Robber flies are named after their ability to rob insects of their lives in mid-air! But which insects do they attack? What do robber flies eat? Let’s figure it out.

There are around 7,000 species of robber flies in the world, and nearly 1,000 of them are native to North America.

Robber flies are one of the most fascinating creatures in the insect kingdom. They are known to be excellent hunters. 

These little bugs can catch prey in mid-air, pouncing on unsuspecting bugs that happen to fly past them. In this article, we will talk about what robber flies eat and why this might be beneficial to humans.  

What Do They Eat?

Robber flies (order Diptera, family Asilidae) are excellent hunters and usually prey on smaller insects, but they are also seen attacking insects bigger than themselves. In fact, adult robber flies eat anything that they can hunt. 

Robber flies can also be cannibalistic and larger ones are often seen hunting and eating smaller robber flies. Let us look closely at what they eat. 

Adults

Adult robber flies mostly hunt smaller insects like flies, ants, and more. But they will not hesitate to hunt down bigger insects like honey bees, dragonflies, and butterflies if they get a chance. 

The insects they usually hunt are beetles, flies, moths, wasps, ants, crickets, grasshoppers, lacewings, and mayflies. 

The adults will also pursue other smaller species of robber flies. These flies will also attack humans in the act of defense if they try to threaten them or mishandle them.

Larvae

There is a limited amount of data about what the robber fly larva eats. 

One of the prime reasons behind this is that these creatures live in places like decaying wooden logs or soil, which are hard to access. 

The only known info is that these larvae eat prey like grasshopper eggs and beetle larvae. 

How Do They Hunt?

Robber flies live up to their other name – assassin flies. They are great hunters who often stalk innocent insects passing by an area from a vantage point. 

Once the time is right, they pounce on the prey and inject them with their saliva using their long proboscis (needle-like mouthpart insects use to suck things). 

The saliva contains neurotoxic enzymes that paralyze the target. It also contains proteolytic enzymes and other digestive enzymes that liquefy the inside organs of the hunt. 

One fascinating thing about their hunting behavior is that they usually carry the prey back to their territory before consuming it. 

Once they enter their zone, they rest on the branch to feast on their meal. 

In the case of smaller prey, it can take around 5-15 minutes to finish off the meal; for the heavier targets, it can take up to an hour. 

Adaptations That Help Them Hunt and Eat

These agile hunters have evolved several features that help them to hunt efficiently. 

They are equipped with strong legs, spiky bristles on their body, a long and sharp proboscis, and large compound eyes. 

Let us look at these features in detail below:

Proboscis

The proboscis is one of the primary weapons that a robber fly uses to hunt. It is a dagger-like beak that acts both as a weapon for impaling and as a straw for eating their food. 

The flies use the proboscis to inject saliva into the prey, which paralyzes them. Once the target is paralyzed, they inject digestive enzymes that liquify the internal tissues of the hunt. 

These digestive enzymes do not damage the outer skeleton of the body, but make it easy for them to suck out the juices. 

Once the flies carry the kill to their territory, they use the proboscis to suck the liquid and complete their meal.

Bristles Around The Mouth

If you look closely, you will notice a good bunch of bristle-like hair on their faces (known as mystax) between the eyes and mouth. 

Since they are active hunters and are seen hunting larger prey, these bristles protect the flies from receiving facial damage from the struggling insects when they inject the saliva and impale the prey. 

Several Eyes

Here is one of the most intriguing facts about robber flies, they have more than two eyes. Yes, you read it right! 

Although you may only notice a large pair of eyes on these flies, they do have three simple eyes located on the top of their head in a wedged area between the two big eyes. 

These extra eyes help them to find their prey better and to detect danger in the area that normal eyes can’t. 

Strong Legs

Since these insects often carry their prey back to the territory to eat them, they need a strong pair of legs to help move the weight of heavier insects like dragonflies and bees. 

The legs of robber flies are spiny but tough, and they help them carry weights much larger than themselves.

Lifecycle

The female robber flies lay eggs in areas and plants that are close to the ground or in some corner of a wooden log. 

When these eggs hatch, the larva comes out and lives and grows in soil or in decaying wood. 

These larvae are also predatory in nature and are often seen eating eggs of pest insects like grasshoppers and beetles. 

During winters, robber flies overwinter in the soil as larvae or by transforming into pupae. They come only out of the soil once the temperatures are higher, and they can find ample food for themselves. 

Are They Beneficial?

These flies will consume any insect that they can kill, which means they will remove pests and other beneficial insects like white grubs from your garden.

Also, while they are capable of inflicting pain through their bites, they are great hunters of pests like grasshoppers, beetles, and more. 

These flies are like a mixed blessing to the farmers, as they are capable of killing beneficial insects but also removing almost all unwanted pests from the garden. 

How To Invite Them To Your Garden

Robber flies are omnivorous creatures. Although the central part of their diet consists of insects, they drink nectar from the flowers. 

So if you want to invite these beneficial insects to your garden, try planting more and more flowers. Both smaller and larger robber flies will be attracted to flowers for the nectar. 

Frequently Asked Questions 

Wrap Up

Robber flies are fascinating creatures with unique bodies and a thirst for the hunt like no other. These silent assassins of nature can quickly wipe out an entire garden full of bugs. 

Knowing about these creatures will help you understand them and handle them better. We hope this article provides all the necessary information about these flies.

Thank you for taking the time to read this article. 

Reader Emails

Over the years, we have received several letters from our readers asking us about this most fascinating creature.

Robber flies are also known as hanging thieves because of their habit of dangling from vegetation with one leg.

Please go through some very interesting meal choices for this fly in the letters below.

Letter 1 – Bee Assassin

 

A true bug?
Bugman,
I came across this bug on my sunflower, in Phoenix Az. My grandaughter( 8) just loves bugs and wanted to play with him, she had a great time looking at the photos on your site. After reaching for the camera to snap it first, I scoured your site but still did not find it. It appears to be maybe a nymph of a true bug variety. Could not find a pic just like it though. Your help in identifying it would be most appreciated.
Thanks, Elaine

Hi Elaine,
Bee Assassins are True Bugs, but we have several pages devoted specifically to Assassin Bugs. Bee Assassins are in the genus Apiomerius. Careful, they will bite. Your specimen is a winged adult.

Letter 2 – Bee Assassin

 

here’s my bug
Any clue as to what this interesting little bug is? It has such an interesting pattern on its back and the “belt” around its middle!!! Thank you.
Nikki Humphrey

Hi Nikki
This is a Bee Assassin, Apiomerus spissipes. According to BugGuide: “It pounces on Honey Bees and other pollinating insects. It holds the captive in its powerful legs, thrusts its cutting beak into the victim’s back, injects an immobilizing digestive agent, then sucks out the body juices.”

Letter 3 – Bee Assassin

 

Some type of Leaf or Wood Bug- nice chompers
This fellow was resting on an old windowsill in June. (Location South Carolina) I’m not sure what he is, but I thought his expression was pretty neat and wanted to share him/her.
~Enjoy !~
Melissa ‘Liss ‘ Burnell

Hi Liss,
Your critter is a Bee Assassin, Apiomerus crassipes, one of the Assassin Bugs.

Letter 4 – Bee Assassin

 

Black & Red Beetle-ish Thing
July 14, 2010
Photographed this guy in my friend Ellen’s garden, off Rt. 53 just south of Charlottesville, VA, last month (June). Wondering if you can tell me what it is… Thanks!
Kathy
Charlottesville, VA

Hi Kathy,
True Bugs like your Bee Assassin, Apiomerus crassipes, can be distinguished from beetles by their piercing and sucking mouthparts as opposed to the chewing mouthparts of beetles.  Bee Assassins get their common name from their habit of waiting on flowers for bees and other pollinating insects to arrive, only to quickly become a meal.

Wow, Daniel! Thanks for the quick reply! I appreciate it…
–Kathy

Letter 5 – Bee Assassin

 

This but is eating my bees
Location: Liberty Hill, Texas, USA
May 11, 2011 2:39 pm
Hi bugman,
I am trying to find out what type of bug this is. They are hanging out at my bee hive, grabing one bee and then flying off with it in there mouth.
Do you know what kind of bug this is and how i can keep them away from my bees?
Thank you
++ Paul Dunlap
Signature: Paul Dunlap

Dear Paul,
This is one of the Assassin Bugs in the genus Apiomerus and they are commonly called Bee Assassins.  We believe it is Apiomerus spissipes and you can compare the photos on BugGuide to your specimen.

Thank you very much.  This is exactly what it is!!
Thanks again.
++ Paul

Letter 6 – Bee Assassin

 

Errant flyer
Location: Ft. Lauderdale, FL
May 7, 2012 10:07 am
This little bug flew into me at Ft. Lauderdale Executive Airport @ 3:30 pm on Monday, April 23. The day was partly cloudy & windy in the low 80s. The bug was about 1.25 inches long. It was curious, not aggressive but sensitive to ground vibration (I dropped a screw on the concrete nearby & it reacted). After regaining its bearings, it walked off. I haven’t encountered another one since.
Signature: Jennifer McMullan

Dear Jennifer,
Should you ever again encounter a Bee Assassin, you should avoid handling it.  Though they are not aggressive towards humans, they are a predatory species with piercing mouthparts that suck fluids from their prey.  We have gotten reports of people being bitten by Bee Assassins if they are carelessly handled.  We believe your species might be Apiomerus floridensis based on the images posted to BugGuide.

Letter 7 – Bee Assassin

 

Subject: What is this?
Location: La Marque
November 2, 2012 11:21 pm
Every colorful flower i strolled pass I’d see them covered with these bugs. They dont seem to be camera shy, they allowed me to get as close as i wanted. I didnt get too close because although its colors are inviting and beautiful this could mean danger. What is this bug?
Signature: Thanks in advance, Tx Finest

Dear Tx Finest,
You were wise to be cautious.  This is a Bee Assassin, probably Apiomerus spissipes, though it may be another member in the genus.  They are predators with piercing mouthparts, and though they are not aggressive towards humans, they might bite if carelessly handled.

 

Letter 8 – Bee Assassin

 

Subject: Milkweed Assassin Bug on Milkweed?
Location: Coryell County, central Texas
April 27, 2013 3:37 pm
I went in search of wildflower photo ops today, and also found some interesting insects. Is this a milkweed assassin bug on the milkweed? I took its red coloration, bright patterns, and Sumo-wrestler stance as warnings, and kept my distance. Good old zoom lens 😉
Thank you for any help in identifying this insect. I couldn’t seem to spot an exact match: http://bugguide.net/index.php?q=search&keys=milkweed+assassin+bug
Signature: Ellen

Subject: Part II of Possible Milkweed Assassin on Milkweed
Location: Coryell County, central Texas
April 28, 2013 12:28 am
After looking at your ”assassin” archives, I’m beginning to think that the possible assassin bug I photographed yesterday may be a Bee Assassin, possibly a Yellow Bellied Bee Assassin, although it has a striped belly. I’m attaching a photo that shows the belly.
After reading through your archives and seeing how often your readers have received painful bites from assassin bugs, I’m extraordinarily thankful that I kept my distance from the handsome creature.
Thank you!
Signature: Ellen

Dear Ellen,
We are very happy that you correctly identified this Bee Assassin in the genus Apiomerus.  We do not believe that it is a Yellow Bellied Bee Assassin, Apiomerus flaviventris, as the species is only reported from Arizona and California as well as Mexico according to BugGuide.  It looks to us like a Bee Assassin, Apiomerus spissipes, and you can compare images on BugGuide which look very much like your individual.

