Robber Fly Fun Facts: Discover the Thrilling World of These Predators

The fascinating world of insects is full of unique and diverse creatures, one of which is the robber fly. Known for their fierceness and adaptability, robber flies are intriguing predators to learn about. There are roughly 7,000 species worldwide, with about 1,000 native to North America source.

These voracious hunters are easily recognized by their signature characteristics, including their two wings, large compound eyes, and a beak-like proboscis. Robber flies are often found in open habitats and are most active during the daytime, making them interesting subjects for insect enthusiasts source.

General Overview of Robber Flies

Robber flies, belonging to the family Asilidae within the order Diptera, are fascinating insects with a few distinctive characteristics. They are medium-sized to large flies, covered in bristles or hair, giving them a somewhat fierce appearance. These predators are known for their voracious appetites and ability to feed on a variety of other arthropods.

Their size ranges from 0.2 to 2 inches, and their coloration varies greatly among the roughly 1,000 species found in North America. Some are grey and black, while others mimic the appearance of bumblebees, wasps, or other insects. Two examples of their habitat range include warm tropical/sub-tropical settings and cool forest glades.

Key features of Robber Flies:

• Medium-sized to large insects
• Bristly or hairy appearance
• Over 1,000 species in North America
• 0.2 to 2 inches in size
• Diverse coloration
• Predatory diet of other arthropods

As predators, robber flies attack various prey such as wasps, bees, dragonflies, grasshoppers, other flies, and even some spiders. They have a unique way of capturing their victims by pouncing on them mid-air, and immobilizing them with venomous saliva.

In terms of benefits, robber flies help maintain a healthy balance between insect populations in different habitats. They contribute to pest control by preying on insects that may cause harm to plants, animals, or humans.

Pros of Robber Flies:

• Maintain balance in insect populations
• Contribute to natural pest control

Cons of Robber Flies:

• Can prey on beneficial insects

Overall, robber flies are intriguing creatures with their predatory behavior, wide array of appearances, and vital role in ecosystem balance. While they may look intimidating, they play an essential part in controlling insect populations and contributing to pest management.

Physical Appearance and Anatomy

Robber flies have a fierce appearance, making them stand out among other insects. Their unique features include:

• Large, widely-spaced compound eyes
• One pair of wings
• Prominent spikes on their legs
• Stout hairs on the body
• A sharp, pointy proboscis for feeding

Coloration varies among the 7,000 species found worldwide, with many exhibiting grey and black tones, while others mimic the bright colors of their prey, such as bees. Some robber flies even have yellow, white, or a combination of hues in their color patterns.

An interesting feature of robber flies is their mystax, a beard-like structure on the face. This mystax serves as protective shield, helping to prevent injury during their predatory activities.

Comparison Table:

In conclusion, robber flies are fascinating creatures with distinct physical features that set them apart from other insects, particularly due to their large compound eyes, single pair of wings, and mystax.

Behavior and Habitat

Robber flies, also known as assassin flies, are fascinating predators in the insect world. They display exceptional hunting skills.

These predators often target other insects like grasshoppers, wasps, and ants as their prey. They are also known to attack dragonflies.

Robber flies are experts in ambush, catching their prey mid-flight. They inject venom to paralyze their prey.

These insects prefer hot and arid places, such as grasslands, deserts, and forests. They thrive in open spaces where they can spot potential prey.

They are often solitary animals. They patiently perch and observe before going for the kill.

An adult robber fly can grow up to 3 in (8 cm) in length. This makes them considerably larger than most other flies.

In summary:

• Predators: Grasshoppers, wasps, ants, dragonflies, etc.
• Habitat: Grasslands, deserts, forests
• Size: Up to 3 in (8 cm)
• Behavior: Solitary, ambush predators

Their unique characteristics make them efficient predators and an interesting subject of study.

Life Cycle and Reproduction

Robber flies are known for their predatory skills and fascinating life cycle. Their life cycle begins with the female laying eggs in soil, or on plants. They possess an ovipositor, which helps them insert eggs in suitable locations.

The eggs eventually hatch into larvae. These larvae are also predators, feeding on other insects or their eggs. While larval stages may vary among species, they typically live in the soil or within decomposing plant material. They are equipped with unique mouthparts for consuming their prey.

As the larvae grow, they undergo several molts before they’re ready to pupate. During pupation, they form a protective case and undergo metamorphosis to become adults.

Adult robber flies showcase strong predatory skills, making them successful hunters. They have large, widely-spaced compound eyes to spot prey easily. The flies are also characterized by their bearded faces, prominent beak, and spiny legs.

Robber flies display a fascinating mating behavior. Males and females engage in mid-air mating, sometimes using prey as a nuptial gift. This ensures successful mating while also demonstrating the male’s hunting abilities.

Here are some key robber fly characteristics in bullet points:

• Both larvae and adults are predators
• Female robber flies have an ovipositor for egg-laying
• Larvae typically live in soil or decomposing plants
• Adult robber flies have large compound eyes and bearded faces

In North America, there are over 1,000 species of robber flies. They vary in size, colors, and shapes, but all are fierce predators. For example, some robber flies are known to prey on larger insects like bumblebees. Their hunting ability, combined with their fascinating life cycle, make them a unique group of insects.

Feeding and Hunting Strategies

Robber flies, or assassin flies, belong to the Diptera order and are known for their predatory nature and fast flight. A fascinating aspect of them is their wide diet, which includes various insects like beetles, butterflies, other flies, moths, crickets, and even spiders. They are native to different regions and can be quite beneficial for controlling insect populations.

