Currently viewing the category: "Cactus Flies"
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Subject:  unknown
Geographic location of the bug:  Phoenix, Arizona
Date: 01/28/2018
Time: 09:07 AM EDT
Your letter to the bugman:  maybe 6 or 7 mm long
How you want your letter signed:  Daniel Gronseth

Cactus Fly

Dear Daniel,
This unusual critter is a Cactus Fly in the family Neriidae, probably the Longhorn Cactus Fly,
Odontoloxozus longicornis, which is pictured on BugGuide.  According to BugGuide the habitat is:  “Deserts; larvae in decomposing cacti.”  Thanks to your submission, we have created a Cactus Fly category, moved previously uncategorized postings into the new category, and moved previous postings originally categorized as Stilt Legged Flies into the correct family category.

What's That Bug? does not endorse extermination

Subject: What bugs are these?
Location: Cairns, QLD, Australia
December 3, 2016 7:11 am
Found these in my yard.
Signature: CE

Stilt Legged Fly

Stilt Legged Fly

Dear CE,
Like another of your submitted images, we believe this is a Stilt Legged Fly in the family Micropezidae, but unlike the previous image, we have not been successful in finding any matching images from Australia online.  We are postdating this submission to go live to our site when we are out of the office for the holidays at the end of the month.

Correction Courtesy of Karl:  Banana Stalk Fly
Hi Daniel and CE:
This is actually a Banana Stalk Fly (Family Neriidae); we usually call them Cactus Flies in North America. Depending on which source you read, there are either two or three species in Australia. Of these, I believe Telostylinus lineolatus is the closest match. Regards, Karl

Thanks so much Karl.  Interestingly, we have a mating pair of Banana Stalk Flies from Hawaii in our archives, and that posting is also listed as Stilt Legged Flies.  We will create a Cactus Fly subcategory for both postings.

What's That Bug? does not endorse extermination

Subject: Small Insect, Red Eyes
Location: Singapore
February 2, 2013 10:37 pm
Hi there, I found this very minute bug roaming around the rotting stump of a fallen tree. This one is quite lighter in color than the other bugs similar to it. It has those pair of big red eyes. I’m not sure what this is really as it does not seem to be a fly (or could be)? Anyway, hope you guys could identify this one as closely as possible. Oh, sometimes it would wave its two front legs in a movement as if cleaning some sticky debris off its limbs.
Thanks!
Signature: Giovanni

Cactus Fly

Hi Giovanni,
This is in fact a Fly in the family Neriidae which are commonly called Cactus Flies because the “larvae are decomposers of cactus” according to BugGuide.  It might be a Banana Stalk Fly,
Telostylinus lineolatus.  The family is sometimes referred to as Stilt Legged Flies as well, though that name can also refer to the members of the closely related family Micropezidae.  According to the Evolutionary Biology Lab:  “Neriidae is a relatively small family of true flies (Diptera) with long, stilt-like legs. Most species are found in the tropics. Neriids have very interesting behaviours, and many species are strikingly sexually dimorphic, with males having much longer legs, heads and/or antennae than females. Like piophilid flies, neriid larvae have the ability to leap during the stage just before pupation when they migrate from the larval feeding substrate to the pupation site. Very little research has been done on this interesting group of flies.”

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Special Mosquitos?
Location: Palolo Valley, Honolulu, HI
December 16, 2010 5:39 pm
Found these two getting busy on the shoe rack this morning… I hope they don’t recognize and remember faces for an attack later on when they’re done… Are these special mosquitoes or something? They sure don’t look like a regular Mosquito!
Signature: TH

Mating Banana Stalk Flies

Dear TH,
Wow, what an awesome photo you have sent to us.  We have no idea where to begin researching the identity of these unusual looking mating Flies, but we can assure you that they are not mosquitoes.  Like so many other creatures in Hawaii, we suspect these might be an introduced species, possibly from Asia.

