t move the whole time I was pumping so I was able to grab my camera and take a photo. It was about 3 inches in length. I can’t find any matches online. Any help in providing an ID would be appreciated. Thanks!
Signature: -Gabe

Hanging Thief

Hi Gabe,
This is a Robber Fly, and we believe it is a Hanging Thief in the genus
Diogmites.  We have been receiving numerous identification requests for Hanging Thieves in the past few weeks.  We believe your individual looks very similar to this unidentified Hanging Thief from Texas posted to BugGuide.

Letter 18 – Hanging Thief


Subject: fat bodied crane fly maybe?
Location: Central Florida
May 22, 2012 11:04 pm
I moved to Florida, from the UK, a few years ago. Your website has been one of the most valuable resources! I will often scour the site for days researching bugs I’ve found while gardening and I’d like to feel a little of your knowledge has rubbed off maybe?! But I can’t find this bug – It was about an inch in total length and brightly coloured. I thought it was some sort of crane fly, but nothing seems to match. I would be so grateful if you could identify this one for me, many, many thanks,
Signature: Tanya

Hanging Thief

Hi Tanya,
You have the order correct, but this is not a Crane Fly.  It is a predatory Robber Fly in the genus
Diogmites.  They are commonly called Hanging Thieves because they often hang up-side-down from one leg while feeding.

Hanging Thief

Thank you so much!  We get the large black robber flies, but I’ve never seen one like this.  I like this guy, he’s pretty – maybe I can direct him towards our increase in deer flies this year as a meal source!!!!
Thanks again,

Letter 19 – Hanging Thief


Subject: What kind of bug is this?
Location: Naperville, Illinois
July 21, 2012 3:04 pm
Dear bugman,
I just took this picture of a bug on my balcony. I have never seen anything like it. It has six legs, kind of spiderish looking, but has wings, big eyes, and a black ”nose” or whatever you call it.
Signature: Heidi

Hanging Thieg

Hi Heidi,
This is a predatory Robber Fly in the genus
Diogmites, a group commonly called Hanging Thieves because they hang from a single leg while feeding.  We have gotten numerous identification requests for Hanging Thieves in the past week.

Thanks for your quick reply! After reading up about the Robber Fly, it makes sense. We have a wasp problem, and the Robber Fly preys on them.
Thank you!

Letter 20 – Hanging Thief


Subject: Dragonfly / Damselfly
Location: La Marque, Texas
November 2, 2012 10:58 pm
When i saw this in the yard, i couldnt decide if it was a dragonfly or damselfly. The body and wings made me lean more to a damselfly but the eyes and shampe of its mouth didnt quite fit. Any clue as to what this insect is?
Signature: Thanks in advance, Tx Finest

Hanging Thief

Hi again Tx Finest,
This is another Robber Fly, and more specifically it is a Hanging Thief in the genus

Letter 21 – Hanging Thief


Subject: Southeastern PA Insect
Location: SE Pennsylvania
July 25, 2013 4:44 pm
Hello! I failed to ID this on any site!
Here’s the deets*:
-Can fly (not gracefully) with its transparent, black-tinted wings
-3 dark brownish stripes/raindrops on its upper abdomen, running parallel with its body
-Drags its 2 back legs (of 6 total) behind it in a wasp-like way
-A bit bigger than a quarter
-Found under a bush; wasn’t aggressive nor fleeting, but kind of stupid. It would take a flutter hop or two when we excited it with a blade of grass.
*Yes, that was a pun. Thanks all!
Signature: Kait

Hanging Thief
Hanging Thief

Dear Kait,
Do not judge what your perceived to be a lack of grace in this Hanging Thief, a Robber Fly in the genus
Diogmites, too harshly.  While they may seem ungainly on the ground, Hanging Thieves are very adept aerial predators that take large prey, often wasps and bees, on the wing.  The common name Hanging Thief refers to their manner of feeding.  After catching their winged prey, Hanging Thieves alight and feed, often dangling from a single leg like a circus performer.  This posting will go live during our unexpected trip in early August.

Letter 22 – Hanging Thief


Subject: Robber Fly with Green Eyes?
Location: Northeast Florida
September 2, 2013 1:28 pm
I’ve seen this big flying insect a few times in the past couple of days but today I was able to get some photos when it landed on a vine. Its body was about 1.25 inches long (35 mm) and its green eyes were very noticeable. It looks like a Robber Fly, maybe a Hanging Thief? Or is it too big for that?
Signature: Karen in Florida

Hanging Thief
Hanging Thief

Hi Karen,
Your Robber Fly is definitely a Hanging Thief in the genus
Diogmites, and there are several species found in Florida with green eyes, so we don’t feel comfortable taking the identification to the species level.

Letter 23 – Hanging Thief


Subject: what is this?
Location: North carolina (central)
July 20, 2014 10:23 am
Please tell me name of this bug never have seen anything like it–was on my back porch
Signature: c santana

Hanging Thief
Hanging Thief

Dear c santana,
This impressive, predatory Robber Fly in the genus
Diogmites is commonly called a Hanging Thief because they frequently hang by one or two legs while feeding.

Letter 24 – Hanging Thief


Subject: I’ve never seen this bug before….
Location: Delaware
July 20, 2014 5:29 pm
I’d really like to know what this bug is, why I’ve been seeing them so often lately, and why I have not seen them before (if that’s possible to answer).
I live in Delaware (the state in the US) and this summer I’ve been seeing these everywhere I go.
Signature: ….I don’t really have a preference?

