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

Subject: ZZtop Fly that just sat there
Location: Dallas area Texas
July 16, 2014 8:34 am
Found this rather large fly on my car. He sat there for over a day in the hot sun. I set the P&S on macro and captured these shots. The white tip on his tail, and the lines aon his back should be distinctive. The hairy face reminded me of ZZ Top – a Billy Gibbons fly?
Any idea what this one is called?
Signature: Richard Todd

Robber Fly

False Bee Killer

Hi Richard,
This is a predatory Robber Fly in the family Asilidae.  Thanks to Bugs In The News, we believe we have correctly identified your individual as a member of the genus
Promachus, the Giant Robber Flies, possibly Promachus bastardiiBugGuide tends to substantiate that identification.  BugGuide indicates the common name for this species is the False Bee Killer.  Bugs In The News also provides this information:  “Robber flies are equipped with a short, but strong proboscis which is used like a sword to pierce the integuments of their prey. The proboscis is further equipped with an orifice, distally, through which salivary secretions are injected into the prey. These secretions contain neurotoxic enzymes that paralyze and incapacitate, and proteolytic enzymes that digest animal tissue. Once the robber fly attacks and subdues its prey (which often includes insects of its own family, and even its own species; robber flies are notorious as true cannibals), it remains attached via its proboscis until the prey’s internal tissues have been digested to a liquefied state, whereupon it sucks the ‘nutritious’ (!) liquid up through the same orifice that delivered its salivary secretions, to consummate its grand, though — from a human perspective — disgusting, feast.”

False Bee Killer

False Bee Killer

What's That Bug? does not endorse extermination

Subject: what is this thing I killed at work
Location: St. Louis, MO
July 10, 2014 1:06 am
this creature was flying around my head today at work. it must have gotten inside when a customer walked in the door. anyway, it flew like a wasp or maybe even a mosquito and it was about an inch or inch and a half in length. as soon as it landed where I could kill it, I didn’t hesitate. so I’m just curious as to what this thing is!
Signature: Nikki

Swatted Robber Fly

Swatted Robber Fly

Dear Nikki,
Even in its swatted state, this Robber Fly is a magnificent creature.  Robber Flies are beneficial predators and they will not attack humans, though they might bite if carelessly handled.  We believe your Robber Fly, a victim of Unnecessary Carnage, is a Hanging Thief.

What's That Bug? does not endorse extermination

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

Bee-Like Robber Fly

Bee-Like Robber Fly

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

Bee-Like Robber Fly

Bee-Like Robber Fly

 

What's That Bug? does not endorse extermination

Subject: Unknown Fly
Location: Great Salt Lake, Utah
July 5, 2014 3:22 pm
While on vacation, I stopped at the Great Salt Lake in Utah. On the shores of the lake, there was these flies that were about 1 1/2 inches in length and were large enough to cast a shadow as they were flying. I am somewhat familiar with insects but I haven’t seen any like these before.
Signature: Brandon

Robber Fly

Robber Fly

Dear Brandon,
This is a Robber Fly in the family Asilidae, and we will attempt a more specific identification later today.

What's That Bug? does not endorse extermination

Subject: Ichneumon Wasp?
Location: West Milford, New Jersey
July 3, 2014 6:48 am
I have looked at lots of pictures, but I cant ID this insect. I have seen them in my garden a few times, I feel like it may be a Ichneumon Wasp, but I have been unable to match anything with the dark band/stripe down the middle of the thorax.
Signature: Geoffrey Syme

Mating Robber Flies

Mating Robber Flies

Hi Geoffrey,
These are mating Robber Flies in the family Asilidae.  We will attempt to identify the species.  Based on images posted to BugGuide, this appears to be
Asilus sericeus.

What's That Bug? does not endorse extermination

Subject: Dragonfly relative / nymph?
Location: Austin, Texas
June 19, 2014 2:21 pm
I spotted this flying insect on a purple coneflower near an area with man-made ponds and lots of dragonflies, turtles and fish. When the insect flew away, there was a buzzing sound.
Signature: Susan

Red Footed Cannibalfly

Red Footed Cannibalfly

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!

Hi. I actually figured out (after much research) that the photo I submitted was of a robber fly (aka assassin fly), Asilidae…and further narrowed it down to a variety of Diogmites. I can’t seem to take it any further, as I haven’t seen any of these with abdomens as long as the one in my photo.

Hi Susan,
We were away from the office when you wrote, and we are trying to catch up on old mail, posting some of the more interesting images we received in our absence, including yours.  Your identification is only partially correct.  While this is a Robber Fly in the family Asilidae, it is not a Hanging Thief in the genus
Diogmites.  It is a Red Footed Cannibalfly, Promachus rufipes, and you can compare your excellent image to the images posted to BugGuide.

What's That Bug? does not endorse extermination