Subject: Part III Possible Milkweed Assassin Bug on Milkweed?
Location: Coryell County, central Texas
April 28, 2013 9:07 am
Well, it looks like I’m zero for two on this one. Although this red insect was near the milkweed, it looks upon further review as though it’s actually on a Texas primrose. Attached is a blurry image of the insect as it flies to another plant, primrose in the background. Sorry, and it’s a good thing I’m not trying to make a living as a field biologist, eh? Here’s a link to the Texas primrose, a very beautiful wildflower. http://paintedflowerfarm.com/pages/plants/natives/primrose,texas.htm
Signature: Ellen

Don’t be so hard on yourself Ellen.  You did eventually correctly identify the Bee Assassin.

Letter 9 – Bee Assassin

 

Subject: Bee eating Bug!
Location: Ogden Utah
July 20, 2017 9:44 pm
Hi! My friend in Ogden, Ut found this wee monster making a meal of her bees.
We can’t find a similar looking critter anywhere on Google, so I realize it could be a juvenile of some species or other, but…we’re stymied.
Signature: Philina

Dear Philina,
This is an Assassin Bug in the genus Apiomerus, a group commonly called the Bee Assassins.  We are relatively confident your individual is Apiomeris montanus based on this BugGuide image.  Is Ogden at a high elevation?  The habitat, according to BugGuide is:  “Mountainous regions. Collected from 1075-2896 meters. “

Daniel, thank you! Ogden is at about 4800 feet, and right up in the foothills. So yeah, mountainous is a good word.
Any suggestions for my friends whose apiary is under attack?
Natural repellents?
Thank you!

Sorry Philina, we do not offer extermination advice.

Oh, she doesn’t want to exterminate them, just keep them away from her hives. I was thinking more like, if she sprinkled cayenne pepper around the hives, they don’t like it and won’t come by it, sort of ideas. But now that i read they can fly that’s not really useful anyway.
Thanks for the help in identifying it though. We were all making good guesses, but couldn’t find any matching pictures.

Letter 10 – Bee Assassin eats Bee

 

Assasin But snacking honey bee
December 13, 2009
I took this while shooting a butterflies in Lamspasas, Texas, USA.
mikel68
Lampasas, Texas, USA

Dear mikel68,
Your photo of a Bee Assassin, Apiomerus spissipes, feeding on a Honey Bee is beautiful.  You can see additional images of this species on BugGuide.

Letter 11 – Bee Assassin eats Japanese Beetle

 

assassin but
Hi.
I live in Cleveland Georgia. My apple tree is being eaten by Japanese Beetles. I read quite a bit about them on the web and mostly learned there are no nature enemies of them. BUT a couple of days ago when I was picking them off my tree, I ran across this threesome. Only 2 of the bugs are clear – the dead/dying J/B and the bug on the bug eating the J/B. I’ve been told it is an assassin bug and after searching the web, I’m figuring it is the blood sucking conenose. Is it? Since this pic, I have found another one in a flowering bush that also is infested with J/B’s. They have not acted aggressive, even when I have almost touched them. Because they like the beetles, I don’t want to run them off!!! Thanks,
Beth

Hi Beth,
We are guessing that you meant Assassin Bug and not “Assassin But” in your subject line. This is not a Blood Sucking Conenose. It is a Bee Assassin, Apiomerus crassipes and BugGuide has a detailed photo for comparison. We doubt that there are enough predators out there to significantly curb the Japanese Beetle emergence each year, but it is nice to see the Assassin Bugs are trying.

Letter 12 – Bee Assassin from Panama

 

Subject:  Bug
Geographic location of the bug:  Panama
Date: 11/14/2019
Time: 07:26 AM EDT
Your letter to the bugman:  Found this bug in El Valle..700m
Thanks for any comments
How you want your letter signed:  Jerry Harrison

Dear Jerry,
This is a predatory Assassin Bug and it sure looks to us like a member of the genus Apiomeris, the Bee Assassins.  We found a FlickR posting that looks exactly like your individual and it is identified as possibly Apiomeris hirtipes.

Letter 13 – Bee Killer

 

Fly or Bee?
Hi,
I find this bug every year on my tomato plants and was wondering if he is some kind of carpenter bee or sawfly? I live in Southern Calif. Thanks,
Suzanne

Hi Suzanne,
This is a Robberfly. More specifically, it is a Bee Killer in the Genus Mallophora. We don’t recognize the species. The red legs are quite distinctive.

Letter 14 – Bee Killer

 

I need help identifying something strange (like you don’t hear that all the time). I was out on my porch the other day when I heard a buzzing sound from what I assumed was some sort of beetle or something. There are a lot of bugs around our wooded lot in western Virginia, so I didn’t think anything of it until it landed on the chair next to me. It was big (about 2 1/2″ long and fairly “beefy”), blackish, and resembled a locust except for the soft yellow and black ringed body that tapered to a point at the end. I couldn’t see the wings while it was sitting there, but obviously it had some. I was immediately reminded of something from a sci-fi movie or a prehistoric critter on the Discovery Channel. I’ve looked everywhere and can’t find any descriptions or pictures resembling it. However, I’ll certainly be sure to take my camera with me whenever I take a cigarette break from now on.
-Michaele
(08/16/2004)
This is quite coincidental, in fact, because not two seconds before I checked my e-mail, it had returned out on my front porch and I was able to snap a picture. It’s not very good because I couldn’t get too close before it flew away, but here it is.
Michaele Davis

Hi again Michaele,
I’m glad you got the photo. You have a species of Robber Fly, Family Asilidae. These are predatory flies that it locates with those big eyes and often captures on wing. They are beneficial, though will bite people if mishandled. Based on your original description and your blurry photo, it seems like you have a Bee Killer also known as a Giant Robber Fly, Promachus fitchii. They are found in meadows and near honey bee hives from Massachusetts to Florida and west to Texas and North to Nebraska. According to our Audubon Insect Guide: “The Bee Killer often rests on leaves and branches with a clear view of flowers visited by Honey Bees. It seizes its victim from above, pierces its body and sucks out juices, then drops the emptied prey. A dozen or more bidies may pile up on the ground below a favorite perch.” Size can be deceptive. This species reaches 1 1/8 inches in length.

Letter 15 – Bee Killer

 

Goggles and purple legs – SoCal backyard visitor
Saw the guy in the attached photo in my backyard this afternoon (July 23) here in Culver City, California. He liked clinging to long stalks of overgrown grass, and never flew away very far. His legs were a dark purple-ish color, and his eyes look like big goggles. He seems like a bee of some kind, maybe a leaf cutter? Any insight you can offer would be much appreciated. Best,
J

Hi J,
This is a Robber Fly in the genus Mallophora, known as the Bee Killers. According to BugGuide, there is only one species in the genus in California, Mallophora fautrix. Your photo is consistant with the images of Mallophora fautrix posted on BugGuide.

Letter 16 – Bee Killer

 

Subject:  Bee Fly?  Laphria thoracica?
Geographic location of the bug:  Carlsbad, NM
Date: 11/16/2017
Time: 10:40 PM EDT
This guy (or gal) was hanging out on our screen door in early August of this year.  He didn’t seem to mind when we went in or out, and he didn’t mind being photographed.  Eventually, he flew away.  He looked like a bee crossed with a big fly.  We don’t recall seeing such a colorful one before.  We searched your site and a few others on the internet.  We think he looks like some of the Laphria Thoracica on Bug Guide but not exactly.  We were hoping you might know.  Thanks for all the time and hard work you put into your site.
How you want your letter signed:  Curious

Dear Curious,
This is a Robber Fly, not a Bee Fly, and you do not have the genus correct.  It is NOT Laphria thoracica, as that species has a yellow thorax based on BugGuide images, and your individual has a black thorax.  In our opinion, this is a member of a different genus of Robber Flies.  We believe it is a Bee Killer, Mallophora fautrix, a species pictured on BugGuide can be distinguished from the previous genus and described on BugGuide as “Large, fuzzy, bee-mimicking robber flies. Resemble Laphria, another genus of robbers that mimic bumblebees, but is even hairier and has antennae with a very thin terminal final segment, whereas Laphria has thick antennae.”

Letter 17 – Bee Assassin

 

Subject: Is this a kissing bug?
Location: North Central Alabama
May 1, 2016 12:56 pm
We found this bug in our home in Alabama and are concerned that it might be a kissing bug. We would appreciate any information on what bug this is and if it is a kissing bug, what do we do to insure we don’t have any more in our home?
Signature: Alabama Fan

Dear Alabama Fan,
We have gotten numerous identification requests over the past year since there has been increased news coverage on Kissing Bugs and most have proven to be other species.  In your case, though your image lacks critical clarity, it appears that this really is an Eastern Blood-Sucking Conenose Bug or Kissing Bug, Triatoma sanguisuga.   Tropical members of the genus are most likely to spread Chagas Disease, but BugGuide does note:  “Sometimes bites humans, and the bite may be severe, causing an allergic reaction.”  Insects can enter homes through open windows and doors, gaps in the frames of windows and doors, and cracks in the foundation.  You should do a thorough inspection to determine the likeliest places an insect might gain entry and seal those points.

Thank you very much for the prompt response. My husband killed it and thankfully no one has any bites of any kind.  We will definitely be checking for any entry points and seal them.
I truly appreciate your help.

Update:  After a comment from Cesar  Crash and then Alabama Fan agreeing with Cesar, we are making a correction to the identification of the insect we now believe to be a Bee Assassin.

Letter 18 – Robber Fly eats Dragonfly

 

me again:)
I found this predator while walking in the upstate ny woods. I was looking for butter and dragon flies with my camera in hand and this wasp-looking thing landed in front of me then quickly flew off. What bug catches an aeronautic master like the dragonfly.(if that’s what is being eaten)
Thanks,
torch

Hi again Torch,
This is an amazing image of a Robber Fly. These winged predators might have dragonflies beat when it comes to aeronatic maneuvering.

Letter 19 – Robber Fly eats Bee

 

From South Africa …
Hello,
I just found your site. It’s really nice and informative – well done! I hope this picture will be of some interest. If you look closely, you will notice that there seem to be three insects involved: a robber fly (I presume), a bee (honey bee?) and a tiny “bee-like” insect. I would be most interested to hear what you make of this.
Regards,
John Skliros
Kloof (20km west of Durban) South Africa

hi John,
Well, you most definitely have a Robber Fly feasting on a Honey Bee. The other insect looks like some typ of Fruit Fly, but we are not certain.

