Scorpion Fly Life Cycle: A Fascinating Journey Revealed

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Scorpion flies are fascinating insects with a unique life cycle. They capture the interest of scientists and nature enthusiasts alike. In this article, you’ll learn about their intriguing life stages and gain a deeper appreciation for their existence.

The life cycle of a scorpion fly starts with eggs laid by the female. Once hatched, the young larvae go through a period of growth and development, during which they molt multiple times. These phases, known as instars, allow the scorpion fly to grow into an adult.

As an adult scorpion fly, you’ll find them seeking mates, laying eggs, and providing fascinating opportunities for observation in their natural habitats. With this knowledge, you can now explore and appreciate these amazing insects even more.

Scorpion Fly Basic Information

Scorpion flies, belonging to the Mecoptera order of insects, are a fascinating group of species. They have distinct characteristics that set them apart from other insects.

You might be interested to know that scorpion flies are named so due to their unique appearance. Their elongated, curved abdomens resemble a scorpion’s tail. Despite the name and intimidating look, these insects are harmless to humans.

An important aspect of scorpion flies is their life cycle. It undergoes four main stages:

  • Egg: A female scorpion fly lays her eggs in the soil or leaf litter.
  • Larva: The larvae resemble caterpillars, feeding on decaying plants and small insects.
  • Pupa: Scorpion fly larvae pupate in a cocoon before metamorphosing into adults.
  • Adult: Adult scorpion flies have a short lifespan, usually lasting a few weeks.

Some fascinating features of scorpion flies include:

  • Long, beak-like mouthparts for feeding on dead or dying insects and nectar
  • Large, compound eyes improving their vision for mating and navigation
  • Well-developed wings aiding in their agile flight

Mecoptera contains various species, with distinct appearances and features. Often, they are grouped into three main types based on their tail appendages:

  1. Panorpidae: Resembling scorpions, with upturned, stinger-like tails
  2. Bittacidae: Also called hangingflies, with elongated bodies and tails lacking a stinger-like appearance
  3. Meropeidae: A rare family, with only one known species in North America and no pronounced tail appendage

In summary, scorpion flies are unique insects with an interesting life cycle and diverse species. Their distinct features and appearance make them worth studying further.

Scorpion Fly Appearance

Body Structure

Scorpion flies, belonging to the genus Panorpa, are moderate-sized insects with a body length of about 3/8 inch1. Their body consists of three main parts: the head, thorax, and abdomen2. The head houses their compound eyes and elongated beak, while the thorax supports four long wings and three pairs of legs3. The abdomen contains the digestive and reproductive systems4.

Distinctive Features

Scorpion flies have a few distinctive features that make them stand out from other insects:

  • Beak: Scorpion flies have a long beak-like structure, which extends from their head and houses their chewing mouthparts5.

  • Wings: Their wings are typically yellowish-brown with black bands or spots6. At rest, they hold their wings in a V position7.

  • Male abdomen tip: Males have an abdomen tip that looks like a scorpion’s stinger due to their modified genitalia8. This curved “tail” may look intimidating but is completely harmless9.

Scorpion Fly Life Cycle

Egg Stage

During the Egg Stage, female scorpion flies lay their eggs in moist habitats such as soil and moss. This provides a safe and nurturing environment for the eggs to develop.

Larval Stage

The Larval Stage starts when the eggs hatch into larvae, which resemble small caterpillars. These larvae typically live in mosses and leaf litter, where they continuously feed on decaying plant matter to grow and develop. Your choice of habitat should consist of:

  • Mosses
  • Leaf litter
  • Decaying plant matter


In the Pupation stage, the scorpion fly larvae form a protective case called a pupa. The pupa, concealed within the habitat, provides a secure environment for the larvae to metamorphose into adults. Factors to consider during this stage include:

  • Suitable habitat
  • Pupa protection
  • Metamorphosis duration

Adult Stage

The final stage in the life cycle is the Adult Stage. Once the scorpionflies emerge from their pupae, they begin searching for mates. Males, with their distinct genitalia, use it to attract females for mating. It’s essential to note:

  • Mating behavior
  • Male and female appearance
  • Lifecycle completion

Following the given instructions and providing necessary information within the second-person point of view and a friendly tone, remember to keep it brief, well-organized, and with relevant examples when needed.

Scorpion Fly Diet

Scorpion flies primarily consume dead insects, making them an important part of natural decomposition. They help keep ecosystems clean by feeding on these insect carcasses. Some scorpion flies also feed on nectar, plants, and pollen, which adds an element of diversity to their diet.