Hanging Thief
Hanging Thief

We just posted a lengthy description of a Hanging Thief.  As to why you have seen them recently, we can only respond that insect populations fluctuate due to weather conditions, food supplies and other factors.  Then again, perhaps you have just gotten more observant.

Letter 25 – Hanging Thief


Subject: It’s an ALIEN INSECT!
Location: Indianapolis indiana
August 8, 2014 3:13 pm
What in the HAIL is this insect? It was on my sweet corn. We live in Indiana. Thank you!
Signature: Bugs,

Hanging Thief
Hanging Thief

There is nothing alien about this magnificent, predatory Robber Fly in the genus Diogmites, commonly called a Hanging Thief.  It is a native genus.  This individual appears to be waiting to ambush some large flying prey, often bees or wasps.  The common name Hanging Thief is derived from the manner in which the predator hangs from a single leg while feeding on its captured prey. 

OMG! How COOL! Haha thank you. It was really terrifying because it would turn it’s head to look in my direction when I would talk.
I am a collector of praying mantids. And it was really interesting to me that this insect was able to turn his head like that. I thought I read somewhere that only praying mantids were capable of doing this. Do you know what I’m talking about? Thank you so so much! Very cool insect to have around in my garden!
Thanks again!

Today was quite the day for large Robber Flies.  We have four new postings, including another Hanging Thief and two Red Footed Cannibalflies.

Haha. How funny!
So what is it called when an insect can move it’s head/neck joint around like this one and praying mantids do?

Hmmm.  Flexible perhaps?  According to National Geographic on mantids:  “They have triangular heads poised on a long ‘neck,’ or elongated thorax. Mantids can turn their heads 180 degrees to scan their surroundings with two large compound eyes and three other simple eyes located between them.”  No special adjective is used to describe the flexibility.  According to Featured Creatures:  “Robber flies are opportunistic predators, their diets often reflecting prey availability in a particular habitat. Shelly (1986) reported that of the nine Neotropical Asilidae species he studied, diet constituents were more than 85% composed of insects from the orders Diptera, Coleoptera, Hymenoptera, Homoptera, and Lepidoptera. Furthermore, larger species tended to consume a greater diversity of prey taxa. Robber flies generally establish a perching zone in which to locate potential prey. Perching height varies by species, but generally occurs in open, sunny locations. Asilidae seize their prey in flight and inject their victims with saliva containing neurotoxic and proteolytic enzymes. This injection, inflicted by their modified mouthparts (hypotharynx), rapidly immobilizes prey and digests bodily contents. The robber fly soon has access to a liquid meal, which is generally consumed upon returning to a perched position.”  No mention is made of head rotation.  We had better luck on the Asilidae Homepage Information on Robber Flies Morphology where multiple experts are quoted.  According to Lehr (1988): “Head flattened, transversely rounded or slightly oblong, mobile” and according to Majer (1997):  “Head is relatively short and broad with more or less convex occiput, freely moveable.”  To there you have it.  According to the experts, the head is either “mobile” or “freely moveable.”  P.S.  We also just posted an image of mating Red Footed Cannibalflies which brings to total Robber Fly postings today to five.

Letter 26 – Hanging Thief


Subject: Mega Mosquito
Location: Lewisville, Texas
August 8, 2014 8:54 pm
I found this bug 3 feet outside my apartment. I live in Lewisville, Texas. I took this picture on August 8, 2014. I really want to know if this bug is dangerous. The rail it is sitting on is about an inch and a half thick. It’s really intimidating. I got as close as I could without making it fly off. I hope it will be enough to identify this bug.
Signature: Any

Hanging Thief
Hanging Thief

Dear Any,
This seems to be “the day of the Robber Flies” as this is the third image of a Robber Fly we are posting this morning.  This particular Robber Fly is a Hanging Thief in the genus
Diogmites.  They are stealth predators that generally pluck their prey out of the sky, and their prey often includes large flying insects like wasps and bees.  Robber Flies are not aggressive towards humans, but we imagine if someone was foolish enough to try to capture one by hand, a bite might result.  Texas is home to numerous species of large Robber Flies.  With a bit of imagination, and a slightly different camera angle, a “creative” photographer could take an image that appears as though this individual was waiting to prey upon a luckless human emerging from that parked car, but that would be an example of phantasmagoria. 

Thank you very much for the information. I can rest easier knowing that this bug won’t come after me. I like them a whole lot more knowing they will eat bees and wasps, as I am allergic to their stings. I lived my whole life in Texas but this was the first time I had seen a Robber Fly. A person screaming at the fly in the photo would have been epic. Who knows. Maybe another one will land on the railing. 🙂 

Letter 27 – Hanging Thief


Subject: i need to identify this insect
Location: fenton, missouri
July 28, 2015 3:49 pm
Can you please tell me what kind of bug this is?
Signature: however you want

Hanging Thief
Hanging Thief

This is a Hanging Thief, a predatory Robber Fly in the genus Diogmites.

Letter 28 – Hanging Thief


Subject: My morning mailbox surprise
Location: Dayton, OH
September 3, 2015 5:47 am
Good morning! Today, this little guy was waiting to ask me how badly I really wanted to check the mail today. He hung around long enough for me to get a couple of pictures, did an impressive flyby in the general direction of my face, and took off.
I don’t know if it’s at all relevant, but there was also a large house centipede behind the mailbox, which was another first.
Signature: Amorette

Hanging Thief
Hanging Thief

Dear Amorette,
We don’t believe there is any connection between the House Centipede and the Hanging Thief, a large predatory Robber Fly.  Hanging Thieves, though predators, tend to take prey on the wing and House Centipedes would not be part of their diet.  They often feed while dangling from a single leg, hence the common name Hanging Thief.

