What Do Crane Flies Eat? A Quick Guide to their Diet

Crane flies, often mistaken for giant mosquitoes, are unique insects that play a specific role in their ecosystems. You might have spotted these delicate creatures with their long, slender legs and wondered what they eat.

Adult crane flies have a very short life span, typically around one to two weeks. Surprisingly, they do not feed on anything during their adult stage. Their primary purpose is to mate and lay eggs, but they do drink water to stay hydrated. Meanwhile, crane fly larvae, also known as leatherjackets, have a different diet altogether.

These plump, legless leatherjackets are known for their appetite for plant roots and decaying organic matter. They live underground, where they feed on the roots of grasses, crops, and other plants. In gardens and lawns, they can sometimes cause damage by eating the roots of your plants. However, their presence also helps break down the organic matter in the soil, improving its fertility and benefitting other organisms. In any case, it’s important to understand their habits and food preferences to maintain a balanced ecosystem around your home.

What is a Crane Fly?

You might have come across crane flies, also known as mosquito hawks, and mistaken them for mosquitoes. These insects belong to the Tipulidae family and are characterized by their slender bodies and extremely long legs. Let’s dive into some of their distinctive features:

  • Crane flies have wings, with some species having a wingspan of up to 1.2 inches.
  • These insects are equipped with antennae, which aid in their navigation.
  • Their lifespan is relatively short; adult crane flies usually live for a week or two.

Crane flies are often found around water, and despite their nickname “mosquito hawk”, they are not actually related to mosquitoes, nor do they attack them. It’s important to note that crane flies are harmless and do not bite. Their presence in your surroundings is generally not a cause for concern.

One key difference between crane flies and mosquitoes is their appearance. Crane flies have longer legs and a more delicate body structure, making them easy to distinguish from mosquitoes if you take a closer look. So, the next time you see a crane fly, remember that they are interesting insects with their own unique features and pose no threat to you.

Misconceptions About Crane Flies

One common misconception is that crane flies, sometimes called “mosquito hawks” or “skeeter eaters,” prey on mosquitoes. In reality, adult crane flies do not eat mosquitoes or any other insects. They may occasionally feed on nectar and pollen but have a very short-lived adult life and often do not consume anything at all during their lifespan.

Another misconception is that crane flies are giant mosquitoes. While they do have a similar appearance to mosquitoes, they are not related and differ in many ways:

  • Crane flies are larger and have a more slender body
  • Unlike mosquitoes, crane flies do not bite or transmit diseases
  • Crane flies have longer legs, making them appear more fragile

Remember, crane flies are harmless to humans. They do not bite or feed on blood, unlike mosquitoes. So the next time you encounter a crane fly, don’t worry about it being a threat.

In fact, crane fly larvae can actually help reduce mosquito populations. The larvae, known as “leatherjackets,” primarily feed on decomposing organic matter in the soil but may also eat mosquito larvae. This could indirectly aid in controlling the mosquito population in some areas.

To sum it up, these are the key misconceptions about crane flies:

  • They do not eat mosquitoes or their larvae
  • They are not giant mosquitoes and do not bite
  • Their larvae might help reduce mosquito populations indirectly

By keeping these points in mind, you can clear up any confusion surrounding crane flies and their role in the ecosystem.

Life Cycle of Crane Flies

The life cycle of crane flies consists of four stages: egg, larva, pupa, and adult. Let’s take a closer look at each stage to understand their development and feeding habits.

Egg Stage:
Crane flies begin their lives as tiny, oval-shaped eggs. Adult female crane flies lay these eggs near water sources, like streams or wet soil, providing ideal conditions for their hatching and larval growth1.

Larval Stage:
After hatching, crane fly larvae, also known as leatherjackets, emerge. They are small, brown, and have a worm-like appearance2. In this stage, larvae feed on organic matter found in the soil, such as decaying plants, roots, and sometimes other small insects3. The larval stage is crucial for crane flies, as they must consume enough food to store energy for their transformation into pupae.

Pupa Stage:
As larvae mature, they enter the pupal stage, a dormant period in which they transform into adults. They form a gray to brown protective casing called a puparium2. During this time, larval structures break down, and adult structures, such as wings and reproductive organs, form.

Adult Stage:
Finally, adult crane flies emerge from their pupae. These delicate insects have slender bodies, long legs, and a pair of functional wings3. Males and females have different reproductive parts, and they mate shortly after emerging from their pupal stage. Adult crane flies have a short lifespan, and their main purpose is to reproduce and lay eggs, starting the life cycle anew1.

