Skip to main content

Red-footed Cannibal Fly

You won't want to mess with this one. Some of the robber flies are truly beastly-looking insects, and the Red-footed Cannibal Fly, Promachus rufipes, is one of them. Robber flies are highly predatory, and as Kenn Kaufman aptly notes in his book Field Guide to Insects of North America, they are "...to other insects what falcons are to other birds".


As with so many insects, too little is known of many species' life histories and distribution. I took these photographs in and around prairies in Adams County over the past few weeks, and have seen this species there on several visits. It's the only place that I've noticed them, but perhaps they are more widespread. Whatever the case, the Red-footed Cannibal Fly is an amazing insect. Big, the size of a huge wasp but much more bulked up, they hunt patiently much like flycatchers or some dragonflies. Sitting tight on a prominent perch, the cannibal fly waits for suitable victims to fly by. With eyes like this, they don't miss much. Rather tame, they will allow close approach if you are careful in your movements. Then, you can watch the insect tilt its head about as it watches potential prey wing by, waiting for a good victim. When it sees something it likes, the cannibal fly dashes out after it like an F-16 scrambling after enemy aircraft and seizes it in those long legs, wrapping the victim tight and injecting it with its proboscis-like mouthpart.

There is little hope of escape once the prey has been ensnared by those powerful legs reinforced with stiff raptorial spines. Soon, the paralyzing chemicals that the fly injects into the victim's tissue goes to work, and paralyzes it. Acid-like, the toxins break down and liquify the innards of its meal, and eventually the cannibal fly sucks out the contents just as we would tap the sweet liquid of a chocolate milkshake through a drinking straw.

The Red-footed Cannibal Flies are watching, always watching. I'll tell you this, if I were some small and relatively defenseless bug, I would not want to bumble into the sights of this thing. Species in the robber fly family are some of the world's fiercest insects, and larger species have even been known to take down hummingbirds, allegedly.

Comments

Anonymous said…
I saw one in northwest Florida yesterday and have never seen one before. It was on a stick, prey I'm it's arms. It was a mean looking thing.
Anonymous said…
I live in southern ontarion and have been seeing them in my yard alot latly. I too have never seen them befor till now. And being someone who is petrified of bugs this one freaked me out pritty bad to say te least.
Anonymous said…
8/3 saw one in hamilton ohio, it flew into my car window. had to pull over and wait until he flew out. luckily i have a convertable. what a creepy bug.
Anonymous said…
I live in Kingwood, TX about 30 miles north of Houston and just came across one. Got some cool pics of it.
Spotted Crow said…
Just saw one today in NE CT. I was hanging a tree stand. Startled the bazeebas out of me.
ABaker1127 said…
I saw one on 8/23/13 on my front window screen with a big yellowjacket in its mouth. Kansas City, MO
Anonymous said…
I'm in Atlanta, GA and one landed uncomfortably close to me while I was sitting on my deck. Took some pics with my phone and showed them to my husband. We'd never seen a bug like that. Google helped us ID it. Scary thing!
Anonymous said…
I saw one in Indiana! It freaked me out cause it was sucking the guts out of a horsefly
Katie Devore said…
Saw one in a suburb near Detroit, MI. Horrible bug and aggressive! Even towards me, as I swatted it away it lunged in response as if to challenge me. Have they been known to bite people?
Anonymous said…
Just found one stuck to an outside door in rural Copiah County Mississippi. Have never seen anything like it but apparently they are wide spread. Glad to know they go after wasps but sorry about the poor hummingbirds - we have both! These are some crazy looking bugs for sure!
Tracy Shuck said…
Saw over today in Quakertown PA. Never saw one before scary!
junior robinson said…
Just had one on my side mirror. Manassas, va
Anonymous said…
had one land on me three days ago. swatted it off then took pictures of it. Chattanooga, TN.

Popular posts from this blog

The Pinching Beetle, a rather brutish looking bug

The world is awash in beetles, and they come in all shapes and sizes. Few of them can match the intimidation factor of a Pinching Beetle, Lucanus capreolus, though. Those formidable looking mandibles look like they could slice off a finger.

Today was one of those coolly diverse days. I started off down in Fayette County, visiting the farm of a friend. He has restored about 25 acres of wetlands, and the response by the animal community has been nothing short of phenomenal. Blizzards of dragonflies of many species, amphibians galore, and nesting Blue-winged Teal, Pied-billed Grebe, and Sora. Among MANY other things. And all in a short two years. Add water and they will come.

Then, working my way home, I ducked into a Madison County cemetery that has a thriving population of Thirteen-lined Ground Squirrels, and shot images of our native prairie dog. Then, I stopped at a spot along Little Darby Creek, waded on in, and procured some pretty nice shots of various stream bluets and dancers. …

Calliope Hummingbird in central Ohio!

A hatch-year male Calliope Hummingbird strikes a pose. Small but tough, the hummingbird was feeding actively yesterday in 39 F temperatures. It frequents feeders and gardens at a home in Delaware County, Ohio, about a half-hour north of Columbus.

Fortunately, the wayward hummer appeared at the home of Tania and Corey Perry. Tania is a birder, and knew right away that the hummingbird was something special. For a while, the identification was up in the air, which isn't surprising. The Calliope Hummingbird used to be placed in its own genus, Stellula, but has recently been submerged into the genus Selasphorus, which includes Allen's, Broad-tailed, and Rufous hummingbirds. The latter two, especially, are quite similar to the Calliope in subadult plumage. Rufous is the default "vagrant" hummingbird here, with dozens of records and birds turning up annually. There is but one Ohio record of Allen's Hummingbird, from late fall/early winter 2009. Ditto the Calliope Hummi…

Ballooning spiders

Fear not, ye arachnophobes. The subject of this entry is indeed about spiders, but the star of the show is about as cute as a spider can get. And you'll want to know what we're about to learn...

On my recent West Virginia foray, we were strolling down a seldom-used lane, when a bright yellow object caught our eye. It was a goldenrod crab spider, Misumena vatia, on top of a post! Not only that, she - it is a girl - was acting extraordinarily goofy. The spider would stilt up as high as she could go on her legs, weave back and forth, jig side to side, and otherwise engage in what appeared to be spider break-dancing.

Click the pic for expansion, and you can see two columns of silk issuing from her spinnerets. This is an important point, as we set about determining what this non-web-making spider is doing.


So fixated was our spider on her task that she even rejected what would seem to me to be a perfectly scrumptious meal. This little caterpillar climbed rapidly up the post and dire…