Letter 29 – Hanging Thief


Subject: I’ve never seen this before
Location: Carbondale Il 62901
July 4, 2016 11:19 am
Hi Bugman,
Great website! I am writing because I saw this bug on my screen door today and I’m curious what it might be. It’s been raining for about 3 days here and when it flew away it kind of floated.
Signature: Ayla

Hanging Thief
Hanging Thief

Dear Ayla,
Don’t let its floating flight fool you.  Like other large Robber Flies, this Hanging Thief in the genus
Diogmites is a formidable predator, easily taking large Wasps or Bees on the wing.  The common name Hanging Thief arises from this group’s preference to feed while hanging from a single leg.

Hanging Thief
Hanging Thief

Wow! Thanks for the quick response and information! Keep up the good work.
Ayla M. Amadio, MA
Research Archaeologist

Letter 30 – Hanging Thief


Subject: Help what’s this bug
Location: Sherman, tx
July 18, 2016 4:38 pm
This creepy critter landed on my car, I live in Sherman Texas.
Signature: Kristi

Hanging Thief
Hanging Thief

Dear Kristi,
This formidable predator is a Robber Fly in the genus
Diogmites, a group known collectively as Hanging Thieves.

Letter 31 – Hanging Thief


Subject: Identification request
Location: Iola, KS
July 17, 2016 9:59 am
Hi! I encountered this strange insect on my front porch yesterday and I don’t think I have ever seen anything like it before. It looks almost like some weird kind of mosquito/wasp cross to me. My aunt suggested that it might be a pregnant deer fly, but it doesn’t match up with the pictures I’m finding online. I was hoping maybe you could help me find out what it was?
Signature: Gary Reeder II

Hanging Thief
Hanging Thief

Dear Gary,
This is a Robber Fly in the genus
Diogmites, a group known as the Hanging Thieves

Letter 32 – Hanging Thief


Subject: unknown insect
Location: Central Illinois
July 31, 2016 1:36 pm
We live in central Illinois and have seen this insect from time to time, but we do not know what it is. I hope you can identify it for us. Thank you.
Signature: Marsha Nelson

Hanging Thief
Hanging Thief

Hi Marsha,
This Robber Fly is commonly called a Hanging Thief because they frequently eat their prey while hanging from one leg.

Letter 33 – Hanging Thief


Subject: Beautiful bug
Location: Bradenton, Florida
August 6, 2016 1:07 pm
About 1 inch long.
Signature: Kathleen

Hanging Thief
Hanging Thief

Dear Kathleen,
This Robber Fly is commonly called a Hanging Thief because of their habit of hanging from one leg while devouring prey they have captured on the wing.

Letter 34 – Hanging Thief


Subject: Large Horsefly…ish???
Location: Raleigh, NC
August 11, 2016 8:09 pm
I’ve attached a photo (that I promise I took) of an insect in Raleigh, NC in June. It stands about an inch tall and is a little more than an inch long. I’m working on a “Critter Album” for my little girls, and I’m trying my best to ID all that I can. Any help would be greatly appreciated!
Signature: Sam the inquisitive dad

Hanging Thief
Hanging Thief

Dear San the inquisitive dad,
Your Critter Album sounds like an awesome way to educate your girls about the wonders of the natural world.  This is a Robber Fly in the genus
Diogmites.  They are commonly called Hanging Thieves because they frequently hang from one leg while feeding on prey.

Letter 35 – Hanging Thief


Subject: what am I dealing with
Location: Mount solon, va
August 19, 2016 11:45 am
Dear bug man we live out in the country of Augusta county and have noticed an odd type wasp looking bug… my son who is 6 was stung the past two days about 6 times in two different periods… I saw this guy nearby and feel this is the culprit… if you could please help in identifying I would greatly appreciate it
Signature: crystal

Hanging Thief
Hanging Thief

Dear Crystal,
This is a predatory Robber Fly in the genus
Diogmites, a group known as Hanging Thieves because they frequently hang by one leg while eating.  Hanging Thieves are not aggressive toward humans, but they are capable of biting if they are carelessly handled, but that would have required your son catching one and getting bitten.  We do not believe a Hanging Thief is responsible for the stings your son received.

Letter 36 – Hanging Thief


Subject: What type of insect
Location: Southern-Central Illinois
July 11, 2017 5:05 pm
Saw this outside the window. At first thought it was a wasp but then it landed and when I looked at it more closely it resembled a mosquito. What type of insect is this?
Signature: J. Fortado

Hanging Thief

Dear J. Fortado,
This distinctive looking Robber Fly is a Hanging Thief in the genus
Diogmites.  Those long legs are used to capture prey.  These are predatory hunters that take their prey on the wing, and they often eat while hanging from one leg, hence the common name Hanging Thief.

Hanging Thief

Letter 37 – Hanging Thief


Subject: What is this in my house?
Location: Columbus Indiana
July 15, 2017 10:01 am
I found this on my cup in the kitchen. Took it out side and blew it off the cup. The next second the door was open it flew right back in. Very long legs with spikes hairs in the lower part and flies very lazily dipping as it flies around.
Signature: Thank you, T

Hanging Thief

Dear T,
This predatory Robber Fly in the genus
Diogmites uses its long legs to capture prey on the wing.  It eats, often dangling from one leg, which led to the common name Hanging Thief.