In summary, crane flies have a life cycle consisting of egg, larval, pupal, and adult stages, with each stage having specific habits and purposes. Understanding this life cycle can help you better appreciate these fascinating insects.

Crane Fly Diet

Crane flies are fascinating creatures with a varied diet. As larvae, they typically consume organic materials and plant roots, while adult crane flies primarily feed on nectar and flowers. The difference in diet between the larval and adult stages is essential to understand their impact on the environment and their various roles in the food chain.

Larval stage

At this stage, the crane fly larvae, also known as leatherjackets, primarily feed on:

  • Plant roots
  • Organic materials

Found in the soil, these grubs can sometimes cause damage to turfgrass and other plants. Leatherjackets contribute to breaking down organic matter, aiding the soil’s health and fertility. Their diet may also include decaying leaves and plant matter, which further helps in maintaining a nutrient-rich soil ecosystem.

Adult stage

Once they become adults, the crane flies’ diet shifts to mainly nectar from flowers. This change in diet helps them maintain their energy levels and aids in reproduction. During their short adult lifespan, they are essential in pollinating flowers, focusing their feeding habits on:

  • Flowers
  • Nectar

In some rare cases, adult crane flies might go on to become carnivorous, feasting on small insects like worms to satisfy their hunger. However, this is not common behavior, and crane flies generally stick to feeding on nectar.

To recap, crane flies have different diets at different stages of their lives. In their larval stage, they consume plant roots and organic materials, whereas adult crane flies rely on nectar from flowers. This variety of food sources allows these insects to contribute to a healthy ecosystem, benefiting plants, soil, and other organisms throughout their lives.

Crane Flies and Their Environment

Crane flies are insects that thrive in various habitats, including grassy areas, gardens, and moist soil. In this section, we will explore the environments where they live and the factors that attract them.

Crane flies need a specific set of conditions to flourish. Some of these factors include:

  • Soil: Crane flies prefer moist soil, as it is ideal for laying eggs and developing larvae. Loose, well-aerated soil also helps the larvae to move through it easily.
  • Water: They need a consistent water source for their lifecycle. As a result, you may find them near rivers, ponds, or even in your backyard if you have a water feature.
  • Light: While crane flies don’t have a strong preference for light, their larvae often avoid direct sunlight to reduce the risk of dehydration.

The habitat of crane flies influences their diet and interaction with the ecosystem. Here are some examples of their habitat-related activities:

  • Plants: Crane fly larvae feed on the roots and decaying plant material, while adult crane flies primarily feed on nectar from flowering plants.
  • Garden: If you have a garden with a variety of plants, you might observe crane flies in your outdoor space, as they are attracted to the insects and nectar in the environment.

Crane flies play a role in the ecosystem, where they act as both a predator and prey. For instance, they can help maintain the balance of plant life by consuming decaying matter, while also providing a food source for birds and other predators.

In summary, crane flies thrive in various environments that offer moist soil, water, and a variety of plants. By understanding their habitat preferences, you can better assess their role in the ecosystem and manage their presence in your garden.

Crane Fly Predators and Threats

Different predators and threats exist for crane flies. Birds and bats are common predators that feed on adult crane flies, while skunks and nematodes target their larvae.

  • Birds: A variety of bird species, such as robins and swallows, enjoy eating crane flies due to their size and slow movements.
  • Bats: Bats, with their expert echolocation skills, locate and feast on flying crane flies during their nighttime activities.

However, crane fly larvae can also experience danger. Some examples include:

  • Skunks: These creatures often dig up lawns and gardens searching for tasty grubs, including crane fly larvae.
  • Nematodes: Tiny beneficial nematodes found in the soil can prey on crane fly larvae, helping naturally control their population.

Crane flies face several predators and threats throughout their life cycle, successfully controlling their population in various ecosystems.

Human Interactions With Crane Flies

Crane flies, often mistaken for giant mosquitoes, are actually harmless to humans and pets. They do not bite, nor do they feed on mosquitoes (source). However, crane flies in large numbers can be annoying, especially when they swarm around lighted windows or enter homes as soon as a door opens.

You may find crane flies around your property because they are usually attracted to moist environments. Adult crane flies only live for two weeks at most, and their larvae primarily inhabit aquatic and semi-aquatic habitats (source).