Letter 20 – Robber Fly eats Sulphur Butterfly

 

Your Predator and Prey Page
Dear Bugman,
I have a couple of images that I would like to have submitted to your “food chain” page..I am from upstate new york, which is where these images were taken. The first is a robber fly (with what looks to be a cabbage white butterfly). The second image is of a green dragonfly with some sort of small white moth in its mouth…not sure what “type” of dragonfly it is, or what kind of moth…but thought they were fairly interesting!
Christina

Hi Christina,
The Robber Fly is eating a Sulphur Butterfly.

Letter 21 – Robber Fly eating Honey Bee from Australia

 

PLUS BONUS BUG MURDER
Hi Bugman.
Love your work, and I’m overjoyed to have discovered your site – identifying bugs online is almost impossible as I’ve not found a handy online key thingy, e.g. Does it have 6 legs? Y/N, Does it have wings Y/N (where each Y and N is a link to the next question page, all the way to the final answer). The special offer today is a few somewhat unfocused shots of a bee being impaled against a flyscreen by what looks like a big horsefly (taken at my home in Sydney). It has a huge proboscis that was pinning the poor honey bee down and appeared to be sucking the life out of it. The murderer flew off leaving the desiccated bee stuck to the screen. Many thanks in advance for your help,
Aidan
P.S. Will I get an email if you post your identification(s)?

Hi Aidan,
Your murderer is some species of Robber Fly.

Letter 22 – Robber Fly with Wasp Prey

 

Wasp Attack
Here are two wasps that do not appear to be of the same species. The guy underneath is slowly spitting out drops of clear liquid. The guy on top is attached to the lower one’s rear end.
Bart Hansen
central VA

Hi Bart,
Your subject heading would more correctly read Wasp Attacked. The attacker is a Robber Fly. These swift predators swoop down on unsuspecting wasps, bees and flies. Flies do not chew food, but inject a fluid that predigests the internal organs which are then sucked out, leaving an empty shell behind.

Letter 23 – Robber Fly preys upon a Green Bottle Fly

 

What is this bug
I have been surfing the internet trying to find out what this is. I have it live in a baggy with its dead fly it was eating. It seems very aggressive towards me when I move the bag. It was in my garden window.
Sharon

Hi Sharon,
Great photo of a Robber Fly, Family Asilidae, preying upon a Green Bottle Fly. Robber Flies are common, swift-flying predators. They pounce upon resting insects from above and use the short, strong proboscis to drain their prey’s body fluids, according to the Audubon Guide. On a more personal note, please release it. Sharon, you would act aggressively if someone put you in a bag, wouldn’t you?

Letter 24 – Robber Fly eating Wasp

 

What is it..
You wouldn’t happen to know what this is. I live in Crosby Texas and found this bug on my patio.

Awesome photo of a Robber Fly dispatching one of the Thread Waste Wasps.

Letter 25 – Robber Fly eats Mantidfly in Australia

 

Promachus rufipes with a Mantidfly Lunch
Hi Bugman,
Thanks for posting my pic of the Swallowtail caterpillar. Hope you like this one of Promachus rufipes with a Mantidfly Lunch Gold Coast, Queensland, Australia. April 2007
Trevor Jinks

Hi Again Trevor,
Your photos are very nice, and additionally, they are small files. We are still having problems getting large images. This image of a large Robber Fly will also be a nice addition in our Food Chain section.

Letter 26 – Giant Robber Fly eats Yellow Jacket

 

VERY LARGE ROBBER FLY
I’VE ALWAYS CALLED THEM PREDATOR FLY..BUT IT SEEMS IT’S A ROBBER FLY. THIS VERY LARGE ONE WAS ON MY DECK RAIL. IT’S LENGTH IS AT LEAST 2″, THE LARGEST I’VE EVER SEEN. THAT YELLOW JACKET IS ABOUT 5/8″ LONG TO GIVE A COMPARISON. JUST WANTED TO SHARE.
RON.

Hi Ron,
Your Giant Robber Fly is sure impressive, and justifiably earns the name Predator Fly. We believe this is Promachus hinei.

Letter 27 – Cannibalism: Robber Fly devours Hanging Thief

 

Thanks !
I wanted to let you know how much I appreciate your website. I have come to your site at various times this past summer to find out what creature was lurking in my backyard. My first visit was to find out what a Wheel Bug was and lastly I found information on the Bearded Robber Fly and a Hanging Thief. Thanks again for all the valuable information you provide. I have included photos of my latest inquiry ! Regards,
Dawn Werner
Southwest Ohio

Hi Dawn,
What an amazing documentation of a Robber Fly in the genus Promachus feeding on a related Hanging Thief. We found a website with great photos that identifies your species as Promachus vertebratus.

Letter 28 – Jumping Spider eats Robber Fly

 

spider eating robberfly
I was walking by one of my flower beds and happened to see this spider grab a Robber Fly. I was wondering what kind of spider it is. I only got the one picture before the spider ran away dragging his meal along with him. I appreciate any help you can give me. Thanks…..
Marsha Denney, SW. Missouri

Hi Marsha,
This is a Jumping Spider in the genus Phidippus. It might be Phidippus apacheanus, a female.

Letter 29 – Giant Robber Fly with Prey

 

Hello Bug People!
My daughter and I were quite surprised when this large insect buzzing around our deck returned with a yellow jacket for lunch. I was able to capture the Kodak moment, and with your website, identified the insect as a Robber Fly. What a brave guy — out catching bees (how DO they do that?!) and not a bit fazed by a camera in its face… Blessings,
Cindy

Hi Cindy,
Judging by the prominent beard and the large size, this must be a Giant Robber Fly in the genus Protacanthus. Thanks for getting up close and personal.

Update:  August 14, 2011
In doing some site maintenance, we realized we never properly identified this Red Footed Cannibalfly.

Letter 30 – Bee-Like Robber Fly eats Japanese Beetle

 

Is this a Robber Fly?
I see that many of the pictures identified as Robber Flies look very different from each other. Some are slender and dark, others look like mutant, Klingon bumblebees. Anyway, this guy really gave me a start when I nearly brushed the leaf he was on with my head. He took off, but was back several times, once with a meal (I don’t mind anyone making meals of the Japanese Beetles.) Is something like this harmless to mammals, or does it have a bite/sting/searing wit/whatever?
Tom K.
Massachusetts

Hi Tom,
This is one of the Bee-Like Robber Flies in the genus Laphria. We are not certain of the species, but there are many pictured on BugGuide. Sadly, too few things in the world are damaging because of their searing wit. Robber Flies do not have stingers, but if handled, we suspect they can bite. They will not attack unprovoked.  We wish more predators fed on the invasive exotic Japanese Beetle.

Letter 31 – Bee-Like Robber Fly eats Damselfly

 

Attention … Bee-like robber fly
Hi Bugman:
I was photographing damselflies this past weekend when this robber fly flew past my face and landed on a nearby leaf. Obviously it was interested in damselflies as well. I don’t think there is a common name for this creature other than bee-like, beeish or bumblebee robber fly in the genus Laphria. I believe this is L. janus, but perhaps you could confirm this for me. The photo was taken along a forest trail in an aspen parkland area of southwest Manitoba. Thanks, and regards.
Karl

Hi Karl,
Your Bee-Like Robber Fly is in the genus Laphria, and it doesn’t exactly match any of the species on BugGuide. We tried searching for photos of Laphria janus online but our intermittant connectivity problem returned. When our connectivity returned, we found some support to your identification and we agree this is Laphria janus. A Robber Fly webpage makes this observation: “Note the contrast in the hair color from thorax to abdomen. And note the thoracic hair is not in a triangular and elongate arrangement and it is not spread over the whole thorax. Also note the heavy golden beard and mystax of the female. “

Letter 32 – Bee-Like Robber Fly eats Japanese Beetle

 

Bee or a Fly?
Bugman,
I took this picture on 7/3/08 in the mountains near Helen, GA. It startled me as it flew by because I have never seen anything like this. I have seen the large Cicada Killer flying with a Cicada in its grips and that is an impressive site to see. But, I have not seen this insect before. It apparently has a Japanese Beetle in its grip. Is this a bee or a fly?
Patrick Crone

Hi Patrick,
This is a Bee-Like Robber Fly in the genus Laphria, but we are not certain of the species. BugGuide depicts several possibilities, but nothing looks exact and we feel a true expert is needed to be conclusive. People currently being plagued by the invasive Japanese Beetle will be happy to see your photo.

Letter 33 – Robber Fly eats Wasp

 

What is going on here?
This creature landed on my window long enough for me to take the picture and then flew off for parts unknown. What captured the wasp? I overexposed the print for more detail.
Lauren Birthisel
Fort Worth, Texas

Hi Lauren,
We do not have the necessary skills to count wing veins nor antennae segments to exactly identify the insects in your photo, and the angle is an unusual one for comparison to usual photographs. We would wager this is a Robber Fly, but are not confident enough to take the ID any further. We will try to contact Eric Eaton to get his opinion on both the fly and wasp.

Update: (03/26/2008)
Hi, Daniel:
The fly is a robber fly in the genus Mallophora. The victim is a paper wasp in the genus Polistes.
Eric

Letter 34 – Bee Killing Robber Fly

 

bee like creature frightens dog
Hi!
Yesterday, ur dog Ellie alerted us to this bee-like creature in our backyard. It was frightening enough to throw her into a barking fit. Was she wise in warning us, or is this big guy harmless? (He/she is around 2 inches long..that is the bug not the dog.)
Thank you!
Amy Holloway
Austin, TX

Hi Amy,
This is actually a Robber Fly in the Family Asilidae and it preys on bees. It is harmless to you and your dog, but if you try to pick it up, it will probably bite.

Letter 35 – Robber Fly eats Sulphur Butterfly

 

What is this bug?
This wasp looking thing was found stalking butterflies on the Mogollon Rim area of Northern Arizona around Payson
Thank you

This is some species of Robber Fly, but we have not been successful in locating a match on BugGuide.  The red wings are quite distinctive.  The prey is a Sulphur Butterfly.  We hope Eric Eaton can assist us in the identification of your Robber Fly.

Letter 36 – Robber Fly eats Bee in Australia

 

Robber eats bee foodchain
Sun, Mar 8, 2009 at 11:34 PM
Hi guys,
This robberfly has caught itself a native bee. It is dull and windy here today with a cyclone off the coast so I took the flash with me and was quite pleased with the result. Hope you like it too.
aussietrev
Queensland, Australia

Hi Trevor,
Thanks for sending us a photo demonstrating your new technique. It looks like a studio portrait. We are a bit behind in our posting since we have embarked upon fulfilling a longtime desire to establish a home aquarium. This endeavor has occupied much of our free time since the cabinet needs to be stained and sealed before we can even begin to stock the aquarium with freshwater Amazon species.

Letter 37 – Jumping Spider eats Robber Fly in Australia

 

Salticid kills Asilidae Foodchain
Sat, May 23, 2009 at 10:09 PM
Hi guys,
Got this picture today of a Jumping Spider catching a tiny Robberfly. The spider is one I have been trying to identify with the help of the University of Southern Queensland but there are over 500 species most of which have never been photographed so it is proving quite difficult. Hope you like the shot
aussietrev
Queensland, Australia

Hi Trevor,
We cannot believe how far we had to go back in our email inbox to retrieve your letter which we were too busy to post when we first noticed it.  Summer is approaching in the northern hemisphere and our mail is increasing to the point that we must virtually ignore much of it.  Thanks for sending us your awesome image of a Jumping Spider feeding upon a Robber Fly.

