Crane Fly Life Cycle Explained: Discover Their Fascinating Journey

Crane flies, often mistaken for giant mosquitoes, are delicate insects with a unique life cycle. They belong to the family Tipulidae and are members of the order Diptera, which means they have two wings and a pair of specialized smaller wings called halteres 1.

While adult crane flies are mostly harmless and can be found near water sources, it’s their larvae, commonly known as “leatherjackets,” that can cause damage to lawns 2. The life cycle of a crane fly begins when the adult lays its eggs in water or moist environments, such as leaf litter or soil 3.

Crane Fly Life Cycle Stages

Eggs

The life cycle of a crane fly begins with eggs laid by the adult females. These eggs are typically deposited either underwater or in the soil near water sources, which provides the larvae with ideal moisture levels for their growth and development 1.

Larvae

Crane fly larvae, commonly known as “leatherjackets,” are aquatic or semi-aquatic creatures that can be found in streams, lakes, and moist environments such as leaf litter or ditches 2. They are known for their voracious appetite, feeding on organic matter and decomposing leaves. In some cases, they can also cause damage to grass roots in lawns 3. The larval stage lasts for several months, during which they grow and molt several times.

Pupal Stage

After the larval stage, crane flies enter the pupal stage, during which they undergo metamorphosis. During this phase, the larvae create a protective casing known as a puparium to shelter themselves while they transform into adults. This stage is relatively brief, lasting only about one to two weeks.

Adult Crane Fly

The final stage of the crane fly life cycle is the adult form. Adult crane flies resemble giant mosquitoes, but they are actually harmless and do not bite or transmit diseases. They have long, delicate legs and a wingspan that can reach up to 1.2 inches 4. Their primary goal as adults is to reproduce, and they typically only live for a few days to a week.

Comparison of life cycle stages:

Stage Duration Characteristics
Eggs A few days Deposited near water sources
Larvae Several months Aquatic, feed on organic matter
Pupal Stage 1-2 weeks Metamorphosis occurs
Adult Days to a week Reproduction, short lifespan

Crane Fly Habitats and Feeding

Streams and Marshes

Crane flies are commonly found around water sources such as streams and marshes. In these habitats, they play an essential role in the ecosystem. Crane fly larvae, also known as leatherjackets, feed on organic matter like decaying leaves. Adult crane flies are harmless and generally don’t feed at all, with some species occasionally feeding on nectar.

Lawn and Turfgrass

In North America and Europe, crane flies can also be found in lawns and turfgrass. Leatherjackets can cause significant damage to these areas, as they feed on the roots, shoots, and crowns of the grass. This kind of damage is especially apparent in early spring. To prevent such damage, simple lawn maintenance and irrigation practices can be employed.

Forage Crops

Some crane fly species can also be found in forage crops across North America, British Columbia, and Washington. Here, they can also cause damage to crop roots and compromise plant health.

Features of Crane Fly Habitats:

  • Presence of water sources
  • Organic matter for larvae to feed on
  • Grass or crops for larvae to damage

Characteristics of Crane Fly Feeding:

  • Larvae feed on roots and organic matter
  • Adults don’t feed, or occasionally feed on nectar
  • Damage mostly occurs in lawns and forage crops
Habitat Larval Feeding Adult Feeding Damage Potential
Streams/Marshes Organic matter None or nectar Minimal
Lawn/Turfgrass Grass roots, shoots, crowns None or nectar Substantial
Forage Crops Crop roots None or nectar Moderate

Crane Fly Classification and Diversity

Tipulidae Family

Crane flies belong to the Tipulidae family within the order Diptera. They are often mistaken for mosquitoes, but their similarities end at the superficial mosquito-like appearance. Crane flies are sometimes called mosquito hawks, despite being harmless to humans and not feeding on mosquitoes.

Some characteristics of the Tipulidae family include:

  • Slender, mosquito-like body
  • Extremely long legs
  • Slow-flying and usually found around water

Subfamilies and Species

There are two main subfamilies within the Tipulidae family: Cylindrotominae and Limoniinae. These subfamilies consist of several species, totaling to hundreds of species of crane flies in North America.