Fruits are another part of a scorpion fly’s diet. When fruits begin to decay, a scorpion fly can be found feasting on them to fulfill its nutritional needs. You may find these tiny insects hovering around garden patches.

Scorpion flies are also known for preying on soft-bodied insects. They use their long, beak-like mouthparts to inject saliva into their prey, breaking down their victim’s internal structures before consuming them. A few examples of prey include aphids and caterpillars.

To help you understand how scorpion flies differ in their diet according to the food they consume, here’s a comparison table:

Food Source Scorpion Fly’s Role
Dead Insects Decomposers
Nectar Pollinators
Plants Herbivores
Pollen Pollinators
Fruits Frugivores
Soft-bodied Insects Predators

In summary, scorpion flies have a diverse diet that consists of dead insects, nectar, plants, pollen, fruits, and soft-bodied insects. This variety in their feeding habits benefits their environment by supporting natural decomposition, pollination, and pest control.

Scorpion Fly Behavior

Scorpion flies exhibit unique behaviors, especially in their mating rituals. They use pheromones to communicate with potential mates and engage in fascinating practices.

When a male scorpion fly finds a suitable female, he releases pheromones to attract her. These chemical signals are vital in the mating process as they assist in identifying compatible partners.

Once the female approaches, the male performs an intricate mating ritual. This typically involves wing flapping and other body movements. The goal is to impress the female and earn her acceptance for mating.

During sperm transfer, the male uses its abdomen to deposit a sperm packet called a spermatophore. This is an efficient method, ensuring successful reproduction.

Scorpion flies also serve as natural pest control agents. They feed on dead insects and help keep the ecosystem balanced.

To summarize, scorpion fly behavior includes:

  • Using pheromones for communication and mate attraction
  • Performing complex mating rituals
  • Transferring sperm via spermatophores
  • Acting as natural pest control agents

Remember, when observing these fascinating creatures, always respect their habitat and allow them to thrive in their natural environment.

Scorpion Fly Ecology

Habitat and Distribution

Scorpion flies, belonging to the genera Bittacus and Hylobittacus, are fascinating insects found in a variety of habitats. These insects prefer marshy areas and cool environments, often near vegetation. For example, you might find them near:

  • Woodlands
  • Streams
  • Dense shrubs

These habitats provide ample vegetation for scorpion flies to thrive since it helps them maintain a cool living environment.

Predators and Threats

Scorpion flies, like many other insects, face various threats from predators in their ecosystem. Some of their common predators are:

  • Spiders
  • Birds
  • Larger insects

Among the scorpion fly species, Snow Scorpionflies are particularly vulnerable to predators due to their small size and limited mobility in cold environments.

To protect themselves from predators, scorpion flies employ multiple defensive strategies like:

  • Camouflage: their coloration helps them blend into their surroundings
  • Swift flying: their large wings allow them to escape quickly

In conclusion, understanding scorpion fly ecology gives you valuable insight into their habitat, distribution, and predator interactions.


  1. Common Scorpionflies | Department of Entomology

  2. Ibid.

  3. Ibid.

  4. Ibid.

  5. Ibid.

  6. Common Scorpionflies | Missouri Department of Conservation

  7. Ibid.

  8. Ibid.

  9. Ibid.

Reader Emails

Over the years, our website, has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Insects found in the Snow: Snow Scorpionflies and Fungus Gnat


snow bugs
Dec 10, 2010
December 10, 2010 11:37 am
I really tried to identify the 3 bugs on the snow I sent 12/1/10. At least I went thru your website and bugguide… I’m thinking you haven’t had much luck either. The one looks like a mini cranefly to me and I thought the other 2 were springtails, but they were solitary critters, and they are all wrong anyway! Any website suggestions I might peruse further? I can’t believe how addicted to bugs I’ve become since I found your website looking for an aquatic larvae! Never found the exact one, but I’m pretty sure it was some kind of beetle. Love your site and thanks for doing so much so well.
Signature: Cathy Schabloski

I wouldn’t be nekkid out here…
Location: Tonasket WA, near Canada
December 1, 2010 4:43 pm
Amazing what is out on the snow, and so very tiny and frail! I found 3 different kinds today. It’s about 32F now, and last week it was -12F. I think this one is a type of springtail, but had no luck with the other 2. I left them for you to crop as I feared loss of whatever resolution there is.
Signature: Cathy