Letter 38 – Bee-Like Robber Fly eats Japanese Beetle

 

Giant bee eating Japanese beetle
July 30, 2009
Hello!
While working in my garden, i came across what appeared to be a giant bumblebee eating a Japanese beetle. The bee had a fuzzy abdomen that was striped yellow and black. It was between 1 3/4 ” and 2 ” long. The Japanese beetle was 1/2 ” long. The bee was flying around holding the beetle in it’s mouth. It was huge! Any ideas on what it is?
tree
Floyd county, VA

Hi tree,
About a week ago we receive a question if Robber Flies ate Japanese Beetles.  We wish your photo had arrived before we answered.  Since Japanese Beetles are an invasive exotic species that does considerable damage to ornamental plants, many gardeners would welcome these Robber Flies into their yards, including our own mother in Ohio.   This is a Bee-Like Robber Fly in the genus Laphria, which can be distinguished from the genus Mallophora by the antennae.  This is explained on BugGuide on the Mallophora genus page thus:  “Resemble Laphria, another genus of robbers that mimic bumblebees, but is even hairier and has antennae with a very thin terminal final segment, whereas Laphria has thick antennae.”  Based on images posted to BugGuide, we believe your specimen most closely resembles Laphria grossa, but we would like an expert confirmation on the species.

Letter 39 – Robber Fly eats Grasshopper

 

Carnage, Purely Natural!
August 10, 2009
Thanks again for providing such a great resource. I have e-mailed before about a Regal Jumping Spider in October of 2008 and have used your archives so many times to identify the critters I stumble across. You were a help again today to identify this Robber Fly that I photographed today at Troy Springs State Park in north-central Florida. Your previous example was unfortunately squished so I thought I would share my photos of a Robber Fly doing the squishing… or sucking. I also hope that you don’t mind that I recommended your page on my blog, 365 Days Through the Eyes of a Park Ranger (www.rangervision.blogspot.com).
Keep up the great work and thanks for the effort that you put into this site even with your busy schedules.
Amy
Branford, FL

Hi Amy,
First we must clarify that we do not consider Food Chain images to be carnage.  Carnage is senseless slaughter.  Your photo depicts the beauty of the natural world.  We are honored to be recommended on your blog as we have tremendous respect for park rangers.  We believe your Robber Fly is in the subfamily Asilinae which has many genera represented on BugGuide, but we are uncertain of the genus or species.  Perhaps a specialist in the Family will write in and assist in this identification.

 

Letter 40 – Giant Robber Fly eats Buckeye Butterfly

 

Asilidae help
June 6, 2010
hello Bugman this is my first time doing this so bear with me. I am a 24year old aspiring entomologist from portage county (NE) Ohio. Besides the average ‘prairies and meadows bordered by woodlands’ can you reveal more information on where to find Promachus robberflies in this area? Your information will be greatly appreciated.
sincerely, Ben
hope this helps,
portage county ohio

Dear Ben,
This sure is a spectacular photo of a Giant Robberfly in the genus Promachus feeding on a Buckeye Butterfly.  Since we do not collect insects, we cannot offer much advice on where to hunt, and the information you provided on prairies and meadows is already indicated on BugGuide.  Perhaps one of our more knowledgeable readers will provide a comment on your posting.

Letter 41 – Robber Fly

 

Yellow Bug found in Canyon de Chelly, AZ
July 15, 2010
My company takes a yearly overnight hiking trip in to Canyon de Chelly, a joint US National Park and Navajo Nation National Park. The first photo below was of a bug I’d never seen before. I grew up in Arizona (though, admittedly, not on the Reservation), and I’ve seen a lot of weird bugs. This one, as you can see, is yellow and brown, has great bug eyes, six legs, and wings. I don’t know the size, as this trip was a year ago, and I only found out about your site tonight. Its upward curved-nose is, to me, it’s most distinctive feature, but I’m no expert.
This year, my brother was on a trip to Mexico, and posted the second photo below. I believe the two bugs look very similar, though my Park-Guide fiancée disagrees. My brother has not yet returned from Mexico, and I’m not sure of the size of his bug, either. His was found on an organic coffee farm in (I think) Chuxnaban, Oaxaca.
Greenbandit
Canyon de Chelly, AZ, USA and Chuxnaban, Oaxaca, Mexico

Dear Greenbandit,
Both insects are Robber Flies in the family Asilidae, but the image from Oaxaca does not have enough detail for us to say much more.  The Arizona specimen might be a Hanging Thief in the genus Diogmites, many of which have green eyes, but we cannot find a match on BugGuide.  We will contact Eric Eaton who is familiar with Arizona insects to see if he can confirm that your Robber Fly is a Hanging Thief in the genus Diogmites.

Eric Eaton Responds
Daniel:
I’m not the best one to ask about these….Reminds me a little more of Blepharepium, though, with the shorter, stouter abdomen….
http://bugguide.net/node/view/323611/bgpage
Still, I’d have the person submit a copy of the image to Bugguide where the real experts can have a look.
Eric

Letter 42 – Robber Fly eats kin

 

Robber fly
Location:  Fairfield, Maine
August 3, 2010 9:40 pm
Dear Bugman,
I was taking photos of this Robber fly on my hammock stand, when it swooped at my face and caught a flesh fly (I think) right in front of me and landed back where I was photographing it to eat. I have checked BugGuide and believe this is female Efferia pogonias. Does it have a common name or nickname? Do you know what the little honey-colored sacs on its sides are? There is one between the wing and the behind the wing and the ”shoulder” of the hind-most leg. You can also see them looking down through the wings from the top.
Thanks
James R

Hi James,
We cannot tell if the prey in your photo is a Flesh Fly, but it is definitely another Dipteran.  You may be correct that this is Efferia pogonias based on images posted to BugGuide, but we believe, based on the shape of the tip of the abdomen, that this is a male.  Perhaps someone with more experience can confirm.  The vestigial wings you asked about are known as halteres, and they are primarily for balance according to the Orkin Fly Anatomy web page.  According to BugGuide:  “haltere noun, plural halteres. – two small knobbed appendages rising from each side of the thorax in the order Diptera just where the posterior pair of wings would arise were they present, and to which they are analogous. They tend to balance the insect in flight.“

Hi Daniel,
Thanks for the I.D. and extra info!
I never would have guessed those were vestigial wings;  What a cool feature.
Best regards,
James

Letter 43 – Robber Fly eats Bee

 

Fly, Dragonfly, Bee Killer wasp?
Location:  Bismarck, North Dakota
August 7, 2010 1:39 am
I took photos of this insect today. It originally flew around my flowering basil, mimicing the bees, going from flower to flower. Then I saw it grab a bumble bee, to eat it. I wrote about it on my blog today: http://sewartfullyminded.blogspot.com/2010/08/bee-fight-and-bee-killer.html
At first glance I wondered if it was a dragon fly because of the long tail, but it behaved differently. It is fuzzy like a bumble bee but has such huge eyes. I followed it taking photos. It didn’t seem to like that and tried to evade me. It landed on the grape leaf and as I continued to take photos it eventually retreated behind the leaf.
Doreen

Hi Doreen,
This adept predator is a Robber Fly in the family Asilidae, and we believe, due to its size, that it is in the subfamily Asilinae, but we haven’t the time to research the species at the moment.  You may view some possibilities on BugGuide.

Letter 44 – Robber Fly eats Bumble Bee

 

Ugliest Wasp EVER
Location:  North Texas
August 14, 2010 6:30 pm
Can you tell me what kind of wasp this is? This wasp will attack flying insects in the air,and if it catches them, seems to attach itself behind the insects head. Sucking out vital fluids perhaps? Also, when this wasp flies, it makes itself appear larger by keeping forelegs up above it’s head. Today one caught a bumble bee of which is in a couple of the photos.

I do not know how it nests, I only notice these individually, on my blooming plants just waiting for a chance to catch something.
Curious about the ugliest insect I have ever seen.

Dear Curious atuiIhes,
This is a Robber Fly, and it is one impressive creature.  It looks very similar to the Hanging Thieves in the genus Diogmites, but not quite.  We searched BugGuide for related genera, and it most resembles members in the genus Saropogon, but there were no matches on BugGuide.  By doing a web search for Saropogon, we discovered the Key to the Saropogon of the United States page, and the description that seemed closest to your specimen is Saropogon birdi.  We searched that and came up with a photo on Flickr that looks identical to your specimen.  We also located a Midwest Biological Control News page entitled Know Your Friends with this tidbit on another member of the genus Saropogon:  “Saropogon dispar is the most injurious of a number of species in Texas that frequent apiaries — more than 700 of these flies were destroyed in one bee yard in a period of three days!”  We are relatively confident your Robber Fly is in the genus Saropogon, but we would like to try to consult an expert in the family for confirmation.  We will see if Eric Eaton can recommend a Robber Fly expert.

Daniel,
Thank you very much for getting back to me. After submitting the photos I looked at your bug of the month and kind of figured it out although I thought it was a hanging thief, it just didn’t hang.. lol    The next day I was out taking pics of butterflies, and one of the robber flies landed on my camera, I almost dropped the camera.. It was probably just trying to be friendly. Right!  Anyway, thank you so very much and I will be happy to know exactly which robber fly this is.
Rhonda, still slightly curious. 🙂

Update on Identification
August 17, 2010
Hi Rhonda,
We are still waiting to hear something from Robber Fly expert Dr. Robert A. Cannings, Curator of Entomology at the Royal British Columbia Museum who we emailed after posting your letter.

Update from Dr. Robert A. Cannings
August 18, 2010
Hi Daniel:  I don’t know Saropogons well, although I think you are
correct in assuming this is one. I’ve sent the photos to Eric Fisher in
Sacramento to check but he hasn’t replied yet. I’ll let you know when he
answers.
Cheers,
Rob

Update:  confirmation of Saropogon
August 26, 2010
Daniel, Eric Fisher says it looks like Saropogon combustus. So there you
are!
Cheers,
Rob

Letter 45 – Common Yellow Robber Fly eats Dragonfly in Australia

 

Dragonfly hunter
Location: Sydney Australia
March 9, 2011 11:57 pm
Dear bugman,can you please identify this
fearsome looking dragenfly hunter ,I found in my garden this morning?
King Regards
Signature: Katja

Hi Katja,
The Robber Fly in your photo looks like an especially large specimen, and large Robber Flies are capable of snatching large flying prey on the wing.  They are formidable hunters.  We believe we have properly identified your Robber Fly as the Common Yellow Robber Fly, Ommatius sp., by comparing your photos to those posted on the Insects of Brisbane website.