These flies excel at hunting, capturing their prey mid-air. They use their powerful legs, adorned with prominent spikes, and their large, widely-spaced compound eyes for tracking and capturing flying insects. Their distinctive proboscis, fashioned into a sharp tube or beak, delivers a painful bite and is used to inject an enzyme that paralyzes and liquefies the insides of their prey, making it easier to consume.

Some of the unique features of robber flies include:

• Fast flight
• Predatory nature
• Painful bite
• Sharp tube-like proboscis
• Large compound eyes

Their hunting strategies vary among the different types and species, such as the Choerades fimbriata, which is known for preying on houseflies and other airborne insects, including the Phoridae family. They are oval-shaped and often confused with biting flies due to their size and buzzing sound while flying.

Here is a comparison table to highlight key differences between robber flies and biting flies:

In summary, robber flies showcase a diverse diet and clever hunting strategies, acting as beneficial predators in their ecosystems. Their unique features and predatory nature set them apart from other flying insects, including biting flies.

Distribution and Threat Status

Robber flies are native to North America and known for being efficient predators in the insect world. They belong to a diverse group of species with over 7,000 species identified.

• Native: North America, France, India, and other countries
• Insects: Predatory flies
• Species: Over 7,000 species worldwide

These fascinating insects can be found in various environments, except for Antarctica. Their fast flight ability allows them to efficiently catch their prey.

Comparison of Robber Flies and other Predatory Flies

Robber flies are generally able to maintain a stable population. While some species might face specific threats, they are usually considered of least concern regarding their conservation status.

However, it is essential to monitor insect populations and protect endangered species in all ecosystems.

Significance and Benefits to Humans

Robber flies are beneficial insects, especially for gardeners. These fierce predators help control populations of harmful insects in gardens and horticultural landscapes.

Characteristics of Robber Flies:

• Large size
• Loud buzz when flying
• Two wings
• Prominent spikes on legs
• Stout hairs on body
• Prominent proboscis

Gardeners appreciate the giant robber fly for their role in pest control. Their aggression and dominance in preying on other insects translate to fewer pests harming plants.

Even the smallest robber flies, measuring around 0.07 in (2 mm), play a role in controlling pests in various environments.

Robber flies use body movement and courtship displays to communicate, which can be seen during copulation, making them fascinating to observe. For example, in Thailand, some robber fly species engage in complex mating rituals.

In summary:

• Robber flies benefit humans by controlling harmful insects in gardens and horticultural landscapes
• They range in size and display interesting behaviors, making them intriguing creatures to study

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 – Two Flies Mimic Bumble Bees: Bee-Like Robber Fly and Still Unknown Flower Fly

Request: Bumble Bee Mimics
July 16, 2010
Location:  North Middle Tennessee
Hi Daniel,
Here are a couple of bee mimics the first two I believe is a ”Robber Fly” I was going to include a bumblebee for comparison, but it just didn’t look right. After doing a bit of searching online I now belive it to be a ”Syrphid Fly” I now wonder just how many of the things buzzing around the yard are actually ”Bumblebees” (Will just let the critters figure it out for themselves) Thank You and have a wonderful day.
Richard

Hi Richard,
Your photo of the Bee-Like Robber Fly in the genus Laphria is excellent for the genus identification.  It shows the thicker antennae of the genus Laprhia which differ from the antennae that are thin and threadlike at the final segment in the genus Mallophora.  We believe this may be Laphria thoracica, based on the photos and the range indicated on BugGuide. I agree that the second fly is a Syrphid Fly in the family Syrphidae.  I got a bit dizzy going through all the possibilities on BugGuide, but I believe your specimen is probably in the subfamily Eristalinae based on images posted to BugGuide.  Characteristics of your specimen like the coloration, smooth black abdomen, and fuzzy yellow thorax are quite distinctive and should make identification relatively easy, but we remain without luck in that arena.

Letter 2 – Bumble Bee Mimic Robber Fly

Subject: bee fly??
Location: Boxford, MA
June 11, 2013 7:15 pm
As I was hiking in a woodland field surrounded by flowers, I came across this guy. I thought it was a bumblebee but then I saw it’s big fly-like eyes.
I would love to know what it is.
Thanks!
Signature: Roberta

Dear Roberta,
This is a Robber Fly in the family Asilidae and there are many genera with species that resemble Bumble Bees, like your individual.  We believe this might be Laphria flavicollis based on this image posted to BugGuide.  According to BugGuide,  “adults predaceous on flying insects, including bees and other robber flies” and these Bee-Like Robber Flies were originally classified as “Bombomima Enderlein.”

Letter 3 – Bee-Like Robber Fly

Unknown Insect
Location: SW Florida
March 11, 2011 7:27 pm
Haven’t seen this one before. Found in a local park. Landed only on leaves & always faced me when moving from leaf to leaf. About 2 inches long. Also flies. Head swivels like Dragonflies does. I’ve been taking nature photos for 20 years & this bug is a new one for me & I cannot find it in any of my critter I.D. books. Hope you can help, thnak you.
Signature: Susan

Hi Susan,
This is a Robber Fly in the family Asilidae, but we are having problems with a more specific identification.  We believe it is either in either the genus Mallophora or the genus Laphria, both of which mimic bees.  These predatory Robber Flies are fierce hunters and they prey upon bees, wasps and other large flying insects which they attack on the wing.  We are favoring Laphria, because it appears that the antennae are thicker, though the angle of your photograph makes that feature difficult to verify.  There are numerous species in the genus Laphria, and we are having problems identifying all the features your specimen possesses and matching them to a specific species.  The combination of yellow beard, yellow thorax, yellow markings on abdomen, and yellow hairs on the legs should be distinguishing features, and we cannot seem to find a match on BugGuide.  We are going to try to contact a Robber Fly expert, Dr. Robert Cannings, to see if he is able to provide a species identification.