Snow Scorpionfly

If I had wings, I’d fly south
Location: Tonasket WA near Canada
December 1, 2010 5:02 pm
Sorry, couldn’t find her, she’s about 2mm long. Why do I think she’s a she? I’ts 32F here and was -12F last week. Do I have no more sense than a bug? Actually, we both must love it here! And I know if this bug knew about your site it would love it as much as I do and be in awe of all you do. Thank you everyone that helps.
Signature: Cathy

Fungus Gnat

ovipositer? snow?
Location: Tonasket WA near Canada
December 1, 2010 5:21 pm
I’m just guessing here, maybe a type of springtail? only 2mm or so. Who would believe something this small at 32F and last week it was -12F. Where do the eggs/larvae/babies hang out until it gets warm(!) enough to come out and play? I saw 3 differnt kinds today. I am constantly amazed, both at the world around me and what y’all do out of the goodness of your hearts and the love of bugs.
Signature: Cathy

Snow Scorpionfly in the genus Bores

Dear Cathy,
We apologize profusely.  We wrote you back the day after you sent the three snow insects and we indicated we would research you insects and post them.  We forgot.  It is the end of the semester and work is piling up and we failed to deliver.  We can tell you that none of your insects are Springtails, be we still need to research them.  The one you believe to be a Crane Fly is some species of fly, and we believe it may be a Gnat.   At least we have posted your photos and as we research, we would gladly welcome any input our readership may provide.  You might want to post a comment to the posting and you will be notified in the future if any experts are able to provide any information.

Update and Correction: Snow Scorpionfly perhaps
Hi again Cathy,
We believe the insect with the ovipositor may be a Snow Scorpionfly in the genus
Boreus.  You can check the Crane Flies of Pennsylvania website to compare the image of a female posted there.  BugGuide also has information on the Snow Scorpionflies in the genus Boreus including this description:  “Adults dark-colored with an elongated rostrum (“beak”), long antennae, vestigial wings, and long hind legs adapted to jumping; female has a straight ovipositor about the same length as the rostrum, and tapering to a point; males have a blunt rounded abdominal tip“.

Chen Young provides identifications
December 12, 2010
Good morning Daniel,
The two wingless images are not crane flies instead, they are Snow Scorpionflies in the genus Boreus, family Boreidae and order Mecoptera   I provided some short comparison in the crane fly website here for your informaiton
The fly with wings is a Fungus Gnat in the family Mycetophillidae.
Have a happy and safe holiday season.

December 12, 2010
I had just come to the same conclusion about the scorpionflies, thanks to your recommended website. I wish I had had my camera today because I got to see the forked projections on the backside of the male, they can raise and fold them back down flat, and he has a sort of single “Mercury wing” coming off the back of his head. Thank you and Chen so much for your help.  Daniel, you certainly don’t need to apologize to me for being busy and forgetting a few things! Thank you again.

Update:  Fungus Gnats can survive subzero conditions.
February 10, 2011
fungus gnat
February 10, 2011 7:58 pm
On 12/1/10 I asked you to identify what turned out to be a fungus gnat and male and female scorpion fly. I looked up the scorpionfly fly right away, probably because of the name… and found the heat of your hand can kill them! Well, I just looked up fungus gnat, and I don’t know if the one I read about is my exactr same one, but this tiny delicate thing can go to -60 and the abdomen freezes, but not the head! It will survive to -100. Here’s the website, I’ve always liked bugs, but you and all your contributors have given me a new fascination for all of it! Thank you so very much.“
Signature: Cathy Schabloski

Thanks for the link and information Cathy.  This is fascinating.

Letter 2 – Hangingflies from Australia Courting and Mating


Scorpionfly mating sequence

Hangingfly with Fly Prey

Scorpionfly mating sequence
November 16, 2010
Location:  Australia
Hi Daniel,
Hope you like this sequence.
The male had to wait for less than a minute with his robberfly for a female to arrive. When she did, he started to make what we would call beckoning motions, by repeatedly curling and uncurling one rear claw. All the time he slowly moved his abdomen into position for mating. When he locked with her she immediately let go of the grass and started to thrash around, at which time he passed her the fly and she settled in to dine while he went about his business. After mating her grabbed the fly back and took off, probably to use it for his next conquest, the cad.

Hangingflies Courting

Hi Trevor,
This series is phenomenal, and your firsthand observations are priceless.

Hangingflies Mating

We wonder if there are other observational accounts of the male absconding with his nuptial gift after getting his way.

Hangingflies Mating

Letter 3 – Hangingflies: Mating Ritual


Scorpionfly mating ritual
Hi Daniel,
after sending of the last email I got to thinking whether the image may still be in a sent mail folder, guess what, I found it.
So attached is the full frame just resized down 50% so you can crop as desired.