Letter 46 – Robber Fly eats Deer Fly

 

Robber Fly eats Deer Fly
Location: Clarksburg, MA
July 29, 2011 9:18 am
This is not the Red-Footed Cannibalfly, but still a very cool bug out here in Western MA! Photos are from July 13. (I’ve pasted my comment/story from the RF Cannibalfly post). Thanks!
True story: so I’m out in my backyard looking for bugs to photograph, when I find this robber fly sitting on a fence rail. I approach with the usual care to get as close as possible, but I am having difficulty because of the summer menace in Western MA known as “DEER FLIES.” The only natural way to keep them off of me (that I’m aware of) is to have my dog by my side because apparently dogs taste better to deer flies — anyway I wasn’t subjecting Molly to that torture, so they are distracting me, buzzing around my head when the robber fly takes off right for me. I first thought I was annoying it and had provoked a warning buzz or something, but then I noticed it had landed not too far from its original parking spot. As I got close again, I saw that it now had lunch: one of the deer flies just buzzing around my head! Talk about my hero! I ended up taking quite a few pictures of it and its prey, which can be tricky because I don’t like to scare off bugs from hard -earned meals (I guess it wasn’t that hard-earned in this case, but still). I thought I had done just that when the robber fly left its prey on the fence, only for it to do another buzz-by and land with another deer fly!
Thusly, all I can say is, robber flies may not be man’s best friend, but they might be a close second. (They also deserve a nomination for dog’s best friend.)
Signature: Michael Marlow

Hi Michael,
Thanks for repeating your story along with photos that illustrate it properly.  Robber Flies are truly amazing predators.

Letter 47 – Bug of the Month #2 August 2011: RARE Bee Killing Robber Fly eats Honey Bee

 

Ed. Note:  February 21, 2014
It has just come to our attention that this is one of the rarest North American Robber Flies, Dasylechia atrox, and more information can be found on BugGuide.

Carnivorous bumble bee?
Location: Royal Oak, MI
August 2, 2011 2:15 pm
We have a honey bee hive in our yard and have been very bug friendly. We have cicada killing wasps in our driveway and we just steer clear of them instead of filling it with concrete.
Imagine my shock when I was hanging laundry out and saw one of our honey bees having the life drained out of it by what appears to be a bumble bee. Is it?
Signature: Jessica

Hi Jessica,
We absolutely love your email, and we would like to wax poetically after we answer your question.  This is a Robber Fly.  It is one of two genera that both feed on large flying insects including bees and wasps that are captured on wing.  Robber Flies are amazing hunters.  They do not sting.  They will not attack you and bite you, but they might bite you if you tried to pick one up, though we could not imagine how you would ever be able to catch one.  We cannot, based on your photo, determine if this is a Bee Killer in the genus Mallophora, or a Bee-Like Robber Fly in the genus Laphria.  One of the ways they can be distinguished from one another is the shape of the antennae.  Your specimen appears to have antennae that end in fine filaments, a sign it is a Mallophora, however, upon enlarging the photo to better examine the details, your photo is not of high enough resolution to maintain image quality.  Your individual does not have markings similar to any of the five species represented on BugGuide, which makes us wonder if it might not be a Laphria, and based on the photos posted to BugGuide, there are several species with markings similar to your individual.  They seem to all have yellow beards, and it is not possible to make out the beard on your Robber Fly, though we are not sure if the black hairs are lost in the shadow or if the tasty Honey Bee meal is obscuring the beard.

TO BE CONTINUED …

August 3, 2011
Hi again Jessica,
We are positively enthralled by the way you set the tone for your question by providing us with your bug friendly qualifications.  We would like to take additional time to comment on your mention of Cicada Killers.  We have devoted considerable internet real estate on our site toward lobbying for the preservation of Cicada Killers, and when we receive post-mortem images of them, we tag them as unnecessary carnage, but the fact of the matter is that we have never had to share our homes and yards with them.  We really cannot claim to have experienced first hand the communal nesting habits of these large wasps.  We applaud you for your tolerance and also for inquiring about this Robber Fly.  Since we began working on this posting, we have received another unidentifiable image of a large Robber Fly feeding on a Japanese Beetle, and the person who submitted that image wants to know how to encourage more of them.  These large Robber Flies are reported to be able to consume large quantities of Honey Bees, and for that reason, they have a bad reputation among bee keepers.  Thanks again for your wonderful submission.  

Thank you so much for the information. We try not to have knee jerk reactions to what we find in the yard and as the cicada killers are nonaggressive unless you happen to be a cicada, there was no reason to destroy their habitat. It’s a short two month inconvenience of my daughters running to the door from the driveway while screaming.
As for the robber flies, they may be a bit of a bother as we are beekeepers. We have already lost one hive to varroa mites a couple of years ago and would rather not lose another one. Now that I think about it, we have spotted a few smaller species of robber flies in our yard. We have never had these insects in our yard before. Do you think the beehive may be attracting them? Is there any way to humanely deter them from eating my bees?

Hi again Jessica,
We have no advice regarding the deterring of Robber Flies.  The smaller Robber Flies are most likely not preying on your bees, and the larger Robber Flies will not enter the hive.  They will attack individual bees that are in flight.  Good Luck.

Letter 48 – Robber Fly eats Japanese Beetle

 

Japanese beetle eater
Location: Wakefield, RI near Providence, RI
August 2, 2011 5:45 pm
This large bug (over 1”) was seen sitting in our vegetable garden. It snatched a Japanese beetle from the air as it flew by, sucked the juice out of it, and then grabbed another! Awesome!!
What is it and how can we get more?
Signature: Ann in RI

Hi Ann,
There is not enough detail in your photo to determine a genus or species, but this adept predator is a Robber Fly, probably in the genera Laphria or Mallophora.  We just posted a higher quality image of a similar Robber Fly eating a Bee, and there was not enough detail to determine an identity, but you may read our rationale here.  What we especially love about your letter is the fact that the prey is the invasive exotic Japanese Beetle, the scourge of many a gardener. 

Thanks so much for your quick reply and helpful information, Daniel.  We’ll try to get a better photo and maybe we can key it out ourselves!
Your website is really fun and informative.
Thanks again,
Ann in RI

Letter 49 – Robber Fly eats House Fly

 

What’s this fly? It looks mean
Location: Janesville, IA
August 12, 2011 12:20 pm
This fly was outside on my porch. I initially took a series of pictures and it was just the fly. When I returned, it looked like it had caught a house fly and was consuming it. It’s big, about an inch long. It looks like a cross between a fly and a cricket. I really need to buy an insect book.
Thanks.
Signature: Jill Lockey

Hi Jill,
The predator in your photo is a Robber Fly.  Robber Flies are adept at capturing prey on the wing.  If you want an excellent identification guide, consider Eric Eaton’s Kaufman Field Guide to Insects of North America, and Daniel is very proud of his first book, a pop culture tome on insects entitled The Curious World of Bugs.  We can’t believe we don’t have a House Fly category, and now is an excellent time to remedy that.

Thanks for the ID and the suggestions on bug books. I will check those out.
JILL

Letter 50 – Giant Robber Fly Eats Wasp

 

Food chain
Location: southern indiana
November 21, 2011 7:07 am
Robber fly kills & eats wasp
Signature: brian

Hi Brian,
Your Robber Fly appears to be one of the Giant Robber Flies in the genus Promachus.  BugGuide indicates “Adults predatory, often on Hymenoptera,” and your individual is fulfilling its reputation.  The wasp appears to be a Paper Wasp.

Letter 51 – Robber Fly eats Crane Fly in Japan

 

Subject: Love or Death? (mosquitos?)
Location: West Tokyo, Japan (open park)
May 19, 2012 6:28 am
I was out doing more photography in Tokyo and spotted this amazing coupling of, I think, a male and female mosquito. Can you help me determine what sort of bugs these are, and whether one was mating with the other, or just lugging around its corpse!?
(They were atop a leaf at first, then when I got too close they shifted over over to perch in a vertical posture… but I didn’t see any motion from the ”bottom”…)
Thanks and best!
Signature: R Fillingham

Our automated response
Thank you for submitting your identification request.
Please understand that we have a very small staff that does this as a labor of love. We cannot answer all submissions (not by a long shot). But we’ll do the best we can!

Hiya, autobot!
I feel a bit silly even asking, since it seems quite obvious the other insect is dead from its leg position… but then I used that as a clue. Could it be one of those flies that offers a corpse up during mating season as a present to its lover? He’s all stocked up. 🙂
Thanks and best,
R

Dear R Fillingham,
The predator is a Robber Fly and the prey is a Crane Fly.

Hiya Mr Marlos,
Thank you so much! I’ve been on a photo kick focusing on insects around the city parks but have been hopeless about identification.
Here’s a slightly cleaned up shot from the same series, for interest:
You will probably hear from me again soon! Thanks so much again.
Best,
R

Letter 52 – Action Photo: Hanging Thief eats Wasp!!!

 

Subject: Giant Ichneumon?
Location: Columbia, Maryland
August 2, 2012 3:48 pm
This bug rose helicopter-like up from the darkness of my garden weeds, leveled off, and flew away with it’s victim. An assassin bug? Looks like some pictures you have of an Ichneumon.
Signature: Linda

Hi Linda,
This is sure an impressive action photo.  The predator is a Robber Fly in the genus Diogmites, a group commonly called Hanging Thieves.  The prey is some species of wasp.  Hanging Thieves get their common name from their habit of feeding on prey while hanging from a single leg.

Hi,
Thank you so much for such an instant response!
I like to take pictures of butterflies and occasionally “bugs.”  I just wish i had had the presence of mind to switch to video or off my macro setting to auto focus sports on my camera.  But at least I got one shot in focus.
Linda

Letter 53 – Carpenter Bee Robber Fly from South Africa eats Wasp

 

Subject: carpenter fly comment..
Location: Johannesburg, South Africa
September 22, 2012 9:23 am
I did leave a comment, but was unable to load my pics I took with my mobile. So just want to add them here if you might want them:-)
Rob
Signature: rob

Hi Rob,
We first posted a photo that we identified as  Carpenter Bee Robber Fly, Hyperechia marshalli, earlier this year.  Global Species has a matching image.  Your image is a great addition to our Food Chain tag.

Hello Daniel
Thank you very much for your quick reply.. I think you will be getting many mails from me.. you guys are great:-)

Please include South Africa in your subject lines Rob.  That will help get our attention.

Letter 54 – Robber Fly eats Japanese Beetle

 

Subject: killer fly
Location: northern mi
June 21, 2013 8:32 am
I thinkthisis a killer fly eating a rosebug. I have never seen one with yellow . Thanks for your time
Jeffrey Pomeroy
Signature: jeffrey pomeroy

Dear Jeffrey,
The predator in your photo is a Robber Fly and many species of Robber Flies are black and yellow, which makes them effective mimics of Bumble Bees.  The prey in your photo is the invasive, exotic Japanese Beetle which does feed on roses.  When they are plentiful, Japanese Beetles can do major damage to foliage and blossoms of roses and hundreds of other ornamental and garden plants.  Our mother who is an avid gardener refers to the damage caused by Japanese Beetles as “lace doilies” because of the numerous holes in leaves which causes them to resemble lace when only the veins remain.