In some cases, crane fly larvae can cause damage to lawns, as they feed on the roots of grass. Their feeding habits can create brown patches in your yard and lead to weakened grass growth. Two species, the marsh crane fly and the common European crane fly, are known to cause such damage (source).

To get rid of these pests, you might want to consider using a pesticide specifically designed for crane fly larvae. Remember to always read and follow the label directions, as improper use of pesticides can harm the environment and pose risks to your family and pets.

  • Pros:

    • Can effectively eliminate crane fly larvae
    • May prevent lawn damage
  • Cons:

    • May harm beneficial insects
    • Poses environmental risks if used incorrectly

In summary, crane flies are mostly harmless creatures that can occasionally be annoying and cause minor damage to your property. However, with proper management and control techniques, you can keep their populations in check and maintain a healthy lawn.

Crane Fly Pest Control

Having issues with crane flies means you’re probably dealing with their larvae, called leatherjackets, which are notorious for damaging grass roots and causing lawn problems. Don’t worry, there are various methods to minimize the impact of these pests on your lawn.

One way to tackle the issue is by using pesticides specifically designed to target leatherjackets. For example, products containing the active ingredient chlorpyrifos can be effective. However, consider the following when using pesticides:

  • Some chemicals can harm beneficial insects or disrupt the ecosystem.
  • Pesticides should be used carefully to avoid harming other organisms or contaminating water sources.
  • Always read and follow the label instructions for proper application.

Another approach is to focus on lawn maintenance to create an environment less conducive to crane fly larvae. To achieve this, try:

  • Regularly mowing and aerating your lawn to improve air circulation and promote healthy roots.
  • Ensuring proper drainage to prevent standing water, which attracts crane flies and creates suitable conditions for leatherjackets.
  • Applying balanced fertilizers to strengthen the grass’s resistance to pests.

Also, consider implementing organic control methods for managing crane fly larvae, such as:

  • Introducing natural predators like nematodes or ground beetles that feed on leatherjackets.
  • Using bacterial treatments like Bacillus thuringiensis that target crane fly larvae without harming other organisms.

Remember to assess your lawn’s condition and choose the most suitable method based on the severity of the infestation and the specific needs of your outdoor space. Keep up with regular maintenance to prevent future infestations, and enjoy your healthy, green lawn!

Conclusion

Crane flies are interesting insects often mistaken for mosquitoes due to their similar appearance, with slender bodies and long legs. However, these slow-flying insects are harmless and have a different diet than mosquitoes.

Understanding their eating habits is crucial to address any concerns regarding them. Crane fly larvae are known to feed on the roots, crowns, and aboveground parts of turfgrass1. However, adult crane flies are commonly found around water and are not considered harmful.

In summary, crane flies play a unique role in their ecosystem, feeding on organic matter and turfgrass. Knowing this can help you deal with various misconceptions and better understand their importance in the environment.

Footnotes

  1. https://extension.oregonstate.edu/catalog/pub/em-9296-managing-crane-fly-lawns 2 3

  2. https://agsci.colostate.edu/agbio/ipm-pests/crane-flies/ 2

  3. https://extension.arizona.edu/crane-flies 2

Reader Emails

Over the years, our website, whatsthatbug.com 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 – Wingless Crane Fly from California

 

Subject:  Wingless Crane Fly?
Location:  Wrightwood, California
March 17, 2015
Found this guy in Wrightwood, California about a week ago.   It moved like a spider but when I picked it up I realized it was not!   It looked line a crane fly to me and a search for “wingless crane fly” brought me to Whatsthatbug..  Most of the images I have seen here and elsewhere  are of much heavier bodied examples with much thicker legs.  I have not found one that looks like this anywhere else but I am fairly sure it is a crane fly.    I’m hoping you’ll find this one as interesting as my son and I did.

I really hope you guys see this.  With all the web resources out there (often your website) I am still stumped!  I have not been able to find an image of anything quite like this.  I am certain it’s a crane fly but all the wingless crane flies I can find online are very grizzly looking.  This one is much different.
Sorry for the filthy hands, we were repairing a sprinkler system.
Kevin

Wingless Insect
Wingless Crane Fly

Dear Kevin,
Thanks for resending this interesting request.  We went back through our unanswered mail and we could not locate your original submission, which is very curious.  Zooming in on your excellent image, we do not believe the antennae and mouthparts are those of a Crane Fly.  It reminds us more of a member of the order Mecoptera, the Scorpionflies.  We are going to seek some additional opinions, including Eric Eaton and Crane Fly expert Chen Young.