Hi Daniel:
It’s good to hear from you.
The robber fly is definitely a Laphria. There are a number of species in Florida, and I’m not familiar enough with them to be able to make a reasonable guess at this one’s identity. It’s a nice photo, but I can’t see the sides of the thorax or the abdominal colour pattern well enough to run it through a key.  You could try Eric Fisher who knows much more about southern US species than I do.
Sorry I can’t be of more help.
Regards,
Rob

Letter 4 – Bee Killer: Mallophora fautrix

Subject: Two days in a row I came across these in the morning. Sacken’s Bee Hunterr
Location: Hemet Ca.
July 18, 2014 12:53 pm
I see that these kill our honey bees, I have found tow on the truck on two different days. I left them alone becasue I was not sure what they were. Now that I know, I want to kill them to protect our honey bees. your thoughts?
Signature: Lynn in So Cal

Hi Lynn,
Your mistaking this Bee Killer, Mallophora fautrix, for Sacken’s Bee Hunter is understandable, but taking a closer look at the images posted to BugGuide and comparing them to images of Bee Killers in our archive will reveal some differences.  Sacken’s Bee Hunter has a yellow thorax and black abdomen with yellow tip, while your individual has a black thorax and yellow abdomen.  The antennae are also more thin and hairlike, and according to BugGuide, individuals in the genus Mallophora have :  “antennae with a very thin terminal final segment, whereas Laphria has thick antennae.”  We would urge you not to kill the Robber Flies as their predation is not the greatest problem faced by Honey Bees, and while the Robber Flies will prey on Honey Bees, they also feed on a variety of other winged insects.  Images in our archives show them preying on wasps.

Thank you so much for this information!. I have not nor will I kill these bee killers. I know everything has a place in the food chain and now that I know they do not just prey on our honey bees I will leave them alone, I found another this morning, I find it strange  to find one in the last 3 days. I need to read up on them to see if they have hives or nest?
Thanks again!!!
Lynn

Robber Flies are solitary hunters that do not have hives nor nests.

Letter 5 – Beewolf

Wasps in a big network of tunnels? Near a bumblebee nest?
Dear Bugman,
My husband and I just moved into our first home. Much to my surprise I noted that there were over 20 holes dug into the dry dirt of our yard around the deck. After a bit of spying I noticed that small insects were flying into them. The holes are about the width of a standard pencil, sometimes smaller. They are reopened quickly after filled with dirt. We have a number of abandoned quarter sized holes in our yard, and while watching the mystery bug I noticed that two of those appear to be entrances to a bumblebee nest which we would like to leave undisturbed as they are bee-coming rare (sorry, couldn’t help it). The closest thing I have found searching the web is a Mason Wasp or Potter Wasp, but I’m not certain by any means, and nowhere can I find information about whether they sting, or return to the same nest year after year. We would like to till and plant in the fall after the bees abandon their nest, but if there is a huge area of wasps that may not be wise. Attached is a picture of our mystery bug, a picture of him digging, a picture of the affected area, a picture of the burrows, and a picture of the nearby bee nest outlet. Thank you so much for your time and expertise.
Panicked Homeowner,
Amy White

Hi Amy,
We are happy you did not sign your letter “Desperate Housewife” and you really have no need to fear. The wasps and bees are unrelated and as you have determined a course of action for the bees, we will just address the Sand Wasps. We cannot identify the species, but your Sand Wasps appear to be in the Tribe Nyssonini, based on images posted to BugGuide. Though Sand Wasps are solitary, they do tend to nest in proximity to one another, in a communal situation rather like a housing development. They are not aggressive, and will not attack. We will contact Eric Eaton to see if he can add anything or refute our reply in any way.

Update: (07/25/2008)
Hi:
The “sand wasps” are known as “beewolves” in the genus Philanthus. The females are solitary, each digging her own nest burrow. These wasps hunt and paralyze small bees (mostly “sweat bees” in the family Halictidae) which they stock in the nest as future food for their offpsring.
Eric

Letter 6 – Bee Killer

Is it a fly? Bee? Beetle?
Location: NE Los Angeles
July 27, 2011 2:27 pm
My daugher and I were outside in our Eagle Rock, California backyard and this delightful bug flew past and decided to land on my shoe. After I gave my shoe a gentle shake, it flew over to a blade of grass. We are perplexed as to what exactly it is!
Signature: Loving the flying things

Hi Ltft,
Our offices are in nearby Mt Washington.  This is a Robber Fly known as a Bee Killer, Mallophora fautrix.  They are predators that catch large flying insects, including bees and wasps, while on the wing.

Letter 7 – Bee Killer

Subject: Robber Fly
Location: Baldwin Hills in Los Angeles, CA
July 20, 2012 1:12 pm
Hi. Here are the shots of that robber fly I mentioned, taken July 15, 2009. S/he’s just over an inch long.
Signature: Tracy

Hi Tracy,
Though your most recent visitor is a Tachinid Fly rather than a Robber Fly, this impressive specimen from several years ago really is a Robber Fly, more specifically a Bee Killer, Mallophora fautrix.  According to BugGuide, it is the only member of its genus found in California.  Bee Killers are large Robber Flies that attack on the wing Bees, Wasps and other large flying insects.

