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

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.

Robber Fly eats Cicada

Robber Fly eats Cicada

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

What's That Bug? does not endorse extermination

Subject: Looks to be a Red-footed Cannibalfly
Location: Franklin, TN (Nashville area)
August 11, 2014 1:32 pm
We’re looking for a confirmation on this being a robber fly. Your site was soo helpful in both researching what we saw out our front door and learning more about the bug in question.
This guy was about 3 cm in length and “snacking” on a wasp.
Our 3 and 5 yr old were fighting for the best position to watch this guy through a window. Question – how bad would a bite from this guy be to a small kid? And, is it okay to hang out around them as they protect our air space?
Signature: Jeff

Red Footed Cannibalfly eats Paper Wasp

Red Footed Cannibalfly eats Paper Wasp

Hi Jeff,
We agree that this is a Red Footed Cannibalfly, and it appears to be eating a Paper Wasp in the genus
Polistes (See BugGuide).  We believe a bite from a Red Footed Cannibalfly would be painful, but otherwise present no lasting effects, however we should qualify that that we believe the chances of being bitten are at about 0% unless a person decided to try to catch a Red Footed Cannibalfly by hand.  They are not aggressive towards humans, and if provoked, they would most likely just fly off.  Handling them is a totally different matter.

What's That Bug? does not endorse extermination

Subject: Very large bee insect
Location: Cumming, ga
August 9, 2014 4:00 pm
Hello,
The attached picture looks like a very large bee, but it has long legs, flies, has a furry ruff around it’s neck and was on my green car side view mirror the other day. I’ve never seen anything like it.
Signature: Marisa

Red Footed Cannibalflies

Red Footed Cannibalflies

Hi Marisa,
This is the fourth image we are posting today of a Red Footed Cannibalfly, a large predatory Robber Fly, including one image of a mating pair of Red Footed Cannibalflies.
  Add to that two images of Hanging Thieves, another type of large Robber Fly, and that makes a total of six Robber Flies posted today.  We are declaring today the Day of the Robber Flies.

What's That Bug? does not endorse extermination

Subject: Big identity please
Location: Eastern US in Columbia md
August 9, 2014 11:15 am
Hello. Live in Columbia MD. Saw these two on my wood deck. When I took their picture they buzzed off. It’s summer here.
Signature: Thank you, Lisa

Mating Red Footed Cannibalflies

Mating Red Footed Cannibalflies

Hi Lisa,
This is peak season for large Robber Flies like these mating Red Footed Cannibalflies.  This is the fifth posting today to our site of Robber Flies and the third for this particular species, the Red Footed Cannibalfly,
Promachus rufipes.

What's That Bug? does not endorse extermination

Subject: Dragonfly but not?
Location: Nashville
August 8, 2014 4:56 pm
I saw this strange bug in the backyard. It has a body shape like a dragon fly, but there only seem to be two small wings and the eyes and mouthparts don’t look typical for a Dragonfly. What would you say it is?
Signature: Chris

Red Footed Cannibalfly

Red Footed Cannibalfly

Hi Chris,
We have been deluged with Robber Fly requests this morning, and your individual is a Red Footed Cannibalfly.

What's That Bug? does not endorse extermination

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

Hanging Thief

Hanging Thief

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

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

What's That Bug? does not endorse extermination