Mydas flies have a golden band across their bodies and are named after the legend of king Midas. But where are Mydas flies found around the world? What is their habitat like? Let’s find out.
Belonging to the family of flies under Mydidae, Mydas flies are a harmless bunch, despite their rather large and intimidating wasp-like appearance.
Their family name comes from the name of King Midas – a mythological king with the ability to turn anything into gold based on touch!
Mydas flies sport an orange-golden colored band – which could possibly have led them to have this name.
These flies feed on nectar and pollen from flowers and thrive in warmer climates like the tropics and sub-tropics.
They are found in both dry and warm areas, such as the deserts in the southwest of North America, as well as the warm and humid grasslands.
Rotting tree carcasses in such areas are especially good hosts for the larvae to feed on.
What Are Mydas Flies?
The Mydas Fly is a species of large fly with an iridescent black colored body, with bands of red, orange, or yellow and legs dotted with golden-orange specs.
They have a long, barrel-shaped abdomen which is further segmented into three parts. Their rear legs are longer and more muscular than those of other flies.
Their feet are cushioned with spiny bristles running along.
Mydas flies may range in size from ¼ to 1¼ inches, with the largest being 2 inches! They look quite similar to Robber flies, belonging to the family of Asilidae.
However, unlike robber flies, this fly species sports singular, clubbed antennae.
Where Are They Found?
Thriving in most tropical and sub-tropical areas, this fly species hosts almost 400 species of flies worldwide – a relatively small number as compared to other families.
North America itself is home to around 80 of these species, with the Mydas clavatus being the most commonplace.
Within these areas, adult flies can be found anywhere, from open grasslands to forests, feeding on plants or burrowing in the sand.
Those in the larval stage can be found in dead or decaying trees. In the pupae stage, they are found burrowed within the earth.
How Long Do Mydas Flies Live?
Since they have not been extensively studied, there is not much credible information regarding their life span.
Though like most flies, it is believed that adult flies have a very short lifespan.
In general, a female Mydas fly will lay eggs after burrowing in the soil in soft, rotting trees. The male of some species may scout suitable sites for laying eggs.
The eggs hatch into larvae which feed and grow over several instar stages.
The larval stage may last for a year, after which the larvae burrow into the group to form pupae.
The adult fly, using its spiny legs, will emerge from the soil. After a small rest, it flies off as an adult.
The time of development from larvae to adult flies may also vary based on the weather. For example, adult flies wait for the hottest hour of the day before emerging from the soil.
Defense Mechanisms of Mydas Flies
Harmless insects like the Mydas fly often employ defense mechanisms such as Batesian mimicry.
This is a type of defense where harmless animals may evolve over time to look similar to potential predators of their own predator or venomous species.
The Mydas fly also takes on this approach by mimicking wasps. Their longer rear legs in flight and translucent wings make them look quite similar to spider wasps.
In fact, it also mimics a stinging motion upon landing – but cannot actually sting. That’s because the Mydas fly does not have a stinger or ovipositor to lay eggs.
The hoverfly is another example of a fly that mimics looking like a honeybee but is not a stinging species.
What Does It Feed On?
In the larval stage, the flies feed on beetle grubs, usually found in rotting trees. They might also feed on other larval animals, such as caterpillars or smaller flies.
As winged adults, these flies sustain themselves on pollen and nectar. Some common plants they visit are milkweed and Appalachian mountain mint.
Unlike the larvae, who are adept soil hunters, adult flies might even have atrophied mouthparts – making it impossible to feed.
Frequently Asked Questions
Where do Mydas flies live?
Mydas flies are a common species found throughout the world, mostly in grasslands and woodlands, as well as in arid deserts.
Apart from North America, they are also found in sandy Australian regions, especially along the east and west coasts.
Do Mydas flies bite or sting?
Mydas flies as adults are harmless and cannot bite or sting. However, they do mimic a stinging motion when in danger, similar to that of wasps. The motion remains a mimicry and not an actual sting!
Are Mydas flies beneficial
Mydas larvae feed on beetle grubs, which are known to eat and damage leaves and crops. Hence, they are considered to be beneficial in gardens and agricultural places. Moreover, adult flies, when searching for nectar, help in pollinating.
Are Mydas flies dangerous?
Despite growing to as much as 2 inches in size and resembling wasps to the untrained eye, Mydas flies are a harmless species.
One of the key differences that can help you spot a Mydas fly from a wasp is the pair of wings.
Belonging to Order Diptera, the adult flies have one pair of wings. Wasps, on the other hand, have two pairs.
Wrap Up
While relatively common across the world, the Mydas fly is rarely seen due to its short lifespan as an adult.
Moreover, their family size is quite small, and their sightings are infrequent as compared to the other fly families.
They certainly draw attention due to their large size. However, the next time you see one – remember that they are harmless and good for the environment!
We hope you enjoyed reading about this elusive and mesmerizing insect!
Reader Emails
Mydas flies are a fascinating watch, and many of our readers have been blessed with sightings of this gorgeous, yellow-banded fly.
These bugs are available almost all across America, and our readers have created a small library of photos for us to enjoy through their emails.
Please see these emails below.
Letter 1 – Mydas Fly
Subject: Wasp or fly????
Location: Cape Coral, FL
June 1, 2015 7:51 am
Found this on the porch yesterday. It’s at least an inch long and doesn’t appear to have a stinger. We live in SW Florida by the Caloosahatchee River. It was found in the middle of the afternoon. I’ve tried to ID it, but can’t find exactly what it is. But everything leads me to some sort of fly…but man does it look waspy. Please help, want to make sure it’s not dangerous. Thanks.