Letter 8 – Bee Killer

Subject: predatory fly
Location: Cardiff-by-the-Sea, CA
July 26, 2015 4:20 pm
Saw this fly in a neighbor’s dead bamboo. I got a look at it through binoculars, and it reminded me of deer flies I’ve seen in NorCal and So. OR, but those don’t live here, nor do they take other flies as prey. The first photo is a nice clear shot from underneath, and you can see the wings of the prey sticking out. In the, second, rather blurry photo (just could *not* get the camera to focus on anything but those intervening twigs), you can kind-of make out the relative position and size of the two. The predator was an inch (or so) long, and I’ve never knowingly seen another one in my 50+ years in this area.
Signature: Eric Simpson

Dear Eric,
This predator is a Robber Fly, and though the image is not the best for identification purposes, we suspect it is a Bee Killer, Mallophora fautrix, the only member of the genus found in California.  These large Robber Flies are impressive and very adept hunters.

Letter 9 – Bee Killer

Subject: Bee?
Location: Midland, Texas
July 31, 2015 11:16 am
This looks like a bee but the hairy legs and wings look strange.
Signature: TLW

Dear TLW,
This magnificent predatory Robber Fly is a Bee Killer in the genus Mallophora, and we believe we have correctly identified it as Mallophora fautrix by comparing your images to this image on BugGuide.

Letter 10 – Bee Killer

Subject: What’s This!
Location: Inglewood, California (Southern, CA)
August 17, 2016 4:48 pm
Hello!
I was walking from my car to work in Inglewood, CA today, August 17, 2016, and found this guy on my way. I would say he\she was about an inch to an inch and 1/2 long and pretty stout. Could you please help me identify?
P.S. BUGS RULE
Signature: Amanda Paull

Dear Amanda,
This is Mallophora fautrix, the only Bee Killer, a Robber Fly in the genus Mallophora, found in California, though according to BugGuide there are six species found in North America, including the formidable Belzebul Bee-Eater from Texas. 

Letter 11 – Bee Killer

Subject: A Black & White Bee?
Location: West Los Angeles
September 4, 2016 1:27 pm
Hi Bugman,
Found this creature clinging to a milkweed plant early one morning. Can you tell me what it is?
Signature: Jeff Bremer

Dear Jeff,
This is not a Bee, but rather a Bee Killer, one of the Robber Flies in the genus Mallophora.  The only member of the genus currently known from California is Mallophora fautrix, and according to BugGuide, its range is “sw. US (CA-TX-UT) & Mexico.”  Genus characteristics, according to BugGuide, are “Large, fuzzy, bee-mimicking robber flies” and “Predatory on other insects, including large bees, wasps.”  

Letter 12 – Bee Killer and Prey

Bee dining on yellowjacket?
Location:  Los Angeles
October 12, 2010 1:22 am
Dear Bug People,
I had all kinds of activity in the garden this summer, mostly beneficial on the bug front.
This has to be my most interesting bug pic of the season. I’m calling it ”B2B”.
What’s going on here?
Signature:  David Wolfberg

Dear David,
According to BugGuide, the “antennae with a very thin terminal final segment” indicate that this is a Robber Fly in the genus Mallophora, the Bee Killers.  There are two species listed on BugGuide as ranging to in the southwest, M. leschenaulti and M. fautrix, but this looks like neither.  We believe it looks like the Southern Bee Killer, Mallophora orcina, which BugGuide lists as living in the  “Eastern United States: North Carolina (and further north?), west to Ohio, Missouri, south to Florida“, though the BugGuide Data page on the species indicates a sighting in Arizona.  Our money is on the Southern Bee Killer, though if this is a range expansion or a stray is fodder for the experts.

Awesome, Daniel.  We’re in Leimert Park.  Did you see this shot of Mallophora fautrix from the bug guide?  A commenter asserts the orcina won’t be in California (but really one doesn’t know any more):
http://bugguide.net/node/view/129189
I will check through the other shots I took to see if I can get a better view of the top pattern.
Also examining my photo on a larger monitor now, I believe the killer isn’t feeding on a yellow jacket but on my friendly neighborhood european paper wasp.  The wasps have been this gardener’s best friend over the summer.
David

Thanks for the update David.  Your specimen does seem to resemble the Mallophora fautrix that you linked to, but again, since the Southern Bee Killer is reported from Arizona, the Leimert Park neighborhood of Los Angeles is not an impossibility.  We are, after all, a city of immigrants.

Letter 13 – Bee Killer, but what species???

Subject: Possible Bee Killer Robber Fly
Location: Auburndale, FL
September 4, 2013 1:16 pm
Not sure if this is a Southern or Florida Bee Killer, or just another type of Robber Fly. Super pretty, whatever it is.
Signature: Sharon

Hi Sharon,
This is a stunning photo of a stunning Robber Fly.  We agree that it is a Bee Killer in the genus Mallophora, however we are not certain of the species.  Unlike the images of the Southern Bee Killer on BugGuide which have a black tipped abdomen, your individual has a yellow tip on the abdomen.  There is one Bee Killer also from Florida on BugGuide with the identical markings to your Bee Killer, however it is not identified to the species level.

Letter 14 – Bee Killer eats Honey Bee

Subject: Wasp? eating ?
Location: San diego
August 17, 2014 11:06 am
Hello Bugman,
Saw what looks like to be a white and black wasp hanging around the garden today. First time I have seen a wasp like this, it is fairly large, looks like it might be eating a small frog?
Signature: curious

Dear curious,
This predatory Robber Fly is a Bee Killer, Mallophora fautrix, and it appears to be eating a Honey Bee.