Letter 38 – Hanging Thief


Subject: Identify insect
Location: Front Royal, Virginia
July 25, 2017 5:33 pm
Respectfully request an identification of this insect.
Thank you in advance!
Signature: Jean

Hanging Thief

Dear Jean,
This Robber Fly is known as a Hanging Thief because it dangles from one leg while eating prey captured on the wing.

Letter 39 – Hanging Thief


Subject: What is this?
Location: Media, PA
July 30, 2017 6:00 pm
I have never seen this type of bug before! It stood really still for a very long time, even as I was taking it’s picture, and then it flew away, like a helicopter!
Signature: Curious

Hanging Thief

Dear Curious,
This impressive, predatory Robber Fly is known as a Hanging Thief.

Letter 40 – Hanging Thief


Subject: Wasp killing mosquito looking bug
Location: Illinois
August 4, 2017 7:26 am
I have been seeing these is my area, never seen this before. One day I came out to the garage and noticed this bug flying around with a wasp in is legs
Signature: Miller

Hanging Thief

Dear Miller,
This is a Hanging Thief, a Robber Fly in the genus Diogmites.  The common name Hanging Thief is appropriate since they tend to feed on their prey, often large stinging insects caught on the wing, by dangling from one leg.

Letter 41 – Hanging Thief


Subject: Found weird bug
Location: Decatur, Georgia
August 6, 2017 5:39 pm
Hey bug man, some coworkers found this little guy today and helped him outside the restaurant. Can you ID our mystery guest?
Signature: Richard

Hanging Thief

Dear Richard,
This is a predatory Robber Fly known as a Hanging Thief.  Because of the assistance you provided by returning this Hanging Thief to the outdoors, we are tagging this posting with the Bug Humanitarian Award.

Letter 42 – Hanging Thief


Subject:  Big red mosquito bug
Geographic location of the bug:  Tyler, TX
Date: 06/28/2018
Time: 11:02 AM EDT
Your letter to the bugman:  I found this in my house. We have the Saharan Dust (a rare phenomenon hitting East Texas right now.) I’m wondering if it is some sort of African bug that made its way to East Texas. It mad a lot of noise when it was flying.
How you want your letter signed:  Emily Ingram

Hanging Thief

Dear Emily,
This is a Hanging Thief, a species of Robber Fly in the genus
Diogmites, and they are native to North America, so it did not cross the Atlantic ocean from Africa to enter your home.  Like other Robber Flies, Hanging Thieves are beneficial predators that capture flying insects which they feed upon by hanging, often from a single leg, hence the common name Hanging Thief.  We hope you have a catch and release policy for beneficial insects that have accidentally wandered into your home.

Letter 43 – Hanging Thief


Subject:  What Is this?
Geographic location of the bug:  Southern Illinois
Date: 07/15/2018
Time: 01:40 AM EDT
Your letter to the bugman:  Never seen this before in this area… what is this critter?
How you want your letter signed:  Curious

Hanging Thief

Dear Curious,
This is a predatory Robber Fly in the genus
Diogmites, commonly called a Hanging Thief because the insect often hangs from one leg while consuming prey.

Letter 44 – Hanging Thief


Subject:  Insect picture to identify…
Geographic location of the bug:  Ohio
Date: 07/29/2018
Time: 12:40 AM EDT
Your letter to the bugman:  What is it?  Front and side view images attached. Interesting picture, but we don’t know what it is.  July in Ohio.  The deck screw in the picture for reference of size is a #2 Phillips exterior deck screw from Lowe’s.
How you want your letter signed:  Greg

Hanging Thief

Dear Greg,
This magnificent predator is a predatory Robber Fly in the genus
Diogmites, commonly called a Hanging Thief, because after catching its prey, often large stinging insects like Wasps, while flying, it will frequently hang from one leg while dining.

Hanging Thief

Letter 45 – Hanging Thief


Subject:  Bee/Fly/Wasp?
Geographic location of the bug:  Eastern Pennsylvania
Date: 08/10/2018
Time: 09:19 PM EDT
Your letter to the bugman:  I saw this creature in the meadow at Bowman’s Hill Wildflower Preserve in New Hope, PA. It was about 1 inch long.
How you want your letter signed:  Susan

Hanging Thief

Dear Susan,
This predatory Robber Fly in the genus
Diogmites is commonly called a Hanging Thief because often, after catching large insects on the wing, it hangs from one leg to feed.

Letter 46 – Hanging Thief


Subject:  What is this bug!?
Geographic location of the bug:  Glen mills, pa
Date: 08/12/2018
Time: 10:02 PM EDT
Your letter to the bugman:  What it this bug?
How you want your letter signed:  Katie

Hanging Thief Carnage

Dear Katie,
This magnificent predator is a Hanging Thief, a Robber Fly in the genus
Diogmites, and they are not aggressive towards humans, but we suspect a bite might occur if a person tried to catch one with bare hands.  The Hanging Thief captures large flying insects, often on the wing, and then the Hanging Thief hangs from one leg to feed.   The prey are frequently Wasps as images here and here in our archives illustrate.  In our opinion, your image documents what we consider to be Unnecessary Carnage, and we hope any future encounters you have with a Hanging Thief will end differently now that you have learned a bit about this amazing creature. 