Letter 55 – Bee-Like Robber Fly eats Big Legged Plant Bug

 

Subject: Bee mimic?
Location: Powell County, KY
July 9, 2013 7:06 pm
I took this photo today while creek walking on our property in Powell County KY. I thought it was really strange a bumble bee would be attacking another bug! Then I just thought it was the strangest bumble bee ever. Once I cropped the photos and brightened the fill light to allow more detail to be seen, I don’t think this is a bumble bee! It is one mean looking dude, I’m glad these don’t come in football size!
I appreciate your help in identifying this bug!
Signature: Sandra

Dear Sandra,
The predator in your photos is a Bee Like Robber Fly in the genus Laphria, possibly Laphria grossa.  See BugGuide for more information.  The prey is a Big Legged Plant Bug in the genus Acanthocephala, and again, more information is available on BugGuide.

Letter 56 – Robber Fly preys upon Blow Fly

 

Subject: Creepy Fly Eating Bug??
Location: Backyard of home in Antelope Valley, CA
July 14, 2013 6:05 pm
This is the second day I have seen this bug and finally got a good picture! I live in the High Desert of Antelope Valley, CA. and have never seen it before. Did not realize it was eating a fly until I loaded the picture and wow…..CREEPY!
Signature: CheckingOutBugs

Dear CheckingOutBugs,
The predator is some species of Robber Fly and the appears to be a Blow Fly.

Letter 57 – Robber Fly with Prey

 

Subject: Blue-eyed Robber Fly (Megaphorus megachile?)
Location: Yallowstone National Park, Wyoming
August 17, 2013 3:14 pm
Hi Daniel!
Just back from Yellowstone/Grand Teton – a spectacular vacation. I saw lots of beautiful winged creatures, but this little blue-eyed fly caught my attention. I am pretty sure it’s a robber fly, and I am pretty sure it’s clutching some prey. I apologize for the bad photo, but it let me get one shot from a distance before it took off. I hope all is well with you!
Signature: Dori Eldridge

Hi Dori,
We cannot say for certain which species of Robber Fly you have photographed, however we do agree that based on images posted to BugGuide, this looks very similar to the members of the genus Megaphorus.

Letter 58 – Carpenter Bee Robber Fly eats Honey Bee in South Africa

 

Subject: Carpenter Bee Robber Fly
Location: Johannesburg South Africa
November 21, 2013 2:47 am
I took these yesterday in my drive way.
Signature: Tiaan

Hi Tiaan,
Thanks for sending us your photos of a Carpenter Bee Robber Fly, Hyperechia marshalli, feeding on a Honey Bee.  They are a nice addition to our Food Chain tag.

Letter 59 – Robber Fly eats Bee in Australia

 

Subject: Identification of a bug / insect
Location: HMAS Cerberus, Hastings, Victoria
January 22, 2014 12:59 pm
Hi,
Hoping you can help me please.
I was at HMAS Cerberus earlier this week. I had asked my son to stand next to a monument for a photo. He spotted a bee and said “I’m not standing there, I don’t want to get stung” .. then out of nowhere, this huge bug / insect came flying past me, picked the bee out of the air and landed on the monument …. I told Jordan he didn’t have to worry about the bee anymore! hahaha
But taking photos of the insect, I have never seen one before and would like to find out what it is if possible. It’s an amazing looking bug. The feet on it look like hooves! Please see attached photos.
Thanks and kind regards,
Jen.
Melbourne, Australia
Signature: Jen – Jen’s Freelance Photography

Hi Jen,
What an amusing anecdote you have provided.  Did Jordan worry about this considerably larger, predatory Robber Fly in the family Asilidae?  Based on photos on the Brisbane Insect website, we believe this might be a Common Brown Robber Fly in the genus Zosteria.  Robber Flies are very adept hunters and they often take large prey, including bees and wasps, while on the wing, just as you witnessed.

Hi Daniel,
Thanks so much for your reply.
Funnily enough, Jordan wasn’t as worried about the much larger “Robber Fly”.  It looked somewhat like a dragon fly and didn’t have a stinger on it’s tail so we were both thinking at the time that it was relatively harmless (until I read up on them!).  Seeing it take the bee mid flight, hearing an almost “thud” as it landed and then watching it devour it’s prey should have been a hint, in heinsight, that this was not a particularly friendly creature …. hahahaha.
I had sent an email to yourselves and also Pestworld.org   …  the people at Pestworld.org loved my images so much that they will now be using them on their website for identification purposes, which is fantastic.
Thanks so much for taking the time to get back to me.  Should I encounter any further strange little creatures in my travels, I will forward them on.
Thanks and kind regards,
Jen.
Jeannie Van Den Boogaard
Jen’s Freelance Photography

Hi again Jen,
For the record, Robber Flies do not prey upon people and we have never gotten a report from a person who was bitten by a Robber Fly.  We suspect that if a Robber Fly is captured in one’s hands, a bite might result.

Letter 60 – Bee-Like Robber Fly eats Longicorn in Texas

 

Subject: Help Id?
Location: Big thicket tx
May 16, 2014 8:28 pm
These 2 pics were taken in early May in Big Thicket National Preserve.
Some type of robber fly or canibal fly I guess but can’t find anything like it online.Can you help Id it? Oh. What is it eating? I haven’t seen anything like that either.
Thanks
Signature: Anonymous

Dear Anonymous,
We have taken the liberty of lightening your Food Chain image of a Robber Fly eating a Longicorn Beetle.  We need to do some research to identify both beyond the family level, and that is our next task.  We are relatively certain this is a Bee-Like Robber Fly in the genus Laphria, and the closest match we could find on BugGuide is Laphria grossa, though BugGuide does not have any records from Texas.  Since Big Thickets is in the eastern portion of Texas, we believe there is a strong possibility that our identification is correct.  We have based our potential identification on the black legs and the markings on the abdomen.  A similar looking species, Laphria vorax, has more yellow hairs on the legs according to images posted to BugGuide.  Now that we have provided an identification, at least to the genus level, of the predator, we can turn our attention to the Longicorn, a Borer Beetle in the family Cerambycidae that has many members that mimic wasps, including the prey in your image.  The closest match we could find on BugGuide is Clytus marginicollis, but again, there are no reports on BugGuide from Texas.  The antennae on your beetle are longer than the examples on Bugguide of Clytus marginicollis, so we are not as confident with our identification of the prey as we are with our identification of the predator.  A dorsal view of the prey would be helpful.  Perhaps one of our readers will write in with some suggestions.

I only have 1 other shot of the prey from the same angle though it is lighter since I was bracketing 1 stop for scenery and potential HDR images.
There are better exposed images but they are blurry.
thanks

 

Letter 61 – Robber Fly eats Bee

 

Subject: Strange big eyed bee eating bug
Location: Bellflower, Ca
August 4, 2014 10:43 am
Hello Bugman,
Monday, August 4, 2014. My daughter saw this strange bug on our tomato cage. When I went to take its picture, I saw that it had a bee in its legs. The bee was upside down and looked dead. We think it was eating the bee.
This bug had what looked like brown wings and huge eyes. Please help identify this strange big eyed bee eating bug.
Thank you
Signature: Deana Campbell

Hi Deana,
This is some species of Robber Fly in the family Asilidae, but there is not enough detail in the image to make a more specific identification, but we suspect it is a Bee Killer, Mallophora fautrix.

Thank you for your quick response. I looked up Robber Fly on the What’s That Bug page and did find pics that looked just like the bug on my tomato cage.
Thanks again,
Deana Campbell

Letter 62 – Robber Fly eats Cicada

 

Subject: Big fly?
Location: corinth, tx
August 12, 2014 6:23 pm
I was . walking the dog and solve this bug eating a cicada.it looked like it was about one and a half to 2 inches long. I have never seen one and I wanted to know what it was.
Signature: Larry L.

Dear Larry,
This is some species of Robber Fly in the family Asilidae, and it is not a species we immediately recognize, so we are going to have to research its identity.  It is indeed eating a Cicada.  Robber Flies are highly specialized predators that are very adept at taking large prey on the wing.  Texas and Arizona both have unusual, not commonly seen Robber Flies that are not found elsewhere in the U.S., though the ranges of those species frequently extend into Mexico.  We believe that based on this image from BugGuide, it may be Microstylum morosum.  According to Beetles in the Bush, this is “North America’s largest robber fly” and “Until recently, Microstylum morosum was considered a Texas-endemic.  However, Beckemeyer and Carlton (2000) documented this species to be much more broadly distributed in the southern Great Plains (from Texas up into Oklahoma and Kansas and west into New Mexico, Arizona, and Colorado), and Warriner (2004) recorded it shortly afterwards in Arkansas.”  We wrote to Eric Eaton to see if he agrees with our identification.

Eric Eaton concurs
I would agree.  Seems to be a pretty distinctive species.
Eric

Letter 63 – Robber Fly eats Honey Bee

 

Subject: Dragonfly eating a bee?
Location: Austin, tx
August 16, 2014 8:49 pm
Hi Bugman!
Found this dragonfly looking insect sucking down a bee in my back yard. Is it a dragonfly? It was definitely drinking the bee. Craziest thing. I have a giant oregano patch bit flower right now and the bees love it. We have a pool so sometimes see dragonflies, but this had some odd features I’d never seen on a dragonfly, like a clear abdomen and a feathery black tuft at the end of his backside. What’s that bug?
Laura
Austin, TX
Signature: Laura

Hi Laura,
You are mistaken in thinking that this is a Dragonfly, though like a Dragonfly, this Robber Fly is an adept predator capable of capturing large prey on the wing.  We believe we have correctly identified your Robber Fly as a member of the genus Efferia due to its resemblance to many members in the genus, including this unidentified species that is pictured on BugGuide.  According to BugGuide, there are “110 spp. in our area” and “in our area, the vast majority are restricted to sw. US, with some widely western spp. and just two widespread spp..”  We interpret that to mean that many species are very limited in their distribution.  Alas, we haven’t the necessary skills to attempt a species identification.

Letter 64 – Giant Robber Fly eats Honey Bee

 

Subject: Predatory bee killer!
Location: Tucson, AZ
August 20, 2014 5:39 pm
This enormous predator buzzed down to enjoy its dinner on an elk antler in my yard – what is it?
Signature: Alicia

Dear Alicia,
This is one of the best feeding Robber Fly images we have received all summer.  This is a Giant Robber Fly in the genus Promachus, a genus well populated in our archives this season due to all the images we have received of Red Footed Cannibalflies.  This is a different member of the genus, and we believe it is Promachus albifacies, a species with no unique common name.  You can compare your individual to this image on BugGuide.