Immediate Update
We quickly found a match for your mating Flies.  They are identified on BugGuide as Banana Stalk Flies, Telostylinus lineolatus, in the family Neriidae, the Stilt Legged FliesThe Cook Islands Biodiversity website has a page devoted to the Banana Stalk Fly, and they list the other common names Banana Fly, Push-me-Pull-me Fly and Push-pull Fly.  The range is listed as “Sri Lanka – Indonesia / Australia – Marquesas, Hawai‘i” and it is considered a pest species, but the site does not indicate why.  The Rainforest Revelations website has this information:  “With enormous eyes, this tiny, tropical, stilt-legged fly maintains a confident distance from human approach, by swiftly running around the blind-side of whatever surface it is on.  … Telostylinus lineolatus inhabits tropical north Queensland, where it aggregates on flowers and rotting fruit.  They are members of Neriidae, which is a relatively small family of true flies (Diptera) with long, stilt-like legs.”  The Evolutionary Biology Lab Research website has this information on the family:  “Neriidae is a relatively small family of true flies (Diptera) with long, stilt-like legs. Most species are found in the tropics. Neriids have very interesting behaviours, and many species are strikingly sexually dimorphic, with males having much longer legs, heads and/or antennae than females. Like piophilid flies, neriid larvae have the ability to leap during the stage just before pupation when they migrate from the larval feeding substrate to the pupation site. Very little research has been done on this interesting group of flies.

Correction January 2, 2017
Though we correctly identified the species, we now know that Banana Stalk Flies are in the Cactus Fly family Neriidae.

What's That Bug? does not endorse extermination

Weird fly from the Philippines (2)
December 27, 2009
Dear Bugman,
What’s this bug?
I saw this guy on the outer wall of our house. At first I though it was some kind of assassin bug, but then I realized it must be some strange kind of fly! I had never seen its kind before.
Could you let me know what it is?… Thanks!
Kulisap
Luzon, Philippines

Unknown Fly

Cactus Fly

Dear Kulisap,
We do not recognize this fly and we will post its image in the hopes that one of our readers may be able to provide a response.  If you post a comment to the posting, you will be informed automatically if someone writes to us in the distant future.  Your photos are quite good, and we hope we get a proper identification, at least to the family level.

Unknown Fly

Cactus Fly

Update:  December 30, 2009
After some searching I think I was able to identify this critter… it seems to be a type of cactus fly (Neriidae).
I also found this link:
http://www.bonduriansky.net/neriidae.htm
Thanks again for the reply!
Kulisap

What's That Bug? does not endorse extermination

Summer visitor to chapparal country in Southern California
First of all, I love your website. The variety of life on this planet is more fantastic than any other I’ve visited (at least in recent memory)! My wife and I have long wondered about a winged insect that shows up each year as the weather warms. It seems to like red wine; whenever we go in the backyard with a glass they seem to end up treating our glasses as their personal spa. Since it’s quite dark and looks a bit like the villains in the ‘Babylon 5’ TV series, we call them ‘Shadow Bugs’. They don’t seem harmful; at least they haven’t bitten us yet! We live on the edge of a rocky hill covered in chapparal (cactus, sage, and other desert shrubs). My wife grew up very near here, but in a more urban area and never saw one until we moved to our current house. I would estimate that this critter is between 3/4 of an inch and 1 inch long. In hopes that you can tell us what they are I’m enclosing two pictures. Thanks!
jeff fielding
orange, california

Hi Jeff,
After doing some research, we believe this to be a Marsh Fly in the genus Sepedon. We located some images on BugGuide that look very similar. Perhaps some expert will write in with an exact species.

Correction: Cactus Fly
Provided by Eric Eaton (09/23/2007)
Daniel:
The “marsh fly” is actually a “cactus fly” in the family Neriidae. Fantastic image! We could use it over at Bugguide, as this family is under-represented. Larvae of these insects develop in rotting cacti.
Eric

Correction
(09/23/2007) Maybe a Marsh Fly – not a marsh fly
Hi guys,
I enjoy the site. Your “Maybe a Marsh Fly” from 9/21/2007 is actually a Cactus Fly – Odontoloxozus longicornis. The larvae hang out in decaying cactus. Interesting that the adults like red wine, I’ll forced to experiment with that. Darn. Cheers,
Michael W.

What's That Bug? does not endorse extermination