Letter 15 – Bee Killer eats Prey

Subject: What’s happening here?
Location: Houston area, Texas
September 28, 2013 1:00 pm
I walked around these bugs in our river birch sapling for 10 minutes, trying to get my camera to focus on the right thing and also to figure out what was going on — if they were mating, or if one was getting eaten.
They were both about an inch and a half long. One appeared solid black with very hairy legs. The other, looking at the photo now, appears to be black and yellow.
Is the black one squeezing the other so hard it’s innards have come out?
They stayed where they were for about 5 minutes until I ventured too close, at which time the black one flew off, carrying the other one with it.
Signature: Jayne

Hi Jayne,
This is a nice photo for our Food Chain tag.  The predator is a Robber Fly, most likely a Bee Killer in the genus Mallophora, possibly a Belzebul Bee Eater.  We cannot identify the prey from your photo, but it does not appear to be a bee or wasp which frequently fall prey to large Robber Flies.

Letter 16 – Bee Killer in California

Location is Hawthorne, CA – Volucella bombylans?
Dear Bugman,
I emailed you a while ago with a blurry photo of something I’d not seen before. Today I was able to get sharp shots of this bug and it’s prey. I’ve attached two of them in hopes that you will be able to tell me if it is a hoverfly. Thanks for your time! I’m in Hawthorne, California – please don’t send me directly to the Trash!!! Sincerely,
Anna Carreon

Hi Anna,
This is a species of Robber Fly known as a Bee Killer. It is Mallophora fautrix, which accoring to BugGuide, is the only species in the genus found in California. We received another photo a few days ago. Putting an unusual scientific name in your subject line was a good way to get our attention.

Hi Daniel,
Thanks for your information. A cousin of mine saw the posting of the Mallophora fautrix posted on your site and emailed me about it (I hadn’t been out to the site since the day before it was posted). What an interesting creature this is! I’d never seen one before, and my mother, who lives .3 miles away, is now in search of one in her back yard. She says she’s never seen one in her 77 years of life and she’s determined to see one in her next 77 years.
Anna

Letter 17 – Bee Killer in Las Vegas

Subject:  Unknown bee
Geographic location of the bug:  Las Vegas NEvada
Date: 08/19/2021
Time: 08:29 PM EDT
Your letter to the bugman:  Could you please help me identify this bee?
How you want your letter signed:  Sincerely, Dr. Merkler

Dear Dr. Merkler,
This is not a Bee, but rather a predatory Robber Fly known as a Bee Killer, Mallophora fautrix.

Daniel,
I think in the back recesses if my mind, I knew this (once upon a time!).  Thank you so much!!
Dr. M

We are so happy we were able to refresh your memory.

Letter 18 – Bee Killer in Ventura

Subject:  Bee-like Fly
Geographic location of the bug:  Ventura County, CA
Date: 08/06/2021
Time: 12:50 PM EDT
Your letter to the bugman:  What is this bug that was sitting on my kitchen counter?
How you want your letter signed:  Kevin the Curious

Dear Kevin the Curious,
Wow, Ventura California is blowing up with insect identification requests this morning.  We just finished posting an image of a “Conspicua” Lady Beetle from Ventura.  This is a Robber Fly, Mallophora fautrix, a member of a genus known as Bee Killers because they often prey on large Bees and Wasps.  This is “The only representative of the genus in California”, according to BugGuide, and it is pictured on Natural History of Orange County.

Letter 19 – Bee Killer Kills Bee

Bee eating another bee
August 6, 2009
We saw a bee catch another bee in midair. It then flew away with it’s prey in mouth only to get eaten by a bird in midair. Food chain in action!
Jonathan Bergado
Santa Fe Springs, CA

Hi Jonathan,
The predator in your photo is not a Bee, but rather a Robber Fly known as a Bee Killer.  It is Mallophora fautrix, the only member of the genus in California according to BugGuide. The prey is a Honey Bee.

Letter 20 – Bee Killer Kills Japanese Beetle

Picture
Hi,
Here is a picture that I cropped of the bug I saw in my garden yesterday. We live just north of Baltimore, MD. It was sucking the juice out of a Japanese beetle.
Thanks,
Andrew

Hi Andrew,
My, oh, my! What a wonderful photo of a Bee Killer, a type of Robber Fly, devouring a Japanese Beetle.

Letter 21 – Bee Killer, but which species???

Subject: Another Southern Bee Killer?
Location: Coryell County, Texas
August 14, 2014 9:55 am
I saw that you had many robber fly inquiries last week. Here is mine. 🙂
You kindly identified a Southern Bee Killer for me several years ago. Is this insect the same? It was hiding in plain sight, holding perfectly still on a young crepe myrtle tree, which is a bee magnet due to its many fragrant clusters of blossoms.
Thank you!
Signature: Ellen

Dear Ellen,
Taking a closer look at your previous submission from 2009, we now believe neither is a Southern Bee Killer, Mallophora orcina, as the individuals pictured on BugGuide all have black-tipped abdomens.  Your individual appears to have a yellow abdomen all the way to the tip, which is why we believe it is a different species in the same genus, Mallophora fautrix.  Compare your images to this individual on BugGuide.  According to BugGuide, it ranges from:  “Texas west to California, southward through Mexico.”  We would really love to get an expert opinion on this identification.

Letter 22 – Bee Killer in Torrance, California

Subject: A Fly Or A Bee?
Location: Torrance, California
July 24, 2014 9:49 am
Dear Bugman,
By the end of June of this year, we found a couple of these insects in our front yard. The bigger one was about one inch long. We live in Torrance, California, and have never seen them before. Could you help us to identify them?
Thanks.
Signature: Daniel.