Letter 65 – Bee-Like Robber Fly eats Yellowjacket in Western Canada

 

Subject: Large insect with wasp prey
Location: West coast of British Columbia
July 29, 2015 3:43 pm
I took these photos on July 29/15 in the town of Nanaimo, on the west coast of British Columbia. This awesome creature was on a salal leaf, in a dry forest of Douglas fir, hemlock, and arbutus. I wanted to get a side view shot as well, but it must have been bothered by my intrusion into its juicy meal, and flew away. Can you tell what species it is? I think I’ve narrowed it down to the Laphria genus, Robber flies.
Thanks a lot. Love your site!
Signature: John Segal

Dear John,
Because of the thick antennae that helps to identify the genus, we agree that this is a Bee-Like Robber Fly in the genus Laphria, and after searching through 10 pages of species on BugGuide, we have narrowed down the possibilities to five species that have yellow thoracic hair and that generally resemble your individual, which appears to be feeding on a Yellowjacket based on this facial closeup on BugGuide.    The abdomen on Laphria fernaldi appears too orange to be your species.  In alphabetical order, the most similar looking species on BugGuide are:  Laphria astur,  Laphria janus, Laphria partitor and Laphria unicolor.  Of those, we believe the images of Laphria astur on BugGuide look the closest, but we are by no means experts in the identification of Robber Flies.  Thanks for your excellent Food Chain contribution, and in the future, we can accept larger digital files to ensure the highest quality of the images on our site.

Hi Daniel,
Thanks very much for helping me identify an insect I’ve never seen before.  I really appreciate it.
Those photos are about 650 X 450 KB; the size I use for email. Let me know if you’d like me to send them again, as larger files, and what the maximum size is that you can receive.
Thanks again.  Excellent website you have there!
John

Hi John,
We can easily accept 5MB files.  We are then able to crop into details like the antennae on this Bee-Like Robber Fly.  You may send them larger and we will crop to some details.

Hi Daniel,
Great! Okay, here are my two photos, each about 1.7 MB.
Thanks again for your great website, and all the work you do for us bug-curious types!
John

Thanks for sending the higher resolution files.  Since you already cropped the images the first time, we were not able to magnify much more, but we did move a bit closer.

Letter 66 – Robber Fly with Prey in Croatia

 

Subject: Cannibalfly?
Location: Split, Croatia
August 9, 2015 1:51 pm
Hi, I took this picture today on my balcony. I live in Split, Croatia. What kind of bug is that (tha one that eats) and is it normal to meet it in this area? Thank you!
Signature: Irena

Dear Irena,
The predator in your image is a Robber Fly in the family Asilidae.  We are uncertain of the species, or if it is native to Croatia, but this posting on Diptera Info indicates that members of the family are found in Croatia.

Letter 67 – Robber Fly eats Fly

 

Subject: Robber Fly, perhaps, with Prey, maybe?
Location: Coryell County, TX
April 6, 2016 12:05 am
Hello! This insect flew out of a rose bush and landed on the fence, holding prey, maybe? I found this on Bug Guide, but don’t know if it is the same. http://bugguide.net/node/view/5188
Clear skies, 80 degrees this afternoon.
Thank you and best wishes!
Signature: Ellen

Dear Ellen,
We always look forward to your submissions.  We agree with your assessment that this is a Robber Fly in the genus Efferia.  The tuft on the tip of the abdomen indicates this is a male Robber Fly.  The prey is also a fly in the order Diptera, but we are not sure of its classification.

Letter 68 – Hanging Thief eats Wasp

 

Subject: What killed this wasp!?
Location: Cincinnati
July 18, 2016 3:24 pm
The other day my girlfriend saw this larger mosquito looking thing on her chair. And then today we saw it take down a full grown wasp! We want to know if we have been brought a savior, or will it kill my family in my sleep?
Signature: Billy Yeager

Dear Billy,
The predator in your image is a Hanging Thief, a Robber Fly in the genus Diogmites, and it is easy to see where they got their common name by looking at your image.  Thief is a synonym for the family name Robber and the members of the genus Diogmites frequently feed while hanging from a single front leg.  Large Robber Flies are impressive predators that hunt on the wing, and BugGuide describes the diet of the Hanging Thieves as eating “insects (often larger than themselves), mostly aculeate Hymenoptera, but also Odonata and Diptera (incl. members of the same species).”  The stinging insects in the order Hanging Thieves feed upon include wasps as in your image and bees. 

Letter 69 – Robber Fly eats Blow Fly

 

Subject: Flying fly eater
Location: Central Connecticut
August 1, 2016 10:42 am
Saw this guy on a fencepost in central Connecticut. Curious about the ID. Thanks
Signature: Bug watcher

Dear Bug Watcher,
The predator in your image is a Robber Fly, but we are not certain of the genus.  We will attempt to research its identity further.  The prey appears to be a Blow Fly, perhaps a Green Bottle Fly or some other member of the genus Lucilia, a group that is well documented on BugGuide.

Letter 70 – Robber Fly Eats Bee

 

Subject: weird bug mating with bee
Location: high point, north carolina
August 15, 2016 5:26 pm
so i was sitting in my room and i looked on the screen of my window and saw a large-ish bug mating with a bee (bumble bee i think). the bee was “on bottom” and the larger bug was on top. the large bug had wings and large bulge-y black eyes. it seemed as if the wings went into a point at the bottom so it appeared somewhat in a triangle shape. i don’t know if that type of bug and bees mate often but the mating thing might help.
Signature: -brit

Dear -brit,
Bees and other insects do not engage in interspecies mating.  Your image is not ideal for identification purposes, but we believe you have observed a Robber Fly eating a Bee.  Large Robber Flies often prey upon wasps and bees.

Letter 71 – Carpenter Bee Robber Fly from South Africa eats Wasp

 

Subject: Robber Fly
Location: Brackenfell, Western Cape
April 6, 2017 12:28 am
Saw it in our garden during Desember 2016 in Brackenfell, Western Cape. Have never seen it before and I have been living here many years. Are they found all over South Africa?
regards
Signature: Jackie

Dear Jackie,
This Carpenter Bee Robber Fly, Hyperechia marshalli, feeding on what appears to be a Paper Wasp is a marvelous addition to our Food Chain page.  We are not certain of the exact extent of its range in South Africa, but in our own archives, we have gotten reports from Johannesburg and Gauteng as well as Tanzania.

Letter 72 – Robber Fly eats Insidious Flower Bug

 

Subject: Wasp?
Location: Southwestern Ontario, Canada
June 24, 2017 9:46 am
I’ve photographed a few of these small (1 cm) wasps(?) with a blue patch between the eyes. I’m uploading a shot of one eating an Orius insidiosus (I think).
Signature: Jim Elve

Dear Jim,
Your image is gorgeous and quite detailed.  This is not a Wasp.  It is a Robber Fly (see BugGuide) in the family Asilidae, and we generally only attempt to identify large Robber Flies to the species level as so many smaller species look quite similar.  We agree that the prey is an Insidious Flower Bug based on BugGuide where it states:  “important predator of phytophagous mites and mite eggs, insect eggs, soft-bodied insects”.

Letter 73 – Robber Fly with Prey

 

Subject: Any ideas?
Location: Michigan
July 2, 2017 10:56 am
This bug was on my deck. I live in Michigan. Does anyone know what it is?
Signature: Thank you! Christie Haines

Dear Christie,
This is a predatory Robber Fly, probably a member of the genus Promachus, a group whose members are called Giant Robber Flies or Bee Killers according to BugGuide.  It might be Promachus bastardii based on BugGuide images.

Letter 74 – Gems From Our Archives: Bug of the Month #2 August 2011: RARE Bee Killing Robber Fly eats Honey Bee

 

Six Years ago today we originally posted this exciting submission.

Ed. Note:  February 21, 2014
It has just come to our attention that this is one of the rarest North American Robber Flies, Dasylechia atrox, and more information can be found on BugGuide.

Carnivorous bumble bee?
Location: Royal Oak, MI
August 2, 2011 2:15 pm
We have a honey bee hive in our yard and have been very bug friendly. We have cicada killing wasps in our driveway and we just steer clear of them instead of filling it with concrete.
Imagine my shock when I was hanging laundry out and saw one of our honey bees having the life drained out of it by what appears to be a bumble bee. Is it?
Signature: Jessica

Hi Jessica,
We absolutely love your email, and we would like to wax poetically after we answer your question.  This is a Robber Fly.  It is one of two genera that both feed on large flying insects including bees and wasps that are captured on wing.  Robber Flies are amazing hunters.  They do not sting.  They will not attack you and bite you, but they might bite you if you tried to pick one up, though we could not imagine how you would ever be able to catch one.  We cannot, based on your photo, determine if this is a Bee Killer in the genus Mallophora, or a Bee-Like Robber Fly in the genus Laphria.  One of the ways they can be distinguished from one another is the shape of the antennae.  Your specimen appears to have antennae that end in fine filaments, a sign it is a Mallophora, however, upon enlarging the photo to better examine the details, your photo is not of high enough resolution to maintain image quality.  Your individual does not have markings similar to any of the five species represented on BugGuide, which makes us wonder if it might not be a Laphria, and based on the photos posted to BugGuide, there are several species with markings similar to your individual.  They seem to all have yellow beards, and it is not possible to make out the beard on your Robber Fly, though we are not sure if the black hairs are lost in the shadow or if the tasty Honey Bee meal is obscuring the beard.

TO BE CONTINUED …

August 3, 2011
Hi again Jessica,
We are positively enthralled by the way you set the tone for your question by providing us with your bug friendly qualifications.  We would like to take additional time to comment on your mention of Cicada Killers.  We have devoted considerable internet real estate on our site toward lobbying for the preservation of Cicada Killers, and when we receive post-mortem images of them, we tag them as unnecessary carnage, but the fact of the matter is that we have never had to share our homes and yards with them.  We really cannot claim to have experienced first hand the communal nesting habits of these large wasps.  We applaud you for your tolerance and also for inquiring about this Robber Fly.  Since we began working on this posting, we have received another unidentifiable image of a large Robber Fly feeding on a Japanese Beetle, and the person who submitted that image wants to know how to encourage more of them.  These large Robber Flies are reported to be able to consume large quantities of Honey Bees, and for that reason, they have a bad reputation among bee keepers.  Thanks again for your wonderful submission.  

Thank you so much for the information. We try not to have knee jerk reactions to what we find in the yard and as the cicada killers are nonaggressive unless you happen to be a cicada, there was no reason to destroy their habitat. It’s a short two month inconvenience of my daughters running to the door from the driveway while screaming.
As for the robber flies, they may be a bit of a bother as we are beekeepers. We have already lost one hive to varroa mites a couple of years ago and would rather not lose another one. Now that I think about it, we have spotted a few smaller species of robber flies in our yard. We have never had these insects in our yard before. Do you think the beehive may be attracting them? Is there any way to humanely deter them from eating my bees?

Hi again Jessica,
We have no advice regarding the deterring of Robber Flies.  The smaller Robber Flies are most likely not preying on your bees, and the larger Robber Flies will not enter the hive.  They will attack individual bees that are in flight.  Good Luck.

Letter 75 – Robber Fly preys upon Fly

 

Subject:  Odd fly eating another fly
Geographic location of the bug:  Columbus Ohio
Date: 07/12/2018
Time: 05:07 PM EDT
Your letter to the bugman:  Found this cool guy on my trash bin with another smaller fly in its mouth. It also had a long stinger/appendage coming out of its bottom.  It was not afraid of me and simply wanted to finish its meal
How you want your letter signed:  Katy

Dear Katy,
The predator is a Robber Fly in the family Asilidae, but we are uncertain of the species.  Robber Flies are amazing predators that capture prey while flying.