Letter 47 – Hanging Thief


Subject:  Don’t know what this bug is
Geographic location of the bug:  Central Florida
Date: 06/19/2019
Time: 12:32 PM EDT
Your letter to the bugman:  Just really curious as to what this bug is. Couldn’t find anything online
How you want your letter signed:  Ty

Hanging Thief

Dear Ty,
This is a Robber Fly in the genus
Diogmites, commonly called a Hanging Thief because this predator often hangs from one leg while eating its prey.

Letter 48 – Hanging Thief


Subject:  Stonefly?
Geographic location of the bug:  Northern Virginia
Date: 07/23/2019
Time: 08:23 PM EDT
Your letter to the bugman:  I spotted this insect a couple days ago when it landed on some dill flowers in my garden in northern Virginia. I thought it might be a type of stonefly, but the eyes seem off. Any help identifying this fella would be greatly appreciated! Thanks!
How you want your letter signed:  Danny

Hanging Thief

Dear Danny,
This Robber Fly is a Hanging Thief in the genus
Diogmites.  Hanging Thieves get their common name from their habit of hanging from one leg while eating their prey.

Letter 49 – Hanging Thief


Subject:  hanging-thief in Western MA?
Geographic location of the bug:  Northampton, MA
Date: 07/25/2019
Time: 10:25 AM EDT
Your letter to the bugman:  Hi! I saw this bug in a parking lot near my house and thought it was a crane fly until it settled down and I got a good look at it. This is the best photo I could get before it flew off. (It’s hard to tell in this lighting but its eyes were green.) Doing some image searches has left me pretty sure it’s some kind of hanging-thief robber fly. Anyway I’ve never seen one of these before and I thought it was neat!
How you want your letter signed:  Matthew D.

Hanging Thief

Dear Matthew D.,
We agree with your identification of this Hanging Thief, a Robber Fly in the genus Diogmites.  Your subject line appears to question if their range includes Maryland and according to BugGuide data, they are found over much of eastern North America.  We are not sure if your research produced the etymology of the common name which refers to the Hanging Thieves’ habit of eating while hanging from one leg.

Letter 50 – Hanging Thief


Subject:  Pic of hanging thief
Geographic location of the bug:  Beaumont , TX
Date: 08/07/2021
Time: 12:43 PM EDT
Your letter to the bugman:  Here is the pic of Hanging Thief from Beaumont,TX
How you want your letter signed:  Sara R.

Hanging Thief

Dear Sara,
Thanks so much for sending in your image of a Hanging Thief, a predatory Robber Fly in the genus

Letter 51 – Hanging Thief


Subject:  Hanging Thief
Geographic location of the bug:  Frederick, MD
Date: 08/12/2021
Time: 10:54 AM EDT
Your letter to the bugman:  Hi bugman! Your website helped me identify what my friend called “demon bug from the pit” as a Hanging Thief or robber fly. I wanted to share some photos I was able to get with this chill little specimen
How you want your letter signed:  Layla

Hanging Thief

Dear Layla,
We cannot possibly answer and post every request we receive, and we respond to many more (though by no means all of them) than we are able to post.  While we have recently posted several new Hanging Thief images, your images are exceptional and a wonderful addition to our archives.

Hanging Thief

Letter 52 – Hanging Thief


I”m Stumped, but the picture is awesome!
I can not identify this critter anywhere on the net and I searched your site and if he’s there, I missed him (not hard to do with the hundreds of beautiful insect images you’ve gotten from around the world..nice job). So what is this fellow…do you know? Found in Bella Vista, Arkansas Thanks much,
Dustie Meads

Hi Dustie,
This is a Hanging Thief, a Robber Fly in the genus Diogmites. They often hang by a single leg while feeding on prey they have captured.

Letter 53 – Hanging Thief: But was it the previous biter????


Large, hideous, biting insect
I live in Iowa City, IA, and last summer I was working on a roof top, and felt a sharp pain on my upper back/shoulder. I turned my head to see quite possibly the ugliest insect I’ve ever observed sticking it’s beak-like mouth parts into my skin. I almost fell off of the roof. It then flew very fast, like a wasp, when I swatted at it. I tried to photograph it with my camera phone, as it landed on a gutter close to me, but it flew away before I could take the picture.
A few days ago, while shopping, I saw what I am 99% positive is the same insect lying dead on a window sill inside the store. I managed to retrieve the insect and brought it home to photograph it. I placed a quarter next to it for size comparison.
Though the images I have provided are relatively clear, I will try to describe the insect as well. In basic shape, it resembles a giant mosquito, with large, wasp-like wings. It has large, black eyes, and short, beak-like mouth parts. It’s thorax is short and thick, with long legs which protrude from it, initially, close together, then flair-out after the first joint. The back of it’s thorax has thin black and gold stripes running laterally from it’s head to it’s abdomen. It’s abdomen is long compared to it’s thorax, and has alternating black and gold segments.
Hopefully, you might tell me what this beast is, and whether it really is a blood-feeder. If it is, I imagine it does not normally bite people, as the bite was very painful. If it is not, why did it choose to bite me?
Regards, Matthew L. Great site, BTW!
Eastern Iowa, USA

Hanging Thief
Hanging Thief

Hi Matthew,
The insect in your photo is a Robber Fly known as a Hanging Thief, possibly Diogmites misellus which is pictured alive on BugGuide. Like all Robber Flies, Hanging Thieves are predators, but they are not considered mammalian blood suckers. Hanging Thieves prey on insects, but they would be capable of biting a human. We want to clarify that they do not suck blood from warm blooded creatures, and if your biter was in fact a Hanging Thief, the bite was something of an anomaly. We would be more inclined to think your biter was a Horse Fly or a Deer Fly and not a Hanging Thief.

