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

is This an Ant?
June 4, 2010
I found this ant outside on my wall then he flew to a chair, I’m located in Central Florida, Polk County USA..
I’m not sure if its an ant or other type fo bug any help would be appreciated… thanks 🙂
Thanks Dee
Florida Usa

Stilt Legged Fly

Hi Dee,
This is a Stilt Legged Fly in the family Micropezidae.  According to BugGuide, they are “Odd little flies, known for their displaying (?) behavior of walking around and lifting their prominently marked front legs. Abdomen attached to thorax by “wasp-waist”. Likely ant or wasp mimics. The posture of the forelegs may imitate ant and/or wasp antennae and provide them with some protection from predators (speculation–Cotinis).
”  We will leave species or genus identification for an expert in the field.

What's That Bug? does not endorse extermination

Flying At or Wasp?
January 19, 2010
Hi,
I live in St. Thomas in the US Virgin Islands. The other night I woke up and found several large bites on my chest. I was thinking bedbugs but my girlfriend has no bites. Its happened to me several times. The difference is I sleep on top of the covers and she usually is bundled up under. So Im thinking that might rule out bedbugs. Then this morning we found this bug in the bedroom. What is it and can it be the culprit thats biting me? The bites first feel like acid on my skin and stings real bad then they becomes very itchy. Thanks for your help.
Eric Stone
Crown Mountain, St. Thomas, USVI

Stilt Legged Fly, a victim of mistaken identity

Hi Eric,
It is not our mission to demonize our readership, but rather to educate, which is why we are tagging your letter as Unnecessary Carnage.  This is a Harmless Stilt Legged Fly in the family Micropezidae.  It did not bite you, so that culprit is still awaiting identification.  Stilt Legged Flies are noteworthy for the manner in which they wave about their prominently marked front legs as though they were trying to signal something.

Thanks Daniel,
I appreciate the info.  I will let my friends know on Facebook what the fly is and tell them to be kind to it. I will also add a link to my website to yours and let people know that you guys have the answers. Mahalo!
Thanks, Eric Stone

What's That Bug? does not endorse extermination

weird fly from the philippines (1)
December 27, 2009
Dear Bugman,
What is this bug?
It is very common in gardens. Its distinctive characteristic is that it constantly waves its two front legs around (white-tipped) as if engaging in semaphore.
It must be some kind of fly, but which one?
Thanks for the attention!
Kulisap
Luzon, Philippines

Stilt Legged Fly

Stilt Legged Fly

Dear Kulisap,
We tried doing a web search of “fly waves front legs” and came up with a cirrusimage page on the Stilt Legged Fly family Micropezidae that states:  “I would have called this the ‘semaphore’ fly, in that it constantly waves its front legs around as if signaling someone or something. Popular science has it they are mimicking ant or wasp antennae, but I’m not sold on that theory. Wasp antennae are jointed and “droop”  and certainly don’t wave about like this fly does.
”  According to BugGuide:  “Odd little flies, known for their displaying (?) behavior of walking around and lifting their prominently marked front legs. Abdomen attached to thorax by “wasp-waist”. Likely ant or wasp mimics. The posture of the forelegs may imitate ant and/or wasp antennae and provide them with some protection from predators.”  It is interesting that both you and the person who wrote the cirrusimage posting likened the behavior of the fly to semaphore.

What's That Bug? does not endorse extermination

Flying Ant or Fly
September 23, 2009
This little guy hangs around my computer and other places on my desk “washing his hands and feet”, “scratching his head” and staring at me all day long. He is not timid of me at all. I can put my finger in front of him and he will walk up onto it. He seems to be content sitting still for long periods of time, then abruptly he will scatter. He is very quick when he wants to be. He didn’t seem to like me taking his picture either. I have also seen him riding inside my truck on the rearview mirror when I go on road trips. What is he and what does he want?
Weirded Out In Florida
Panama City Beach, FL.. Northwest Florida Panhandle

Long Legged Fly

Stilt Legged Fly

Dear Weirded Out,
WE believe this is a species of Long Legged Fly in the family Dolichopodidae, but sadly, we have been unable to find a species match on BugGuide.  Long Legged Flies are predatory species that prey on small insects, so they are beneficial and will not harm you.

Eric Eaton Responds
Daniel:
No trouble, but I’m answering from a friend’s computer….The fly is a “stilt-legged fly,” family Micropezidae.  Easy to get them confused with longlegged flies, family Dolichopodidae.
Eric

Update
BugGuide indicates this of Stilt Legged Flies:  “Odd little flies, known for their displaying (?) behavior of walking around and lifting their prominently marked front legs. Abdomen attached to thorax by ‘wasp-waist’. Likely ant or wasp mimics. The posture of the forelegs may imitate ant and/or wasp antennae and provide them with some protection from predators
.”  Also, we believe it looks like it might be Compsobata univitta.

Update:  May 18, 2014
Thanks to a new comment, we know that this is
Grallipeza nebulosa, a Stilt Legged Fly that is pictured on BugGuide.

What's That Bug? does not endorse extermination