Dear Daniel,
This Robber Fly in the genus Mallophora goes by the collective general name of Bee Killer.  Your particular Bee Killer is Mallophora fautrix, a species with no specific common name, but according to BugGuide, it is:  “The only one of its genus in California.”  As you can see from the images in our links, Bee Killers prey on large flying insects other than Bees, and it is a rare, top of the insect food chain predator that preys upon adult, stinging wasps.  Though you are not the discoverer of a new species, you can spearhead a campaign to nominate the only Bee Killer in California as the California Bee Killer, even though its range extends beyond our fair state.

Letter 23 – Bee Killer with Prey and Red Footed Cannibalfly

Subject: false bumble bee??
Location: tyler rose garden, texas
July 9, 2012 3:24 pm
found this today at rose garden here at tyler, texas..looks like a bumble bee but it is eating another bee, possibly a real bumble bee..i know bugs pretty well but no idea what this one is..summer..july 9..
Signature: huh??unsure what this means..standard i guess..

Dear huh??,
This Robber Fly is a Bee Killer, Mallophora orcina, which you can verify on bugGuide.  The prey in this photo might be a Honey Bee, but it is difficult to tell for certain.

thanx, i have a photo of a bearded robber fly but the colors on this one totally different….i try to positively identify my photos before posting..again thanx!

Thanks for sending another photo of a Robber Fly.  In our opinion, this is a Red Footed Cannibalfly, Promachus rufipes, one of the Giant Robber Flies.  You can verify that identification on BugGuide.  These large Robber Flies are very impressive and you do grow them big in Texas.

Letter 24 – Bee Killer Assassin Bug from Panama

Subject: Assasin bug ?
Location: Chiriqui Panama
January 11, 2014 10:44 am
I can’t imagine this is an assasin bug with these bright red “flags”. What kind of stealth is that?
Signature: Linda

Hi Linda,
This is not an Assassin Bug.  We believe this is a Leaf Footed Bug or Big Legged Bug in the family Coreidae.  Some tropical species have especially exaggerated leaf-like expansions on the hind tibiae which resemble flags, so these tropical species are commonly called Flag Footed Bugs.  Here is a Flag Footed Bug from Costa Rica and here is a different Flag Footed Bug from Costa Rica.  We believe more tourists visit Costa Rica than any other Central American country, so examples from Costa Rica tend to be most plentiful in our archives.  We have not had any luck matching your image to anything online.  Do you have a more traditional dorsal view as opposed to this artistic “head on” perspective?

Daniel,
Although this is probably not the exact bug since I took these 2/2013, it shows his dorsal and also his proboscis which is why I thought it was an assasin bug, with it folded over as it is. If this isn’t the exact kind of bug, it at least looks identical in terms of coloring and pattern.
Living in Panama is great but you are correct, almost all of my id. help from butterflies, etc. is based on Costa Rica information.
Thanks for your help.

Retraction:  We stand corrected!!!
Hi Linda,
We would like to retract the Flag Bug identification.  We now agree with you that this is most likely an Assassin Bug, possibly a Bee Assassin in the genus Apiomeris.  The angle of the original photo made it appear that the “flags” were on the legs, when in fact they now appear to be on the wings or abdomen.  All True Bugs have mouths designed for piercing and sucking, even the plant feeding species.  We will attempt to make an identification based on the new photos.  We quickly located
Apiomeris vexillarius from Costa Rica on Monga Bay.  There are also photos on Discover Life and Project Noah.  We even have a photo of Apiomeris vexillarius in our own archive.

Sorry that I had forgotten the old photo of the similar bug (whose flags either were not extended or not developed?). It certainly helps to have many angles, plus my photo today didn’t show well since my flash ran out of batteries and it was in a dark wooded area.
Anyway, I loved seeing all of the other great photos and now I can label it correctly.
Thank you once again.
Linda

Are there any Assasin bugs that are dangerous to humans? I know you said they have a painful bite but are the dangerous in any other way?
Thanks,
Linda

Kissing Bugs or Blood Sucking Conenose Bugs in the genus Triatoma can spread Chagas Disease, especially in the new world tropics.

Letter 25 – "Wasp Mimic" Robber Fly

Can’t identify on your site. Bugguide.com or internet
Your site is one of my favorites!!! I scan it weekly. I send several hours learning about the amazing creatures that share this world with us. I do have a bug I have been unable to identify. I have looked on your site, Bugguide and tried every combination I could think of on the internet to identify these little beauties. I live in Navasota, TX and this summer was the first time I have ever seen these guys. Keep up the awesome work!!! Is there anything (besides trying to research on our own first), that we, the grateful readers of this amazing site, can do to help…donations…resources…etc??
Robin

Hi Robin,
We believe these are Wasp Mimicing Robber Flies. They resemble an insect in the genu Ceraturgus on BugGuide, but the match is not exact. By the looks of things, you should be seeing more next year. Thank you for your kind thoughts, but at the moment, we are not set up for contributions. We are still selling our calendars through the gift shop and clicking on some of our ads does help pay the high cost of web hosting. WE are going to try to get Eric Eaton to weigh in on the identification. Eric quickly provided the exact species: “Right family at least:-) These are indeed robber flies, in the genus Laphria. The species is Laphria saffrana, or something like that. That species is also featured on bugguide. Keep up the great work! Eric”

Letter 26 – Bee-Like Robber Fly

Huge Orange Robber Fly
I know you’re swamped, but check out these shots of some kind of large orange robber fly! I’m doing fieldwork in burned forest areas of interior BC and came across this critter one morning on a burned Douglas Fir trunk. I think you can see pupa cases in one of the photos, too… it must have recently emerged. Sadly there’s nothing to indicate scale but I’d say the fly was 2.5-3.5 cm in length. What IS it?!
Shannon

Hi Shannon,
We believe this is one of the Bee-Like Robber Flies in the genus Laphria. We have eliminated the Bee Killer genus Mallophora thanks to this explanation on BugGuide posted by Herschel Raney: “Mallophora Have the very slim antenna tips. Laphria all have the blunted tapered tips.” Your specimen has the blunt tapered antennae. The closest match we can find is Laphria fernaldi, but we would love to get a more expert opinion.

