Currently viewing the category: "Robber Flies"
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Hi, can you help me identify this fly?
Hi, My name is Cary and I found a fly that I cannot identify. I live in the Orange County area of Calfornia. As I began walking to my car to leave the beach, I noticed a fly on the wall. It was about 1.5" long and at first glace, it looked like a dragonfly because of the large hump on the back of the head and the long abdomen but the wings were not perpendicular to the body; they were laid back like a regular fly. To my surprise, I put my finger in front of it and it held on so i walked to my car with this fly on my finger and managed to drive all the way back home so that i would be able to take pictures of it. I hope that these pictures are good enough for identification. If you would like, I can also send a short video if it as well.
Thanks,
Cary

Hi Cary,
You have sent in a photo of a Robber Fly from the Family Asilidae. They are swift flying predators that pounce on resting insects from above. We would have loved to see the photo of the Robber Fly on your finger. They have keen eyesight and are very difficult to approach since they are quick to take flight.

Thanks for your help and quick reply! I was reading around about the robber fly and I learned that it has a proboscis which could inject a toxin into its prey, which then dissolves the meal internally, which then gets sucked up by the big fly. Sounds as if it were a flying spider! The experience really makes me think about how many oppertunities it had to sting me but didn’t. Very cool!
Thanks again,
Cary

What's That Bug? does not endorse extermination

Any idea what this is, I live on Vancouver Island, Canada, and have seen a number of these insects attacking and killing wasps and bees. Any info would be appreciated.
Thanks
Stuart Clarke

Hi Stuart,
You have a totally awesome photograph of a Robber Fly, Family Asilidae. There is one genus, Laphria, known as Bee Hunters. Your fly belongs to that genus. Adults feed on Honey Bees, though your photo shows a Yellow Jacket being devoured. A species in California and Oregon is Sacken’s Bee Hunter, Laphria sackeni. Also, the larvae of robber flies are pretty much now assumed to be parasitic on beetle grubs. According to our Audubon Field Guide: “Sacken’s Bee Hunter flies rapidly and suddenly descends on an unsuspecting bee. It seizes its victim on the thorax so the bee cannot use its stinger.” You might want to submit your photo to the new field guide we advertise at the top of our homepage.

What's That Bug? does not endorse extermination

I need help identifying something strange (like you don’t hear that all the time). I was out on my porch the other day when I heard a buzzing sound from what I assumed was some sort of beetle or something. There are a lot of bugs around our wooded lot in western Virginia, so I didn’t think anything of it until it landed on the chair next to me. It was big (about 2 1/2" long and fairly "beefy"), blackish, and resembled a locust except for the soft yellow and black ringed body that tapered to a point at the end. I couldn’t see the wings while it was sitting there, but obviously it had some. I was immediately reminded of something from a sci-fi movie or a prehistoric critter on the Discovery Channel. I’ve looked everywhere and can’t find any descriptions or pictures resembling it. However, I’ll certainly be sure to take my camera with me whenever I take a cigarette break from now on.
-Michaele
(08/16/2004)
This is quite coincidental, in fact, because not two seconds before I checked my e-mail, it had returned out on my front porch and I was able to snap a picture. It’s not very good because I couldn’t get too close before it flew away, but here it is.
Michaele Davis

Hi again Michaele,
I’m glad you got the photo. You have a species of Robber Fly, Family Asilidae. These are predatory flies that it locates with those big eyes and often captures on wing. They are beneficial, though will bite people if mishandled. Based on your original description and your blurry photo, it seems like you have a Bee Killer also known as a Giant Robber Fly, Promachus fitchii. They are found in meadows and near honey bee hives from Massachusetts to Florida and west to Texas and North to Nebraska. According to our Audubon Insect Guide: “The Bee Killer often rests on leaves and branches with a clear view of flowers visited by Honey Bees. It seizes its victim from above, pierces its body and sucks out juices, then drops the emptied prey. A dozen or more bidies may pile up on the ground below a favorite perch.” Size can be deceptive. This species reaches 1 1/8 inches in length.

What's That Bug? does not endorse extermination

BugMan,
I am hoping you can help me identify this bug. I have had several of them flying in my house and one has stung me (At least I think it was one like this, got me on the back of the neck, and since I did not see it and this is the only flying bug I have seen in my house I have given it the blame.) I know this is a picture of a dead bug and I really strive not to kill bugs but it was flying around in my daughters room and she would not calm down (4 years old would not stop crying) until it was dead and she could see it. So needless to say I was forced to kill it so I could sleep (Does this make me a bad person?). I live in Essex, MD, it was about an inch and a half long, 6 legs, long slender tail, big bug eyes, and 2 small antenna on its head (1mm maybe 2mm), one set of wings that were tan from top to bottom with only supports throughout no other coloring, and a small roundish buldge on the top of its back above the wings with stripes of brown and black. I am attaching 3 pictures to see if you can help identify it. Thanks for all your help.
Sincerely,
Matthew Rebbert

Hi Matthew,
Your insect is a Robber Fly, Family Asilidae. The adults are predatory, and are important in the control of many insect pests including Grasshoppers. The Robber Fly will attack insects much larger than itself. They are capable of inflicting a painful bite if carelessly handled, but they do not normally bite people. Robber Flies often find their way into homes. We would recommend trapping it in a glass when it alights on the window, and then releasing it. Show your daughter that the fly was taken outside so it could kill other bugs. Eric Eaton adds “Your specimen of Robber fly (reddish-yellow with black stripes) are Diogmites sp., the Hanging Thieves,” named for the way they suspend themselves from one pair of legs while feeding on a prey item.”

What's That Bug? does not endorse extermination