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

Subject: I’ve never seen this bug before….
Location: Delaware
July 20, 2014 5:29 pm
I’d really like to know what this bug is, why I’ve been seeing them so often lately, and why I have not seen them before (if that’s possible to answer).
I live in Delaware (the state in the US) and this summer I’ve been seeing these everywhere I go.
Signature: ….I don’t really have a preference?

Hanging Thief

Hanging Thief

We just posted a lengthy description of a Hanging Thief.  As to why you have seen them recently, we can only respond that insect populations fluctuate due to weather conditions, food supplies and other factors.  Then again, perhaps you have just gotten more observant.

What's That Bug? does not endorse extermination

Subject: what is this?
Location: North carolina (central)
July 20, 2014 10:23 am
Please tell me name of this bug never have seen anything like it–was on my back porch
Signature: c santana

Hanging Thief

Hanging Thief

Dear c santana,
This impressive, predatory Robber Fly in the genus
Diogmites is commonly called a Hanging Thief because they frequently hang by one or two legs while feeding.

What's That Bug? does not endorse extermination

Subject: Ovipositing Robber Fly
Location: Andover (Sussex Cty) NJ
July 20, 2014 5:51 am
I just thought I’d send this photo along to you because it was something I’d not seen before. I was walking on a lakeside trail looking for dragonflies when I saw this large robber fly ovisositing. She was so large that initially I thought she was a small dragon. I was able to crouch down and watch her for several minutes.
Signature: Deborah Bifulco

Female Robber Fly deposits eggs

Female Robber Fly deposits eggs

Hi Deborah,
Thank you for supplying us with this marvelous documentation of a Robber Fly in the act of ovipositing.  According to BugGuide:  “Adults lay eggs in the soil or in plants. A few, such as
Mallophora and Megaphorus form an egg mass on a plant stem. Larvae often predatory, consuming eggs and larvae of other insects in decaying matter. Typically overwinter as pupa, emerge in spring. Life cycle is 1-3 years.”

What's That Bug? does not endorse extermination

Subject: Two days in a row I came across these in the morning. Sacken’s Bee Hunterr
Location: Hemet Ca.
July 18, 2014 12:53 pm
I see that these kill our honey bees, I have found tow on the truck on two different days. I left them alone becasue I was not sure what they were. Now that I know, I want to kill them to protect our honey bees. your thoughts?
Signature: Lynn in So Cal

Bee Killer

Bee Killer

Hi Lynn,
Your mistaking this Bee Killer,
Mallophora fautrix, for Sacken’s Bee Hunter is understandable, but taking a closer look at the images posted to BugGuide and comparing them to images of Bee Killers in our archive will reveal some differences.  Sacken’s Bee Hunter has a yellow thorax and black abdomen with yellow tip, while your individual has a black thorax and yellow abdomen.  The antennae are also more thin and hairlike, and according to BugGuide, individuals in the genus Mallophora have :  “antennae with a very thin terminal final segment, whereas Laphria has thick antennae.”  We would urge you not to kill the Robber Flies as their predation is not the greatest problem faced by Honey Bees, and while the Robber Flies will prey on Honey Bees, they also feed on a variety of other winged insects.  Images in our archives show them preying on wasps.

Thank you so much for this information!. I have not nor will I kill these bee killers. I know everything has a place in the food chain and now that I know they do not just prey on our honey bees I will leave them alone, I found another this morning, I find it strange  to find one in the last 3 days. I need to read up on them to see if they have hives or nest?
Thanks again!!!
Lynn

Robber Flies are solitary hunters that do not have hives nor nests.

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