Comparison of subfamilies:

Subfamily Number of Species Appearance Habitat
Cylindrotominae Several species Similar slender body to Limoniinae, but with more distinct and elongated wings Around water, with aquatic larvae
Limoniinae Numerous species Characteristic long legs, slender body, and mosquito-like appearance Terrestrial, often found around water

Examples of crane fly species within these subfamilies vary in size, color, and preferred habitats. Many species have unique features that help them adapt and survive in their environment.

Physical Characteristics and Identification

Appearance

Crane flies are delicate-bodied insects, often mistaken for giant mosquitoes due to their slender bodies. They can be found in various colors, including tan, gray, and greenish shades, with a definite head and tiny, fleshy projections at the hind end.

Wingspan

Adult crane flies have one pair of wings, which they often hold out at a 45-degree angle to their bodies. Their wingspan varies across species, but it is significant for their body size, helping them in slow flying.

Long Legs

One distinguishing feature of crane flies is their extremely long legs. These legs make them appear even more mosquito-like, but they also contribute to their weak flying ability.

Here is a comparison table of crane flies and mosquitoes:

Feature Crane Fly Mosquito
Body Size Larger than mosquitoes Smaller
Legs Length Extremely long legs Shorter legs
Wings One pair, held at 45-degree angle One pair, not held at an angle
Biting Not bloodsuckers Bloodsuckers

Some key physical traits of crane flies include:

  • Slender bodies resembling giant mosquitoes.
  • One pair of wings held at a 45-degree angle.
  • Extremely long legs, contributing to weak flying abilities.
  • Tan, gray, or greenish body colors.

Predators and Pest Management

Biological Control

There are several natural predators that help control crane fly populations. Examples include:

  • Birds: They feed on crane fly larvae and help limit their numbers.
  • Spiders: Many spider species prey on adult European crane flies, reducing the nuisance they cause.
  • Bats: These nocturnal mammals consume adult crane flies, keeping their population in check.
  • Daddy longlegs: These insects, also known as harvestmen, prey on crane fly larvae and contribute to their biological control.

Chemical Control

Chemical control can also be employed to manage crane fly populations and reduce lawn damage. However, it’s essential to consider the pros and cons before using insecticides.

Pros:

  • Effective against crane fly larvae and adults.
  • Can prevent damage to turfgrass caused by larvae feeding.

Cons:

  • Possible risk to non-target organisms.
  • Potential for overuse, leading to resistance in crane fly populations.
  • Negative environmental implications.

When considering chemical control for crane fly management, it’s worth comparing two common insecticides:

Insecticide Pros Cons
A Effective on larvae, limited environmental impact May not be effective against all crane fly species
B Broad-spectrum action, rapid results Higher environmental risks, possible harm to non-target species

Proper turfgrass management strategies, such as regular fertilization and irrigation, can help maintain healthy lawns and limit damage caused by crane fly larvae. Implementing integrated pest management principles is crucial for balancing ecological concerns and controlling crane fly populations effectively.

Crane Fly Impact on Ecosystem and Human Environment

Crane Fly Nuisance

Crane flies, often called “mosquito hawks,” are true flies that resemble giant mosquitoes. Despite their intimidating appearance, adult crane flies are harmless to humans and have a short lifespan of only about two weeks. Contrary to popular belief, they do not feed on mosquitoes but rather consume nectar.

Crane flies might be seen as a nuisance to some because they often invade homes and can be found around water sources. Additionally, their larvae have some negative effects on lawns, as they feed on the roots of grass, ultimately causing damage.

Crane Fly Impact on Lawns

Crane fly larvae, also known as leatherjackets, can damage lawns by feeding on the roots and shoots of grass. They spend most of their time underground, making them difficult to detect. Here are some key features of crane fly larvae:

  • Grey-brown cylindrical bodies
  • Fleshy lobes on the posterior end
  • Often found in cool, wet environments

These lawn pests may attract predators like skunks, which can further damage lawns while searching for larvae to eat. Different crane fly species may have a varying number of generations per year, with some having multiple generations, while others only have one generation a year.