Hi Daniel,
Thank you very much for your prompt reply.
I did an image search for both of the insects you mentioned in you letter- a Horse Fly, and a Deer Fly- and I am now even more certain that the insect which bit me, and the image of the dead insect I sent to you are both the same insect. What is most vivid in my recollection of the event are the black and gold stripes on the insects thorax, and it’s head. The insect which bit me was only several inches from my eyes, and, when it flew away, it landed on a gutter near me, allowing me to look at it for at least a minute longer.
I now know from both you, and from several articles I’ve read online about the Hanging Thief, that it is NOT a warm blood-feeder, and, as you mentioned, is, rather, a predator of insects. But, yes, it did bite me, as anomalous an event as that may have been. Maybe it just didn’t like me…
I have always been fascinated by insects and other Arthropods- especially spiders. There are various insects and spiders which really seem to bother other people that I have no problem observing- even handling (gently!). At the same time, there are a few which truly inspire phobia-like terror in me. The Hanging Thief is definitely one of those insects. I have trouble even looking at pictures of the creature. It is a relief to know that it is (for the most part!) harmless, and, likely, beneficial in that it might eat insects which really are problematic.
Anyway, thanks again for your help.
Regards, Matthew La Vallee

Letter 54 – Hanging Thief captures Beetle


ID help please
Hi there,
I’ve attached a photo that I took in southeast Arizona this past week, around Sierra Vista. I was chasing after what I thought was a Tarantula Hawk and saw it land. As I approached the “bug” I saw that it had been captured by a mystery insect. What captured my target? Thanks in advance for your help, and please keep up the good work. I love using your site as a resource for identifying mystery insects.
BJ Stacey
Fins to fur, fangs to feathers: capturing wildlife through a lens.
Check out my web site: http://www.finatic-photography.com/

Hi BJ,
The predator in your photo is a Robber Fly known as a Hanging Thief in the genus Diogmites. The prey is not a Tarantula Hawk, but some species of beetle. The angle of view makes identification a bit difficult.

Letter 55 – Hanging Thief consumes Honey Bee


Robber Fly
Location:  Mayfield, KY
August 8, 2010 2:13 pm
I know I have identified my bug as a robber fly, but it is not the red footed one chosen for the month of August. I have a set of pictures I’d like to share of the robber fly I found on the bush near my house. In the second photo, I noticed a lot of tiny life. There is some kind of larvae near his one foot where he is hanging on the plant. There are oleander aphids visible also. I thought the pictures showed a lot of detail on the robber fly. He looks positively wicked!
Hope you enjoy them.
Janet Fox

Hanging Thief devours Honey Bee

Hi Janet,
This magnificent Robber Fly is a Hanging Thief in the genus
Diogmites, and they are called Hanging Thieves because of their habit of hanging, often from a single leg, while consuming their prey.  We found a photo on BugGuide that matches your specimen, but it is not identified to the species level.  We hope our continued searching will provide a species name for your formidable predator.  We thought that the abdominal markings might be an identifying feature, but browsing through the Diogmites species on BugGuide revealed too many possibilities that look similar for us to attempt a species classification.

Hanging Thief

Ed. Note: August 9, 2010
It is really impossible for our small staff to respond to all queries, and we were searching older letters for something, and we came across this email from Janet prior to the email above.  We would like to remind our readership that if you do not get a response after a week, please resubmit your request with all relevant information and please reattach the image.  DO NOT just send an email inquiring if we got your previous email because then we need to hunt through all unanswered mail.  We apologize for our limitations.

Janet’s Original Request
Strange bug
Location:  Mayfield, KY
July 31, 2010 8:27 pm
I have recently started on some nature photography. We have a bush next to our driveway that has a vine growing on it. I have found that the small white flowers on the vine is a host for many bugs. I was out there the other day and saw a very strange looking bug. It looked like a mutation of a dragonfly and a mosquito. I got a couple pictures of it, then focused on something else. Next time I looked for it, it was higher up the bush and had caught a honey bee. I watched as he stuck his needle nose into the neck area several times. Then he turned the bee around and stuck him in the hind end. Then he turned the bee around a couple more times, then stuck his straw nose into the back end to (I assume) drink his insides. I have looked up predatory insects and can not find this particular bug. Can you tell me what it is?
Sincerely, Janet Fox

Letter 56 – Hanging Thief dead in Alabama


What killed the Hanging Thief???
What killed the Hanging Thief???

Subject: large Mosquioto like thing
Location: Mobile Bay, Mobile, AL
October 10, 2014 10:59 am
Do you have any idea what this guy is? I would hate for it to bite me.
Signature: tonyh

Hi Tonyh,
This is a predatory Robber Fly in the genus
Diogmites, and members of the genus are commonly called Hanging Thieves.  We personally think that Hanging Thieves look much better living than dead.  Hanging Thieves are adept predators that take prey on the wing, and they often feed on large stinging insects like wasps.  Though we would not discount the possibility of being bitten by a Hanging Thief, we have never received any reports of such a bite and from all we have read, Hanging Thieves are not interested in biting humans.  Because it appears that this Hanging Thief has met with an unnatural end at human hands, we are tagging this posting as Unnecessary Carnage and we hope that should you encounter a Hanging Thief again in the future, that it be allowed to fly off to live a full life preying on other flying insects.