Signature: Jessica
Dear Jessica,
This harmless Mydas Fly in the family Mydidae is a magnificent insect, and many of the members of the family mimic wasps as a defense since the flies do not sting, but they benefit from resembling stinging insects. We believe we have correctly identified your Mydas Fly as Phyllomydas parvulus based on images posted to BugGuide. The Beautiful Wildlife Garden site has some great images and information.
Letter 2 – Mydas Fly
Subject: BODYOFAGRASSHOPPER
Location: Elizabethton, Tennessee
July 18, 2015 4:33 pm
We have spent 5 hours trying to figure out what the heck this is please help!!!!!!
Signature: Jeniffer Carver
Dear Jeniffer,
This very effective wasp mimic is actually a harmless Mydas Fly, Mydas tibialis, and you can verify our identification on BugGuide.
Letter 3 – Mydas Fly
Subject: What kind of bug is this?!
Location: Warsaw, IN. Northern Indiana close to the country.
July 19, 2016 12:52 pm
we found this on our grill when we were watering our plants & we are dumbfounded by what kind of bug this is.. thank you!
Signature: Britney England
Dear Britney,
We believe we have correctly identified your Mydas Fly in the family Mydidae as Mydas tibialis which is described on BugGuide as: “Black body, smoky wings, brown legs.” BugGuide describes the harmless members of this family as being: “Large flies, often wasp mimics. Have prominent, clubbed antennae and distinctive wing venation.” Though they mimic wasps, Mydas Flies neither sting nor bite and they pose no threat to humans.
Letter 4 – Mydas Fly
Subject: Birdbath victim?
Location: Memphis, TN
June 12, 2017 3:44 am
I’m a long-time reader and fan. I’m sorry the photos aren’t any better, but can you tell me what this lovely critter is? I saw it crawling around my birdbath before sunup this morning (June 12). When it got lighter and I went out to see if it was still there, the poor thing was *in* the birdbath. I fished it out, took photos, and then put the bug in a sort of hidden place on the ground so it can revive before a bird eats it (assuming it didn’t drown).
Thanks so much for your website. It’s a constant source of wonder to me.
Signature: Laurel
Subject: Birdbath victim part 2
Location: Memphis, TN
June 12, 2017 4:00 am
Is it mydas clavatus?
I’m happy to report that I just went out to check on this little critter, and it is alive! It has dried out enough to pull its wings in. So I don’t see the orange spot now, but I do see pretty iridescent wings covering it.
Signature: Laurel
Dear Laurel,
We apologize for the delay in responding. We were away from the office for nearly two weeks and we are attempting to respond to as much unanswered mail as possible (an impossible task) and posting the best letters. This Mydas Fly is indeed Mydas clavatus, and your intervention in its life warrants tagging this submission with the Bug Humanitarian Award.
Letter 5 – Mydas Fly
Subject: What is it?
Location: Pinon Hills, CA
June 22, 2017 5:13 pm
Southern California High Desert against the foothills of Mt. High. June 22, 2017 at around 1pm. I have narrowed it down but am confused and cannot find an exact match to what it is. I have attached pics. Please help. If it’s a mosquito it looks horrendous.
Thank you,
Signature: Tim
Dear Tim,
At first we thought this must be a Bee Fly, but we believe we have correctly identified it as a Mydas Fly, Rhaphiomidas acton, thanks to images on BugGuide. Of the genus, BugGuide indicates the habitat is: “Sandy habitats in relatively arid locales.” Your individual appears to be a female, and we found this image of a male on FlickR. There is also an amazing image of the emergence from the pupa on BugGuide.
Letter 6 – Mydas Fly
Subject: Black, winged, velvety
Location: Sioux Falls, SD
August 4, 2017 11:24 am
I have seen this particular bug in Branson, MO and Sioux Falls, SD. I’ve looked at a lot of “bug” sites but just can’t quite nail this down. The body seems to be “velvety”. I have not determined if it is a stinging insect . What do you say? Thanks for any help you can provide.
Signature: *S*
Dear *S*,
This is a Mydas Fly, Mydas clavatus, and you can compare your image to this BugGuide image to verify our identification. According to BugGuide: “Large black fly with red/orange mark on top (dorsum) of 2nd abdominal segment. Body hairless, cylindrical. Eyes large. Antennae are distinctively clubbed in the Mydidae. This species flies rather boldly in the open. With the black-and-orange pattern, it resembles a wasp and fools the casual observer.”
Thank you for the information. I’ve looked at your suggested site and see that is obviously what we have. Thanks again. *S*
Letter 7 – Mydas Fly
Subject: What is this
Location: Peoria AZ
August 15, 2017 9:56 am
Hi I am trying to figure out what type of insect this is, we have had several of them in and around our pool.
Signature: Thanks Lora
Dear Lora,
Your image is quite blurry, but we believe we have identified this Fly with an orange abdomen as the Mydas Fly Stratiomydas lividus based on this BugGuide image. Of the genus, BugGuide states: “A single species in our area” and it has a range of “AZ to Costa Rica + Peru.”
Letter 8 – Mydas Fly
Subject: What type of bug is this?
Geographic location of the bug: Southern New Jersey
Date: 07/20/2022
Time: 05:50 PM EDT
Your letter to the bugman: Found this very interesting. It’s about a little more than an inch long and has a red bottom.
How you want your letter signed: Not sure
This is a Mydas Fly and here is an image on BugGuide for comparison. According to BugGuide: “Eggs are laid singly in soil or rotting wood. Mydas larvae prey on beetle larvae, esp. those of June beetles. Larvae pupate close to soil (or wood?) surface.” Many people mistake Mydas Flies for wasps, but unlike the latter, Mydas Flies do not sting.
Ed. Note: This posting was rescued after being lost during a recent upgrade.