Update: (07/11/2007)
Eric Eaton sent me. His email is glitching. This concerns the Laphria photo from BC with the golden hair and the silver legs. (Now on your robber page.) It is one of the species that Bullington moved out of Laphria proper in his dissertation which has never been published. So we cannot use the other genera names. Dr. Cannings would like to email the shooter about her shot if you can get me the email. Comments from Dr. Rob Cannings in BC. “I’m pretty certain it’s Laphria sackeni Wilcox (apical palp hairs look golden, not black), a widespread Cordilleran species… BC interior and coast north to Alaska…south to California and Colorado. Likes open areas in conifer forests (logged and burned sites) and, like other Laphria species, develops in dead wood.”
Herschel Raney

Letter 27 – Bee-Like Robber Fly

Bee Identification
We came across this bee while hiking on Cougar Mountain near Newcastle, WA. I must have upset it somehow as it swarmed me, flying around my head and finally landing on my leg. Luckily my keys were in my pocket where it landed, so I’m not sure if it tried to sting at that moment or not. I was able to shush it away so it landed on a nearby bench. I took a close photo so I could try to identify this guy when I got home but have been finding it very hard to do so by looking at many sites including yours. Please help me out. It looked really mad and, from the looks of its backend, I’m really glad it didn’t sting me.
~Mark in Tacoma, WA

Hi Mark,
This is not a Bee, but a Robber Fly in the family Asilidae. We don’t immediately recognize your species, and we cannot at the moment research this more thoroughly, but you may have luck researching the BugGuide archives. It is also possible one of our readers will provide the answer. Flies don’t sting, they bite.

Thank you for the clarification. I researched it more and found it most likely to be a Laphria thoracica. I appreciate the help in identifying this species of fly.
Mark

Hi again Mark,
We believe you have the genus correct, but this looks more to us like a male Laphria astur, also pictured on BugGuide. All the photos on BugGuide are collected specimens, so it is wonderful to have a photo of a living example. Collectively, the Laphria species are known as the Bee-Like Robber Flies.

Letter 28 – Bee-Like Robber Fly

Robber
Hi Guys,
In the last year I’ve visited your site many times when I can’t find a bug I’ve captured in my books, in about the same time I’ve been getting into photography mostly bug shots but also animals when I stumble or sneak up on them. I’m no expert, still don’t know what all the buttons are for on my digital SLR but have managed to get a few viewable shots. Just looked through the robber fly section and now know this is a Bee Killer but thought I’d send this in to you as he/she is blowing it’s horn 😉 Taken a couple of weeks ago near Orlando FL where I live, Work has me traveling and I’m now in Massachusetts…..no bugs 🙁 but did manage to get a lovely shot of a Muskrat earlier today, a first. Brilliant site you have
Glen
PS If you get a minute, check out National Geographic website and take a look at July 07 Your Shot page I’m still buzzed

Hi Glen,
We are inclined to identify your Robber Fly as one of the Bee-Like Robber Flies in the genus Laphria as opposed to the Bee Killers in the genus Mallophora because of the difference in the antennae. Mallophora has “antennae with a very thin terminal final segment, whereas Laphria has thick antennae.” We are not exactly sure what you want us to see on the National Geographic “Your Shot” page.

Letter 29 – Bee-Like Robber Fly from Canada is Laphria gilva

what is it?
November 11, 2009
i would like to know what kind of bug this is
Brenda Bouvier
Enterprise Northwest territories

Hi Brenda,
This is a Bee-Like Robber Fly in the genus Laphria.  There are no exact matches on BugGuide, but Laphria janus, which is found in Canada, looks somewhat similar, but with a yellow thorax rather than the black thorax of your specimen.  The Wisconsin Butterflies page shows some mating Laphria janus, and the differences between them an your specimen are even more obvious.  We found a species called Laphria index on the www.hr-rna.com website that also shares some similarities with your specimen.  It is also pictured on the Wisconsin Butterflies website.  Continuing to follow clues, we found an image on BugGuide of a female specimen identified as being in the Laphria scorpio/aeatus group that seems the closest yet, but the abdominal coloration is not exact.  Perhaps one of our readers can assist with an exact species identification.

Daniel:
You are correct on the genus, and it is clearly a male with those big claspers on the tip of the abdomen.  Dr. Robert Cannings in British Columbia would recognize the species right off.
Eric

Dr. Robert Cannings replies:  Laphria gilva
November 15, 2009
Hi Daniel: This is Laphria gilva. It ranges around the whole northern hemisphere in northern coniferous forests (It’s the only holarctic species in the asilid subfamily Laphriinae). In Eurasia it is known as Choerades gilvus. In North America it ranges from Alaska and Yukon east to New Brunswick, south to Pennsylvania, Colorado and California.
Please also let Eric Eaton know its identity. Thanks!
Cheers,
Rob
Dr. Robert A. Cannings
Curator of Entomology
Royal British Columbia Museum

Here is a link to BugGuide with a photo, and one to a European website with wonderful images of mounted specimens.