To minimize damage caused by crane fly larvae, it’s important to follow proper lawn maintenance and irrigation practices, like:

  • Keeping grass height at a moderate level
  • Avoiding overwatering
  • Aeration to reduce soil compaction

Taking these steps will help maintain a healthy lawn ecosystem and reduce the impact of crane fly larvae. Crane flies have been a part of the ecosystem since the Barremian, a period in the early Cretaceous, and have adapted to various environments. Understanding their impact on both the ecosystem and human environment is essential in mitigating the negative effects they might cause.

Interesting Facts and Myth-Busting

Crane Fly vs. Mosquito Hawk

  • Crane flies and mosquito hawks are often confused due to their similar appearance.
  • They have slender bodies and long legs, but actually belong to different insect families.

Crane flies are harmless insects that don’t bite or transmit diseases. They are commonly found around water and feed on nectar as adults. Some people mistakenly call crane flies “mosquito hawks” or “skeeter eaters,” but they don’t prey on mosquitoes. Mosquito hawks, however, are a type of dragonfly that does eat mosquitoes.

Comparison table:

Feature Crane Fly Mosquito Hawk
Body Slender Sturdier
Legs Extremely long Long but sturdy
Wingspan Up to 1.2 inches Longer
Preys on mosquitoes No Yes
Adult diet Nectar Mosquitoes and other small insects

Crane Fly vs. Daddy Longlegs

  • Crane flies and daddy longlegs are also mistaken for one another due to their appearance.
  • Both have long, thin legs, but are different types of arthropods.

Crane flies belong to the fly family (Tipulidae), while daddy longlegs, also known as harvestmen, are arachnids in the order Opiliones.

Comparison table:

Feature Crane Fly Daddy Longlegs
Body type Insect, slender Arachnid, oval
Legs 6, extremely long 8, long
Wings 2, easily visible None
Diet Adult: nectar, Larvae: roots & decaying plants Decomposing organic matter and small insects

Crane fly larvae are known to cause damage to grass by chewing through patches of lawn, affecting crowns and roots. This can be managed with proper lawn care practices such as mowing and timely irrigation. The Pacific Northwest region has seen an increase in crane fly populations recently, but raccoons are attracted to the larvae as a food source, helping to control their population.

Pest management options:

  • Mowing your lawn regularly
  • Proper irrigation
  • Nematodes as a biological control agent
  • Removing hiding places for crane fly larvae

Keep in mind that the crane fly’s pest status varies depending on the insect species and region. Not all crane flies are invasive or damaging to lawns, so always identify the specific species in your area before taking action. Remember, their life span as adults is short, and they typically pose little threat to humans or pets.

Scientific Classification

The crane fly belongs to the kingdom Animalia, phylum Arthropoda, class Insecta, suborder Nematocera, and the superfamily Tipuloidea. Let’s examine some features of crane flies’ life cycle and characteristics to better understand these unique insects.

Crane fly larvae, also known as leatherjackets, are tan, gray, or greenish grubs with a plump, segmented body. They’re found in moist soil, where they feed on organic matter like decaying plants and roots.

Survival of crane fly larvae relies on moisture in their environment. In fact, proper lawn care and irrigation practices can help prevent crane fly damage to your grass.

Some crane fly features include:

  • Brownish body color for adults
  • Long legs
  • Slow-flying capabilities

Diet is an important aspect of the crane fly life cycle. While adult crane flies mainly consume nectar or do not feed at all, larvae consume plenty of decaying plants and roots as mentioned earlier. This difference in diet can lead to varying levels of damage caused by crane flies, especially in their larval stage.

To sum up, the scientific classification of crane flies is:

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Suborder: Nematocera
Superfamily: Tipuloidea

In conclusion, understanding the scientific classification of crane flies and their unique features can provide valuable insights to better manage their potential damage and appreciate their role in the ecosystem.

Crane Fly in Literature and Popular Culture

Crane flies are often mentioned in literature due to their unique appearance and behavior. For example, they feature in the poem Bittacomorpha, which focuses on their delicate movements while flying.

In popular culture, crane flies are sometimes mistakenly believed to be giant mosquitoes, which can lead to misconceptions about their diet and behavior. However, these insects do not bite or feed on blood.

