Currently viewing the category: "Robber Flies"
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

Subject: Some kind of fly?
Location: Lynchburg, VA
May 29, 2013 6:24 pm
Observed this critter in Lynchburg, VA, May 29, about 2:30 pm.
It’s happily devouring something which I think looks a little like a firefly, but not too much of it is left. When I tried to get closer & see whether it has two wings or four, it took off, but I think it’s two. Size: approx 7/8” long.
Some kind of fly?
Signature: Ann Bee Zee

Virginia Bee Killer

Virginia Bee Killer

Dear Ann Bee Zee,
This is a predatory Robber Fly in the genus
Laphria, and we believe it is the Virginia Bee Killer, Laphria virginica.  We compared your photo to images on BugGuide.  These impressive insects often take prey on the wing, and they are often seen preying upon bees and wasps.

What's That Bug? does not endorse extermination

Subject: Robber Fly from Elyria Canyon Park
Location: Elyria Canyon Park, Mount Washington, Los Angeles, CA
April 15, 2013
Yesterday while volunteering in Elyria Canyon Park, I noticed this fly in the tall grass that we were removing as part of brush clearance in the butterfly garden.  I thought it was a Soldier Fly and I asked Becky to take a photo.  I couldn’t find a matching Soldier Fly on BugGuide, so I requested assistance from Eric Eaton.  He quickly responded.

Robber Fly

Robber Fly

Eric Eaton provides an identification
Daniel:
It is a robber fly.  Looks to me like maybe Dioctria for genus, but no Bugguide records from there, so….?
Eric

What's That Bug? does not endorse extermination

Subject: Giant yellow robber fly from Australia?
Location: -36.131866,146.926785
March 10, 2013 7:50 am
Hey there, I found a fly today (deceased) and took a few pictures of it. I was curious as to what the hell it was, so I searched and came up with your site featuring some examples of large flies with a yellow abdomen which looked fairly identical to the one I saw. This particular specimen was found on top of Huons Hill, Wodonga, Victoria, Australia. The large Mitsubishi key you see in a couple of the photos is exactly 92.9mm or 3.657” long.
Sorry about the poor photography, I only had an iphone with me, and couldn’t see the screen to ascertain whether or not it was focusing properly on the fly, which it wasn’t.
Feel free to contact me via email – thesixthwheel@gmail.com
Signature: Cheers, Nick.

Giant Yellow Robber Fly

Giant Yellow Robber Fly

Hi Nick,
We agree that this looks like a Giant Yellow Robber Fly,
 Blepharotes coriarius.  We received a comment on a posting last week and Wolfgang said he would send a photo, so we thought these might be the anticipated images, but we were mistaken unless you also wrote to us under a pen name.  Large Robber Flies are magnificent creatures and your photo of the underside of the body shows the long legs that can be used to snatch prey while in flight.

Giant Yellow Robber Fly

Giant Yellow Robber Fly

More images of the Giant Yellow Robber Fly can be found on the Brisbane Insect website.

Thanks for the reply. I am not Wolfgang, nor do I have anything to do with a posting from last week. Like I mentioned in my original communication to you, I had only found the fly on the same day (yesterday).
Are they rare to see? I’ve never seen one before.
Thanks for your time.

We are not certain how common Giant Yellow Robber Flies are in Australia.  Predators are generally not as common as prey.  By the way, the photography is just fine.

Giant Yellow Robber Fly

Giant Yellow Robber Fly

 

What's That Bug? does not endorse extermination