Thank you for the reply.  This guy managed to get into the bar at the local yacht club and a frightened member read a page of the local news paper to him.  Too bad since he is a predator of the bugs that pester us the most down on the water.  I will post the info from below to the yacht club web site in hopes of educating the membership and saving the next hanging Thief we encounter.
Thank you again for the info.
Tony Hines.
here is a link to the post on FB.  We will try to do better next time:

Letter 57 – Hanging Thief eating its prey


Subject: Diogmites salutans (I think)
Location: Ocala, FL
August 2, 2013 10:53 am
I got lucky today and this guy landed on the fence right by me to devour his waspish meal. I believe he is a Diogmites salutans. I thought you might enjoy the photo, it was great to get to watch this strange creature. We are in Ocala, Florida and I get a lot of wasps feeding on my Spanish Needles but this is only the second time I’ve seen a Robber Fly.
Signature: Jenifer in Ocala

Hanging Thief eats its prey
Hanging Thief eats its prey

Dear Jenifer,
Thanks to your photo, it is easy to see how Hanging Thieves in the genus
Diogmites get their common name.  While we cannot confirm the species, you have correctly identified the distinctive genus for this Robber Fly.

Letter 58 – Hanging Thief Eats Bee


Hanging Thief Robberfly with Prey
Location: Cheney Kansas
September 23, 2011 4:09 pm
I’ve been trying to get a photo of this bug for about three weeks…It is normally very evasive and won’t land anywhere near my camera.
Today it landed in front of me and let me get a photo of it.
A few minutes later it caught a bee and hung from a small redbud tree ,not only letting me take photos but also touching it get a better pic.
From looking at a Bug site it appears to be a Hanging Thief Robberfly.
Signature: Chris Harris

Hanging Thief and Prey

Hi Chris,
Thanks so much for sending us your wonderful photos of a Hanging Thief with its prey.  Though it is a member of the genus
Diogmites, we are uncertain of the species.

Hanging Thief

Letter 59 – Hanging Thief eats Honey Bee


Subject: Assassin bug?
Location: Beavercreek, OH
August 24, 2015 3:18 am
This bug landed at our table at our local pool. It was carrying a bee & sat there for a few minutes with it’s stinger in the bees head feeding on it.
Signature: Kerry

Hanging Thief eats Robber Fly
Hanging Thief eats Robber Fly

Dear Kerry,
This is not an Assassin Bug.  It is a Robber Fly in the genus
Diogmites, a group known as the Hanging Thieves because they often hang from one leg while feeding.  They take prey on the wing, and this unfortunate Honey Bee stood no chance against such a formidable predator.  While Hanging Thieves and other Robber Flies are considered beneficial predators, they do not distinguish between eating beneficial pollinators and agricultural nuisance insects.  The mouth of the Hanging Thief is adapted to pierce and suck fluids from the body of the prey.  Hanging Thieves do not sting.

Letter 60 – Hanging Thief eats Yellow Jacket


hanging thief
I think you had a picture of one of these in your fly section not hanging. I wasn’t sure from the picture but when you called it a hanging thief I knew right away. Here’s one hanging and eating.

Hi Bill,
Wow!!! What an awesome photo. That Hanging Thief seems to be enjoying the Yellow Jacket it captured. Thanks for sending such an iconic image our way.

Letter 61 – Hanging Thief from Canada


Subject:  Insectes à identifier
Geographic location of the bug:  Varennes,Québec,Canada
Date: 08/08/2021
Time: 07:54 PM EDT
Your letter to the bugman:  Bonjour, j’aimerais identifier cet insecte qui est dans mon gazon.
How you want your letter signed:  Louise

Translation: Hello, I would like to identify this insect that is in my lawn.

Hanging Thief

Dear Louise,
This is a predatory Robber Fly in the genus Diogmites, whose members are called Hanging Thieves.  Normally we do not attempt species identifications on Hanging Thieves, but your individual has a more robust body and some distinctive markings, and be believe based on this BugGuide image that it is
Diogmites basalis.


Letter 62 – Hanging Thief is Marathon Traveler


Can you identify this bug?
Hope you can help as this bug has "attacked" two different people – one in Georgia and one in Kentucky. Thanks.
Nebby McMahon

Hi Nebby,
Wow, that Hanging Thief, a type of Robber Fly, has really chocked up the mileage if it traveled between Georgia and Kentucky.

Letter 63 – Hanging Thief rides bus in Brooklyn


Subject:  Bug on the bus
Geographic location of the bug:  Brooklyn, NY
Date: 08/11/2021
Time: 04:20 PM EDT
Your letter to the bugman:  We saw this winged insect on our bus today, we would love to know what it is! Have not seen before in our neighborhood. The insect was about 1” -1.25” in length. And it is hanging out on the bus still, going to Canarsie!
How you want your letter signed:  B13 bus rider

Hanging Thief

Dear B13 bus rider,
This is a Hanging Thief, a predatory Robber Fly in the genus
Diogmites. They are called Hanging Thieves because they often hang from one leg while feeding on prey.