  • Literature: Poems and other literary works often mention crane flies as symbols of fragility or grace.
  • Dictionary: Dictionaries include crane flies, defining them as large, slender, long-legged insects that resemble giant mosquitoes.
  • Lists: Crane flies are commonly found on lists of insects that resemble or are mistaken for mosquitoes.

A comparison table to highlight some differences between crane flies and mosquitoes:

Feature Crane Fly Mosquito
Size Larger Smaller
Legs Very long legs Shorter legs
Diet Larvae feed on decomposing matter, adults do not feed Females feed on blood, males feed on nectar

Some misconceptions about crane flies:

  • They bite humans (false)
  • They feed on mosquitoes (false)

In conclusion, crane flies are unique insects that have found their way into literature and popular culture, often due to their appearance and the misconceptions surrounding their behavior.

Footnotes

  1. Crane Fly Larvae – MDC Teacher Portal

  2. Crane Fly Larvae – MDC Teacher Portal

  3. Managing Crane Fly in Lawns – OSU Extension Catalog

  4. Crane Flies – The University of Arizona

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 – Giant Western Crane Fly

 

What is this bug??
I took this photo in july ’05 in the Puget Sound are of Washington state. It was on the side of my house and was about2.5" across at the legs.Thank you for the I.D. -Lynne

Hi Lynne,
This is a Giant Western Crane Fly, Holorusia rubiginosa. It is harmless. This is the biggest fly west of the Rockies.

Letter 2 – Great Big Cranefly

 

Identification
I found this guy while fishing for brown trout near a little spring feed creek in Southwest Michigan (8/30/04). The creek has dense tree cover over it. This guys was on a telephone pole by the road. The body was about three to four inches long and with it’s legs it outstretched, it was easily as big as my hand. It seems like a bigger version of a crane fly. I suspect the trout probably feast on these guys when they are in their emergent phase? Here is a couple images. Thank you.
Russ

Thanks Russ,
I can’t give you an exact species name, but you do have one of the larger Craneflies from the Family Tipulidae. The insect is nicely camoflauged against the dead wood. You are probably right that they make good trout food. They are sometimes thought to be giant mosquitos, but they are in fact harmless to man.

Letter 3 – Great Western Crane Fly Roadkill

 

Subject: Large winged insect in car grill
Location: Western Washington
July 27, 2013 3:03 am
I apologize for the nature of the picture, and know it can be tough to identify an insect that has been mangled in this fashion, but was wondering if you could give me any clues to its type. It was found yesterday morning on my sister’s car, she had come back late one night & did not notice it til the next morning. I didn’t know until later, or I would have taken it off to try to ID it myself or at least get some more pictures, and unfortunately it detached on her way to work. We’re in the Seatac area, she works in Tacoma, if that helps at all. Any help you can provide would be appreciated, thanks in advance!
Signature: Mike

Great Western Crane Fly struck by car
Great Western Crane Fly struck by car

Hi Mike,
This appears to be a Great Western Crane Fly,
Holorusia hespera, and we are pretty certain it is the largest Crane Fly in western North America.  Here is a photo on BugGuide for comparison.

Letter 4 – Giant Eastern Crane Fly

 

Subject: African jewelery-like bug
Location: becket, ma
August 27, 2014 10:41 am
Hi there! Awesome website, excited that I can possibly learn the name of this bug. It’s sitting on someone’s finger.
Signature: katy

Giant Crane Fly
Giant Eastern Crane Fly

Dear Katy,
The pattern on the wings and body of this Giant Eastern Crane Fly does look vaguely African.

Letter 5 – Metamorphosis of a Crane Fly

 

Subject: What’s going on here?
Location: SW Virginia
July 31, 2015 10:39 am
What is this interesting insect? We spotted it in a flower pot and filmed it emerging from a caterpillar or pupa. (See https://www.youtube.com/watch?v=e6hoz8cytRU). It’s about an inch long. Thanks!
Signature: Curious

Metamorphosis of a Crane Fly
Metamorphosis of a Crane Fly

Dear Curious,
Your images of the metamorphosis of a Crane Fly in the family Tipulidae are a very exciting addition to our archives.  Crane Flies do not bite despite their resemblance to giant Mosquitoes.