Letter 30 – Bee-Like Robber Fly

Lake Bug
Location:  Upstate New York
September 5, 2010 12:09 am
Dear Bugman….found this interesting beast on an adirondack chair at a lake in upstate NY. What the bug is it?
Thanks!
Signature:  Ken

Hi Ken,
This is a Bee-Like Robber Fly in the genus Laphria, possibly the Virginia Bee Killer, Laphria virginica.  There are many similar looking members of the genus.  You can compare your individual to the Virginia Bee Killer photos posted to BugGuide.  According to the data page on BugGuide, most sightings occur in June, and they are rare in August and BugGuide reports no September sightings, however sightings for the entire genus reported on BugGuide do include September sightings.

Letter 31 – Beelike Robber Fly: Laphria macquarti

Unknown fly or bee?
Location: Abbeville, Louisiana
April 15, 2011 5:02 pm
Found this bug in my yard today. It is slow moving and stayed stationary a lot.
Signature: Thanks, Marcelle

Hi Marcelle,
This is a Beelike Robber Fly in the genus Laphria, and it fits the description of Laphria macquarti on BugGuide which describes it as:  “Yellow on first few segments of the abdomen and the tibia of the middle leg.”  It is a very effective Bumble Bee mimic.

Letter 32 – Bee-Like Robber Fly

Creepy black and yellow bug
Location: Tuscaloosa, AL
June 2, 2011 11:30 pm
So, this bug landed on my shoe while I was luckily not wearing it. I shooed it away a few times but it kept coming back and landing on that same shoe. Finally, my friend through something in the general direction of the bug (she has horrible aim and didn’t come close to actually hitting it) and it flew away. I grabbed my shoes and left before it had the chance to come back after that, but I was just wondering if you could tell me what it is that was hanging around us.
Thanks 🙂
Signature: Kasey

Dear Kasey,
This amazing predator is a Bee-Like Robber Fly, Laphria saffrana.  We suspect the species name, saffrana, might refer to the legs which resemble saffron, though that is merely a guess.  You can see additional images of this Bee-Like Robber Fly on BugGuide, and it could be noted that the data page on BugGuide indicates sightings from Alabama as well as surrounding states in the South.  Many years ago we posted a photo of a mating pair of Laphria saffrana.

Thanks so much! I think I took the picture back in March, but completely forgot about it until I was going through my camera the other day. I’m glad to finally know what it was, I had never seen one before and I haven’t seen one since.

Letter 33 – Bee-Like Robber Fly

Subject: Is this a bee?
Location: Central Massachusetts
July 7, 2014 10:34 pm
This bee-like creature (larger than a bumble bee) was lurking on my compost bins, where there’s a bumble bee nest. Is this a robber fly?
Signature: Ellen P.

Hi Ellen,
You are correct that this is a Robber Fly in the family Asilidae.  The clublike antennae indicate that it is a Bee-Like Robber Fly in the genus Laphria, which according to BugGuide includes 62 North American species.  Our best guess of the species represented on BugGuide is Laphria champlainii.  We suspect the compost bin is good hunting for the Bumble Bees as these large Robber Flies tend to prefer stinging insects like wasps as bees as choice prey.

Letter 34 – Bee-Like Robber Fly

Subject: Large Bug
Location: Toledo, Ohio
June 4, 2015 5:22 pm
It’s that time of year again where I love to visit your page because I find so many new bugs. I love bugs, but honestly, I hope this one never lands on me as it was HUGE. (Unless I find out it doesn’t sting. ) It was hanging out in an open field in Northwest Ohio with butterflies and other bees. Any idea what it is? I’ve never seen anything like it.
Thank you!
Signature: Ginny

Dear Ginny,
This is a Bee-Like Robber Fly in the genus Laphria, but we cannot be certain which species you sighted.  You can find additional information on BugGuide.

Thank you!  You know, I actually looked up Robber Fly, but didn’t see anything that looked like it.  I will do further looking.  Thanks so much!!
…ginny

Letter 35 – Bee-Like Robber Fly

Subject: Giant “bee”?
Location: Westwood MA 02090
June 30, 2015 7:25 pm
Found this rather Docile, Giant bee like bug today at my camp and could not identify.
About the length of my index finger (3″).
Much larger than a carpenter bee and someone thought it could be an invasive Asian Resin bee, but all pics look again, too small.
Both pics are the same bug.
Help!!
And thanks!
Signature: James R

Dear James,
Your confusion is understandable.  This is a Bee-Like Robber Fly in the genus Laphria, most likely either Laphria virginica or Laphria flavicollis.  Of Laphria virginica, BugGuide states:  “Easy to confuse with L. flavicollis. The main gestalt things to look for are the hairiness of the black abdomen, very fuzzy in virginica but somewhat glossy in flavicollis. The golden hair on the top of the thorax looks more swept back and finely constructed in flavicollis. And in virginica, the legs have a reddish brown tone to the fuzz in good light.”

Letter 36 – Bee-Like Robber Fly

Subject: Wasp, Bug, or Something Else?
Location: Anacortes, WA
June 2, 2016 7:55 pm
This pretty thing was on a stump next to my kitchen garden this morning. It was about an inch long. Can anyone identify it, please?
Signature: Lorien Shaw

Dear Lorien,
This is one of the predatory Bee-Like Robber Flies in the genus Laphria, and we believe it resembles Laphria columbica which is pictured on BugGuide, but we would not rule out another species like Laphria astur which is also pictured on BugGuide, or possibly another member of the genus.  Members of the genus found in the western portions of North America are pictured on swb.usachoice.net. 

After quite a bit of internet research, I had strong suspicion it was likely one of the predator critters, and I’m delighted to have a more specific direction for my queries.  Thanks so much for the assistance!
Els