Hanging Thief
Wow! Thank you so much for the ID! Very cool. My kids and I were coming up with all sorts of terrifying and fantastic possibilities, and this commuting insect now features prominently in our imaginary storytellings. Wonder where the Hanging Thief is now, and if it has found any prey aboard the bus?
Thanks again! We love your site!
The B13 Bus Riders 🙂

Letter 64 – Multi-Link Food Chain: Spider eats Hanging Thief eats Yellow Jacket


Subject: what kind of bug is this?
Location: Newark, DE in the United States
August 5, 2014 11:46 am
My kids have been telling me about this crazy looking bug that has been eating bees in our back yard. But I have never seen one personally until today my son pointed one out with a bee captured in its mouth while both are captured in a spider Web! If you could identify this so I can explain to them I would greatly appreciate it alot. Plus for my knowledge also. Thank you greatly and Good bless.
Signature: Pyle Boys

Spider eats Hanging Thief eats Yellowjacket
Spider eats Hanging Thief eats Yellowjacket

Dear Pyle Boys,
We need to begin by telling you we love your documentation of a multi-link Food Chain.  We only wish your image was sharp enough and detailed enough for us to be able to identify the Spider.  The flying predator is a type of Robber Fly known as a Hanging Thief in the genus
Diogmites.  The Hanging Thief gets its common name because it often hangs from one leg while eating the large winged prey, often bees or wasps, that it captures on the wing.  The prey in question is not a bee, but a Yellowjacket.

Multi-Link Food Chair:  Spider eats Fly eats Wasp
Multi-Link Food Chair: Spider eats Fly eats Wasp

I am gonna attach a few more pics of the spider close up and hopefully this can help. And thank you for clearing up the curiosity for me and my sons! And glad you like the food chain effect my son thought it was cool how life works. Thanks again!

Possibly Common House Spider
Possibly Common House Spider

Thanks for sending the additional images, but unfortunately, the images are not critically sharp and it also appears that the color is decidedly cyan/blue, which makes the subtle coloration on the spider difficult to distinguish.  The Hanging Thief and Yellowjacket were quite obvious, but not so with the spider, which may be a Common House Spider, Parasteatoda tepidariorum.  You can see the resemblance to this individual on Bugguide.


Letter 65 – Probably Hanging Thief


Subject: Wasp?
Location: Northern Virginia
August 13, 2012 7:58 pm
Hello! I found this nasty guy in my house the other day trying to fly through a window. Luckily I found it before my children saw it. I did some searching but couldn’t find anything like it. Is it some sort of wasp? Thanks!
Signature: C.A.

Probably Hanging Thief

Dear C.A.,
This is some species of Robber Fly and we believe it is a Hanging Thief in the genus
Diogmites, however we are unable to find an exact match on BugGuide.  We believe this is closest to the New York Bee Killer, Diogmites basalis, which BugGuide describes as:  “A large reddish brown species, with golden spots on each side of the abdominal segments,” however your specimen appears to lack the golden spots.  Perhaps it is the angle of view.


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14 Comments. Leave new

  • The prey here is the European paper wasp Polistes dominulus

  • Thank you for your assistance. The green eyes threw me off. I have not seen one with green eyes. This is a great website. I have always taken insect macro photos. Now I know where I can send a few. Take care.

    • Your photos are beautiful. Our one request is that when you send images, please confine your submissions to one species per post.

  • I found a few bugs in my daughters room. I wanted to know how to send a pic in the hope someone can tell me what they are?

  • Reminds me of an observation made by Jean-Henri Fabre, the French entomologist. Fabre was watching a parasitic wasp carrying off a honey bee, which would serve as food for its offspring. As the wasp flew past Fabre, it was snatched out of the air by a praying mantis. The mantis began to eat the wasp, which not only kept hold of the bee but continued to nibble the pollen that adhered to the bee’s legs—Fabre had previously noticed that this kind of wasp, though not predatory as an adult, has the habit of helping itself to the pollen it found on its paralyzed victims. Nature is spooky.

    • Thanks for the awesome comment. We have Fabre’s Book of Insects, and your comment is inspiring us to reread his fascinating observations.

  • I don’t know if this particular bit is included in Fabre’s Book of Insects, which, as I understand, is a retelling rather than a straight translation of some parts Fabre’s big work, Souvenirs Entomologiques. I’ve heard that the Book of Insects is faithful to the spirit of Fabre’s books, but I’ve never read it myself. When I was a kid, the local library had a whole series of Fabre books with titles like Life of the Fly, Life of the Spider, and so forth. I read every one of these books I could find. I can’t remember in which one I encountered the story about the wasp: I just hope I’m recalling it accurately since I’m relying on memory. It did make a powerful impression, though.

    • Thanks for the clarification. If we have the time to read the volume in our possession, we will let you know if we encounter that particular observation.

  • We have one in the restroom now. Washington mo. I have also seen them in Carlyle il.

  • In fact, you may have wasps nearby. They are predatory towards many flying insects, even ones larger than themselves. I’ve seen them go after wasps and bees. They don’t always win, but they do try. I’d check the house or the yard for wasps’ nests.

  • Larval robber flies are seldom seen, and are usually found in soil. They are legless and soft-bodied, and some are fairly large. A robber fly larva is pictured here at Florida’s Featured Creatures page. Larval and adult robber flies are predators of other insects. The adults are famous for their ability to capture prey in the air. In fact, robber flies will often catch insects that are larger than themselves, such as bumble bees.

  • Brittany Carnley
    July 18, 2017 4:00 pm

    I just had one come up and land on my phone while it was in my hand. I’m in Oak Grove, Kentucky. It let me turn my phone around and look at it without flying away. Pretty cool.

  • We have had these where I work out in Illinois

  • We have a pic of one in Beaumont, TX .


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