Hangingflies: Mating Ritual

Hi again Trevor,
Thank you so much for contributing this wonderful image to our site.  The male Scorpionfly in the family Bittacidae, the Hangingflies, often present the females with a nuptial gift of a captured insect to entice her into mating.  The male Hangingfly in your photograph has such a gift.  Again, thanks so much for responding to our earlier request and for contributing so many wonderful images of Australian Hangingflies to our site.

Letter 4 – Hangingfly Captures True Bug in Australia


Scorpionfly in active hunting sequence

Hangingfly captures Bug

Scorpionfly in active hunting sequence
November 22, 2010
Location:  Australia
Hi Daniel,
Because of the file size and the hassles I am having with my net connection lately I thought I would email this sequence to you rather than try and use the form. Yesterday I spotted a male trying to wrestle a large moth free of its grip but by the time I got the camera the moth had escaped it. Today I found this one making strenuous efforts to get this true bug nymph free from its grip on a grass stem. It took a while but eventually it managed to pry all its feet loose and fly off with it. I didn’t realise they were active hunters as well as ambush predators.
Feel free to slice up the image or use it whole if you want.

Hangingfly Captures Bug

Hi Trevor,
Thanks for your continued documentation of this Australian species of Scorpionfly, known as a Hangingfly, as it hunts and mates.  For size consideration, we did split up your montage, and six parts might have been preferable to three parts, but we were interested in the time constraint that would entail.  Clicking on the image will produce an enlarged version.

Hangingfly Captures Bug

Letter 5 – Nocturnal Ichneumon, NOT Scorpionfly


Subject: Winged bug with a hard exoskeleton
Location: Suburban Philly, PA
April 7, 2014 11:53 am
Hi bugman! I’ve seen several of these bugs since moving into my apartment in suburban Philadelphia in 2007, although I usually find them dead under the TV stand. This guy, and one of his relatives a few days before, were alive. His relative was on my screen door at night (attracted to the light, maybe?) and was a lighter yellow color, while this guy is darker and managed to make it inside to the front window. After I snapped this photo he started flying around torturing my cat, so I whacked him with a flip-flop (I’m sorry! I don’t usually kill) and he had an incredibly hard exoskeleton – all my weight didn’t kill him. If he’s not dangerous, I’m content to try and catch them and put them outside if I ever find any more. Do you know what he is? We’ve had typical spring weather for the last few days – cool at night, warmish and alternating between damp and sunny during the day. Some of them (not this guy, but others) look like th ey have a large stinger.
Signature: Colleen

Possibly Scorpionfly
Nocturnal Ichneumon

Dear Colleen,
We are not certain of the identity of this insect, but our best guess is a Scorpionfly or other member of the order Mecoptera.  It looks somewhat like this member of the family Panorpodidae that is pictured on BugGuide.  We will try to get another opinion.

Eric Eaton provides a correction
That is one of the nocturnal ichneumon wasps.  Not enough detail to place to subfamily, let alone genus, species.

Thank you SO much! A quick Google search of Ichneumon wasps makes me think Eric was right. Good to know that’s an ovipostor and not a stinger. Looks like my kitty cat is safe 🙂 Again, thanks – I didn’t expect such a quick reply!


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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Tags: Scorpion Flies

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6 Comments. Leave new

  • I had just come to the same conclusion about the scorpionflies, thanks to your recommended website. I wish I had had my camera today because I got to see the forked projections on the backside of the male, they can raise and fold them back down flat, and he has a sort of single “Mercury wing” coming off the back of his head. Thank you and Chen so much for your help. Daniel, you certainly don’t need to apologize to me for being busy and forgetting a few things! Thank you again.

  • I am involved in writing an Animal Behavior textbook that will be published by Oxford University Press USA. I am seeking permission to reprint your three images of a hangingfly transferring a nuptial gift to a female.
    Thanks in advance for your help.


    • Hi Tom,
      Trevor from Australia contributed these images and we will gladly contact him regarding permission to use his images. We reserve the right to reproduce content from our website in approved publications, but whenever it is possible to contact the photograph copyright holder, we always defer permission. We will contact Trevor with your request.

  • Hi Daniel,
    Thanks for letting me know about Tom’s request. Happy for him to single use the photos in his book as per my email.

  • heyyyy….bless your little bug observant hearts. now I can refuse to take lip off those morons who give me the stink eye when I tell them we have gnats in/on our snowbanks. And they BITE. I have one little hound with tender skin who is getting chewed UP by these things. please respond if you have observed similar.


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