Wingless Insect
Wingless Crane Fly

Dr. Chen Young identifies Crane Fly
Hi Daniel,
Yes, it is a crane fly and it is a male crane fly, thus it is probably not in the family Tipulidae, instead it is in the family Limoniidae.  I sure wish I could get a small part of his leg and run a DNA sequence (just a wish till I move to CA).
Thank,
Chen

Close up of curious winged insect
Close up of Wingless Crane Fly

Kevin sends a tardy response:  May 12, 2015
Daniel,
Thanks very much for this.  And sorry for the late response, I replied just after seeing that Dr. Chen gave an ID but I found the reply group of emails in my outbox that never actually sent.  I was very happy to see the crane fly posted and identified.  I wish I could have provided Dr. Chen what he needed for a DNA sequence.  That would have been extra cool.  Thanks again for your fantastic site!

Letter 2 – Crablike Spiny Orb Weaver and Crane Fly

 

Key West creatures.
Can you tell me the correct name of what is locally called a “crab spider” and the proper name of the flying insect also included. These were photographed in Key West, FL. Thanks…
Don Leinbach
P.S. an absolutely brilliant site!!

Hi Don,
Your spider is a Crablike Spiny Orb Weaver, Gasteracantha cancriformis, and the flying creature is a species of Crane Fly.

Letter 3 – Beautiful Crane Fly: Pedicia albivitta

 

Hi…..I took this photo on a bush in my front yard in Michigan’s upper peninsula. I found out it’s a Crane Fly but can you tell me the complete name for it. Thanks,
Ron

Hi Ron,
We contacted Eric Eaton to see if he recognized your species of Crane Fly. Here is his reply: “Well, shoot! I recognize it, but forget which genus it is. There is a picture of one in the photo gallery of the World Catalog of Tipulidae website; also pretty sure there is another image on the Crane Flies of Pennsylvania website, and if not, the webmaster of that site, Chen Young could ID your image. Sorry to refer you on again! Eric ” So, we followed Eric’s lead to The Crane Flies of Pennsylvania and discovered an image of your lovely Pedicia albivitta.

Letter 4 – Crane Flies

 

Subject: ID of 2 insects
Location: Los Angeles, CA
March 28, 2017 1:29 pm
Found this pair this morning in the shade. I assume a male and female. Any ideas?
Signature: Ann Grodin

Crane Fly

Dear Ann,
These are harmless Crane Flies, and we cannot say for certain if they are the same species or if they are opposite sexes.  We can tell you that Crane Flies are currently quite plentiful in our own Mount Washington, Los Angeles garden.  Many species of larval Crane Flies feed on roots of grasses.

Letter 5 – Bug of the Month October 2017: Giant Crane Fly

 

Subject:  What’s this?
Geographic location of the bug:  Missouri
Date: 10/01/2017
Time: 03:49 PM EDT
This guy is on my step. He’s awesome! I would like to know more about him though. Can you help?
How you want your letter signed:  Lacy

Giant Crane Fly

Dear Lacy,
We love your enthusiasm.  This is a harmless Giant Crane Fly,
Tipula abdominalis, and according to BugGuide “adults fly from May to October” and “two generations per year (usually May/June and September/October).”  Your high quality image and your perfect timing has resulted in us naming the Giant Crane Fly our Bug of the Month for October 2017.

Letter 6 – Crane Fly

 

Subject:  New mosquitos in vegas?
Geographic location of the bug:  North Las Vegas, NV
Date: 03/31/2019
Time: 02:13 AM EDT
Your letter to the bugman:  Seen a handful of these over the last couple weeks.
How you want your letter signed:  JB

Crane Fly

Dear JB,
This is a harmless Crane Fly, not a Mosquito.  Crane Flies are often called “Mosquito Hawks” though they do not prey upon Mosquitoes.  The wet winter weather may be contributing to larger numbers of spring Crane Flies this year.

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com 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.

  • 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.

3 thoughts on “What Do Crane Flies Eat? A Quick Guide to their Diet”

  1. I’m homeless and living in Hesperia for the winter. Now that things are warming up (March) I’m seeing the exact same insect, males and females crawling all over the high desert landscape, including on me, which is annoying. I suspected wingless cranefly as well. Is this a truly wi gless species or will it develop wings at some point? What’s the binomial?

    Reply
    • Wingless Crane Flies will not grow wings. Binomial is a two part name (genus and species) that uniquely identifies each and every life form on the plant. The binomial for humans is Homo sapiens.

      Reply

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