Newly emerged Crane Fly
Newly emerged Crane Fly

 

Letter 6 – Giant Eastern Crane Fly

 

Subject: not a crane fly?
Location: Rockland, Ontario
August 24, 2015 3:33 pm
Hi, my uncle lives in Rockland Ontario and we found tyis large mosquito looking bug. Beautiful but i cant identify it.
Signature: Chris Brabant

Giant Eastern Crane Fly
Giant Eastern Crane Fly

Dear Chris,
This is certainly a Crane Fly, more specifically, a Giant Eastern Crane Fly,
Pedicia albivitta, which is profiled on BugGuide where it states:  “This species is one of the largest in northeastern United States and Canada.”

Letter 7 – Giant Eastern Crane Fly

 

Subject: Giant Eastern Crane Fly
Location: Washington, Pennsylvania
September 28, 2015 1:03 am
I found an interesting bug in my dogs water bowl and i had no idea what it was until i found it on your site. I wanted to share the photo of the Giant Eastern Crane Fly! This is the first time I’ve ever come across one of these beauties, and let me just say, I’m very glad to know it’s harmless!
Signature: Jessicarenae

Giant Eastern Crane Fly
Giant Eastern Crane Fly

Dear Jessicarenae,
You are correct that this is a Giant Eastern Crane Fly,
Pedicia albivitta, and the stark white background in your image nicely illustrates the lovely markings on the wings of this species.

Letter 8 – Swarming Crane Flies

 

Subject: Large insect swarm… is my Infant Safe?
Location: Pacific Northwest, Springfield, Oregon
April 17, 2017 3:15 am
Hello, I have a 17 yr old Son and 5 Month old Son at home. My Oldest was working on the yard this weekend. We had a tree fall during a storm about 10 years ago. He was starting to use the Weed-eater around the stump. When a Swarm of these insects flew out at my Son. He didn’t get stung and as fast as they surrounded him they went back in. He said they acted like wasps but they didn’t follow him. I though at first he was just trying to get out of yard work. When I went out there I saw one until I got to close and 20 of them flew out. My son was right they acted like wasps more like pretended to be. I went and grabbed the camera with the long lenses to take the picture. They are very Beautiful but intimidating. I would like to know what they are and if they are safe? Especially because of my 5 month old. The stump is about 6 ft from the Nursery Window. They window is closed now but when summer comes that might be a problem. I don’t want to harm them if we can co-exist I will leave them be. If not are they able to be relocated?
Thank you for taking the time to read this and Thank you in advance for any help you can give me!
Signature: Angie W

Crane Fly

Dear Angie,
We believe we have correctly identified this beautiful, and perfectly harmless, male Crane Fly as
Ctenophora vittata angustipennis thanks to images posted on BugGuide where Eric Eaton provided this comment:  “There is at least one common wood-boring species in the Pacific Northwest. I ran across a log full of the larvae and pupae once, before I knew what they were! Pretty bizarre.”  According to BugGuide, there are two subspecies:  “holarctic: one ssp. along the NA Pacific coast (BC-CA), another across Eurasia.”  We believe the larvae were developing in the rotting wood and that is why they were found near the log.  They are not social insects, but when conditions are correct, there can be large numbers of individuals.  There are currently several species of Crane Flies that are appearing in great numbers in Southern California, and we believe their numbers were affected by the record rains we had this past winter.  These Crane Flies pose no threat to your toddler and there is no need to relocate their rotting log.

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.

2 thoughts on “Crane Fly Life Cycle Explained: Discover Their Fascinating Journey”

  1. Hi there, i read your blog occasionally and i own a similar one and i was just curious if you get a lot of spam remarks?

    If so how do you prevent it, any plugin or anything you can recommend?
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    Reply
  2. Hi there, i read your blog occasionally and i own a similar one and i was just curious if you get a lot of spam remarks?

    If so how do you prevent it, any plugin or anything you can recommend?
    I get so much lately it’s driving me mad so any support is very much appreciated.

    Reply

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