Letter 76 – Large Robber Fly eats Whitespotted Sawyer in British Columbia

 

Subject:  2 bugs: fighting or mating?
Geographic location of the bug:  Kootenays, British Columbia, Canada
Date: 08/04/2018
Time: 12:51 PM EDT
Your letter to the bugman:  I was out camping and the hairy looking bug on top aggressively latched onto the one with long antennae. Just wondering what they are, and what was going on? Is the hairy one eating the other one? Are they male and female of the same species and they’re mating? (seems unlikely, they look so different) Thank you for your help!
How you want your letter signed:  Jesse

Dear Jesse,
Your images are awesome, but we wish there was more detail in the image to help us identify the predator, because this is most definitely NOT mating.  The prey is a Whitespotted Sawyer, Monochamus scutellatus (see BugGuide), and the predator is a large Robber Fly, but we are not certain of the species.  It does not look like any of the Robber Flies in the family Asilidae pictured on the Royal British Columbia Museum.  Large Robber Flies often take down considerably larger prey that they capture while flying.

Letter 77 – Robber Fly with Prey

 

Subject:  Cannibal fly?
Geographic location of the bug:  Hudson River Valley, New York
Date: 08/26/2018
Time: 07:33 PM EDT
Your letter to the bugman:  Hello. I took this picture just hoping to get an up close pic of what I thought was some sort of horsefly. I zoomed in to find he was eating a smaller fly. He flew away with the fly right after I took the picture . Just wondering what it is . Thank you.
How you want your letter signed:  Thank you, Sanders Trippe

Dear Sanders,
This is a Robber Fly with its Dipteran prey, but the dark color leads us to believe it is not a Red Footed Cannibalfly.

Letter 78 – Carpenter Bee Robber Fly eats Wasp in South Africa

 

Subject:  Carpenter bug?
Geographic location of the bug:  Bluff Durban South Africa
Date: 02/20/2019
Time: 06:08 AM EDT
Your letter to the bugman:  Is this a carpenter bug? 2nd time submitting first  gave me an error just incase you get twice
How you want your letter signed:  Charlene Boock

Dear Charlene,
Your Food Chain image is magnificent.  Thanks for taking the time to ensure it was properly submitted.  It does appear to be a Carpenter Bee Robber Fly and the prey appears to be a Paper Wasp.

Letter 79 – Beelike Robber Fly eats Japanese Beetle

 

Subject:  Super Close ups of Robber Fly
Geographic location of the bug:  Ellijay, GA
Date: 06/11/2019
Time: 08:23 AM EDT
Your letter to the bugman:  My son excitedly for this guy and we Scored some great shots of this guy June 10, 2019.  He didn’t seem to mind that I was interrupting his dinner. Would love to know the species.
Enjoy!
How you want your letter signed:  Melissa

Dear Melissa,
Your son’s images are wonderful and an excellent addition to our Food Chain tag.  This is a Beelike Robber Fly in the genus Laphria, and it is feeding on an invasive, exotic Japanese Beetle, the scourge of many gardeners.  Because of the yellow hairs on the abdomen and legs, and because of your location, we believe this is Laphria macquarti based on this BugGuide image.  According to BugGuide:  “Seems to prefer small beetles, but would eat other insects, even other robber flies” which further supports our tentative identification.

Letter 80 – Robber Fly eats Sawyer

 

Subject:  Bee cricket situation?
Geographic location of the bug:  Lake George NY
Date: 07/01/2019
Time: 08:27 PM EDT
Your letter to the bugman:  So we saw this scenario while on vacation in ny. I guess I just really want to know what’s going on here. It looks almost like they’re trying to mate, which is obviously not the case. I thought the bug underneath was a cricket, but I’m not positive. Anyway, they were on a busy stairwell, so I tried to move them out of the way with my room card. When I touched them, the bee LIFTED the cricket and started flying! They dropped a second later, but the bee lifted his (victim?) as high as my head. I was just wondering if anyone there might know what’s going on. I didn’t think bees attacked other insects like this. I LOVE your site btw and have to tell you that you are the reason I’ve gone from being terrified of insects, to now thinking they’re adorable and picking them up!
Thanks!
How you want your letter signed:  KBH

Dear KBH,
Thanks for your kind words, and we are happy to learn our site has helped to alleviate your fear of many insects, though we caution you that many insects should not be handled due to the possibility of stings, bites, urticating hairs and chemical defenses that can cause skin reactions.  We are thrilled with your dramatic Food Chain images, but your speculation about this being a Cricket and a Bee is quite wrong.  Though not a Bee, the predator is a Bee-Like Robber Fly in the genus Laphria, and we felt up to the challenge of providing you with a species identification.  The most frontal facing of your images shows the beard hair as well as the markings on the abdomen and the leg hairs, so we are very confident that your Bee-Like Robber Fly is Laphria thoracica which is pictured on BugGuide.  According to Wisconsin Butterflies:  “This species has a mainly black mystax with some scattered yellow hairs, and mainly black hairs surrounding the eyes. The thorax is yellow and the abdomen may have a variable amount of yellow hairs on abdominal segments two through four. The yellowish arc of hairs that extend from the anterior of the thorax to below the wing insert, make an obvious field mark that is useful in the field.”  The lateral view you provided shows the “yellowish arc of hairs that extend from the anterior of the thorax to below the wing insert” confirming the species identification.  Large Robber Flies are among the greatest aerial insect predators, and they frequently capture prey on the wing, including insects many times their size.  The prey appears to be a Sawyer Beetle similar to this White Spotted Sawyer pictured on BugGuide.

Letter 81 – Robber Fly eats Bumble Bee in Croatia

 

Subject:  Robbery fly
Geographic location of the bug:  location: GPS@43°47’39″N 15°40’51″E (19.0 m)
Date: 07/18/2019
Time: 03:29 PM EDT
Your letter to the bugman:  This about 3 cm bug was sucking a brombee in my garden. I have s lot if brombees in my lavender and ‘stockroses’. It had yellow-black legs with hairs. Long body with yellow-brown stripes and very long brownies wings folded onbthe back.
How you want your letter signed:  Wilma

Dear Wilma,
Based on the GPS coordinates your provided, Google Maps places this sighting in Croatia.  When we searched the internet for Croatian Robber Flies, we located this FlickR posting of Pogonosoma maroccanum which appears very similar to your individual.

Letter 82 – Hanging Thief eats Wasp while hanging

 

Subject:  Robber Fly
Geographic location of the bug:  Cleveland, NY 13042
Date: 08/08/2019
Time: 09:59 PM EDT
Your letter to the bugman:  Hi Mr. Bugman  – I came across this insect while photographing dragonflies in my small meadow of grasses and wildflowers. I heard him before I saw him. I was quite fascinated with how low and slow he flew and how loud he was! Sounded like a small drone! I noticed him first yesterday but all he did was fly back and forth without ever stopping. Then late this morning he was in the dirt on the edge of the little meadow acting like an ovipositing dragonfly, but in one place. Then this afternoon I saw him/her fly across the meadow and land quite close by. That is when I got the photos. Any ID help you can give me would be most appreciated.
How you want your letter signed:  Ginny

Dear Ginny,
This magnificent Robber Fly in the genus Diogmites is a Hanging Thief, and it is eating its prey, a Wasp, in the typical manner which has led to its common name, by hanging from one leg.  We rarely try to identify Hanging Thieves to the species level as we don’t have the necessary expertise, but this sure looks to us like Diogmites discolor which is pictured on BugGuide.  You might have witnessed oviposition, because according to BugGuide:  “Oviposits in ground, and ovipositor equipped with spines to aid in covering eggs. Larvae are possibly predators in soil”

Letter 83 – Robber Fly eats Honey Bee in Italy

 

Subject:  Unidentified predatory insect Italy
Geographic location of the bug:  Abruzzo Italy
Date: 07/04/2021
Time: 12:01 PM EDT
Your letter to the bugman:  Hello, can you help me identify this obviously predatory insect which appears to be feeding on a bee. The photo was taken 1/7/2021 in Abruzzo Itay. I have shown the photo locally but no-one seems to recognise it.
Many thanks
How you want your letter signed:  J. Seymour

Dear J. Seymour,
This is one impressive Robber Fly in the family Asilidae.  We believe it is Pogonosoma maroccanum which is pictured in our archives.   It is pictured on the Global Biodiversity Information Facility site and on the Smithsonian EOL site.

Letter 84 – Giant Robber Fly drowns in pool, possibly with prey

 

Subject: Type of Robber Fly?
Geographic location of the bug:  Asheville, NC (WNC)
Date: 08/14/2021
Time: 04:58 PM EDT
Your letter to the bugman:  Found this one floating in the kiddie pool. It’s about 2″ long. Can you identify it for me, please and thanks?
How you want your letter signed:  Curious in WNC

Dear Curious in WNC,
This is a Giant Robber Fly in the genus Promachus, and based on images posted to BugGuide, we believe it might be Promachus hinei.  There appears to be a wing near the Giant Robber Flies legs that does not belong to the Giant Robber Fly.  We suspect it might have caught prey just before falling into your pool and drowning.

Letter 85 – Giant Robber Fly Eats Bee

 

Subject:  Identify insect
Geographic location of the bug:  Wareham, Massachusetts
Date: 07/12/2022
Time: 03:00 PM EDT
Your letter to the bugman:  This insect flew down and landed at the side of a trail with what appears to be a bumblebee in its jaws! The month is July and it was in the woods of the Great Neck Conservation Area (Cape Cod).
How you want your letter signed:  Paul Smith

Dear Paul,
This efficient flying predator is a Giant Robber Fly and we believe it is either in the genus Promachus which is represented on BugGuide with 16 species or the genus Proctacanthus which is represented on BugGuide with 15 species. Proctacanthus rufus pictured on BugGuide is one good possibility.  These are among the largest Robber Flies and both genera cited frequently prey on bees and wasps.

 

 

Letter 86 – # 9994: Yellow Bellied Bee Assassin

 

Unknown Colorful Beetle In Arizona
May 13, 2010
I found the following bug crawling on the leaves of a sunflower in my school garden today (May 13, 2010). The bug is red, black and yellow, and I have searched the internet and can’t find it. It had two antenna and what looked like a downward-turned horn (very skinny). It stood still while we took a picture of it, then flew to a nearby tree. The weather was sunny.
Mr. Bane’s Class
Glendale, AZ

Dear Mr. Bane’s Class,
Though it looks like a beetle, this is a True Bug.  Beetles have complete metamorphosis and chewing mouth parts. True Bugs have incomplete metamorphosis and piercing mouth parts.  More specifically, this is an Assassin Bug in the family Reduviidae.  It is known as a Bee Assassin in the genus Apiomeris, and though the under belly is not visible, we believe it to be a Yellow Bellied Bee Assassin, Apiomerus flaviventris which we identified on BugGuide.  Another possibility presented on BugGuide is that this might be a Bee Assassin, Apiomerus spissipes which also lives in Arizona.  We believe it is the former species because of the yellow coloration as the latter appears to have more white in its markings.