Currently viewing the category: "Robber Flies"
What's That Bug? does not endorse extermination

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

Hanging Thief

Hanging Thief

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

What's That Bug? does not endorse extermination

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

Robber Fly feeds upon Blow Fly

Robber Fly feeds upon Blow Fly

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

What's That Bug? does not endorse extermination

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

Bee-Like Robber Fly eats Leaf Footed Bug

Bee-Like Robber Fly eats Big Legged Plant Bug

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.

Bee-Like Robber Fly eats Big Legged Bug

Bee-Like Robber Fly eats Big Legged Plant Bug

What's That Bug? does not endorse extermination

Subject: Modernist Bug
Location: Vail, AZ
July 4, 2013 11:28 am
This is the first of this kind I have noticed. Was photographed on the Arizona Trail near Three Bridges. Landed in front of me like a grasshopper.
Signature: Carl

Robber Fly

Robber Fly

Hi Carl,
This is a Robber Fly and your individual is one impressive looking predator.  We are not certain of the species, but it does resemble members on the genus
Polacantha pictured on BugGuide where the information provided states that Polacantha arctuata is found in Arizona.  All of the photos on BugGuide of the species are males and we cannot locate any photos of females.  We believe your Robber Fly is a female.  We cannot locate any other images of Polacantha arctuata on the internet.  Your individual appears to lack the striped abdomen found on Promachus sackeni which is pictured on BugGuide.  While we cannot be certain of the species, we can tell you that Robber Flies are very adept predators and they often take large winged prey in flight.  Many species feed on large bees and wasps.  Perhaps one of our readers will have better luck with a species identification.

Wow! Thank you!

Eric Eaton Responds to our request
Daniel:
Eric Fisher is the go-to person for robber flies.  I’m sorry, I don’t have his e-mail address in my contact file….
This one appears to be a male in the genus Proctacanthus, if I know anything at all (which is sometimes suspect with asilids!).
Eric 

What's That Bug? does not endorse extermination

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

Robber Fly eats Japanese Beetle

Robber Fly eats Japanese Beetle

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.

What's That Bug? does not endorse extermination

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

Robber Fly

Bee-Like Robber Fly

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

What's That Bug? does not endorse extermination