Do Crane Flies Eat Mosquitoes? Debunking Myths & Facts

Crane flies are often mistaken for giant mosquitoes due to their similar appearance. However, these large, gangly insects play a different role in the ecosystem. Despite being commonly referred to as “mosquito hawks” or “skeeter eaters,” adult crane flies do not actually consume mosquitoes source.

Their larvae, known for causing damage to lawns, also have a different diet. Preventing this damage can be achieved through simple maintenance and irrigation practices source. So, although they may look menacing, crane flies pose no threat to mosquitoes and have a unique place in the ecosystem.

Crane Flies and Mosquitoes

Misconceptions about Mosquito Eaters

Crane flies are often mistaken for mosquitoes due to their long legs and elongated, slim bodies1. They are known by various nicknames, such as “mosquito hawks,” “skeeter eaters,” and “daddy long legs.” Despite these nicknames, crane flies do not consume mosquitoes2.

Although they may appear similar to mosquitoes, crane flies are mostly harmless to humans. They do not bite, sting, or transmit diseases3. Adult crane flies live for a short period of time, usually about two weeks4.

There is a widespread belief that crane flies are predators of mosquitoes. This is not true. In fact, they serve as a food source for insectivores like frogs, swallows, and armadillos5. They play an important role in maintaining a healthy ecosystem.

Crane Flies vs. Mosquitoes: A Comparison

Feature Crane Flies Mosquitoes
Size 0.5-1.25 inches1 Smaller
Diet Not predatory5 Blood feeders6
Harmful to humans No3 Yes6
Lifespan Up to 2 weeks4 Variable7

Key characteristics of crane flies:

  • Long legs and slim bodies
  • Do not consume mosquitoes
  • Harmless to humans
  • Short lifespan

In conclusion, crane flies are not predators of mosquitoes. They do not eat mosquitoes, and both insects have different feeding habits and overall characteristics. It is essential to differentiate between the two organisms to understand their roles and functions in the ecosystem.

Life Cycle of Crane Flies

Eggs and Larval Stage

Crane flies start their life cycle as eggs, which later hatch into larvae. The larvae, also known as leatherjackets, are small and brown with a segmented body. They can be tan, gray, or greenish, with a definite head and tiny, fleshy projections at the hind end. Despite not having legs, crane fly larvae are able to move and feed.

Crane fly larvae primarily inhabit moist soil, where they feed on decaying organic matter and plant roots. Some species might have multiple generations per year, such as the marsh crane fly, while others, like the common European crane fly, only have one generation annually.

Pupae and Adulthood

When fully grown, the larvae metamorphose into pupae which are gray to brown in color and about 1 inch long. Pupae do not feed and eventually transform into adult crane flies.

Adult crane flies have long legs and elongated, slim bodies that are often mistaken for mosquitoes. They typically range in size from 0.5 inches to 1 inch, depending on the species. Adults have very short lives, usually lasting just one to two weeks. Contrary to popular belief, adult crane flies do not feed on mosquitoes; instead, they consume nectar or may not feed at all in their brief adulthood.

In summary:

  • Larvae:
    • Small and brown with segmented bodies
    • Feed on decaying organic matter and plant roots
    • Inhabit moist soil
  • Pupae:
    • Gray to brown color
    • Non-feeding stage
  • Adults:
    • Long legs and slim bodies
    • Life span of one to two weeks
    • Do not feed on mosquitoes

Crane Flies’ Diet and Feeding Habits

Adult Crane Flies

Adult crane flies belong to the family Tipulidae and are members of the order Diptera. They have a slender, mosquito-like body with long legs. Interestingly, adult crane flies do not feed on mosquitoes nor do they have a substantial diet. Their primary purpose is to mate and lay eggs.

Larval Stage of Crane Flies

The diet and feeding habits of crane fly larvae are significantly different from the adults. Larvae, also known as leatherjackets, mainly feed on:

  • Grass: They consume plant material in various stages of decomposition.
  • Roots: Crane fly larvae feed on the roots of grasses and other plants, which can cause damage to turf and lawns.
  • Soil debris: Organic matter found in soil is an important food source for the larvae.
  • Algae: They might feed upon algae in moist environments.

Different species of crane flies might have varying preferences for food sources during their larval stage. The impact of their feeding can be significant, particularly on lawns and grassy areas, as they consume the plant roots and other organic materials close to the soil surface.

In summary, adult crane flies do not have a significant diet, while their larvae feed on various plant materials found in the soil, such as grass, roots, and algae. The feeding habits of crane fly larvae can sometimes cause damage to lawns and other grassy environments.

Crane Flies’ Role in the Ecosystem

Predators and Prey

Crane flies play an important role in the ecosystem as a food source for various insectivores. Some of their predators include:

  • Frogs
  • Swallows
  • Armadillos
  • Spiders
  • Fish
  • Birds

Contrary to popular belief, crane flies are not significant predators of mosquitoes, and they are not called “skeeter eaters.” Instead, they are mostly harmless creatures that do not bite humans or pets 1.

Impact on Vegetation and Lawns

Crane flies can have both positive and negative impacts on vegetation and lawns. As larvae, also known as leatherjackets, they sometimes feed on roots and stems of plants, causing minor damage to gardens, meadows, and pastures2. However, they are also a valuable part of the ecosystem, contributing to nutrient cycling and providing a food source for other organisms.

Impact on Vegetation Pros Cons
Crane flies Contribute to nutrient cycling Can cause minor damage to plants

In conclusion, it’s essential to recognize the role that crane flies play in maintaining a healthy ecosystem. While they may not be the mosquito-eating heroes that some people believe them to be, they serve as a crucial food source for various insectivores and contribute positively to the natural environment.

Controlling Crane Fly Populations

Natural Methods

  • Introduce nematodes: These microscopic worms can target and kill crane fly larvae. Apply them to the soil where crane fly populations are high.

  • Predatory insects: Encourage hoverflies, beetles, and other insects that prey on crane fly larvae by planting flowers and shrubs that attract them.

  • Eliminate standing water: Crane flies are attracted to moist environments, so removing sources of standing water like tires, toys, and puddles can help reduce their presence.

  • Use window screens: Installing window screens on windows and doors can prevent adult crane flies from entering your home or other structures.

Method Pros Cons
Nematodes Highly effective; environmentally friendly May require reapplication
Predatory Insects Chemical-free; promotes healthy ecosystem May not control large populations
Standing Water Removal Disrupts breeding habitats; reduces mosquito populations too Requires diligence; labor-intensive
Window Screens Physical barrier against adult crane flies Installation and maintenance

Chemical Treatments

  • Insecticides: Apply chemical treatments targeting crane fly larvae to your lawn or garden. Follow the manufacturer’s instructions for proper use and application rates.

  • Consider environmental factors: Crane fly populations can vary yearly due to differences in weather patterns. It’s important to take environmental factors into account before deciding on chemical treatments to avoid excessive use or overreliance on chemicals.

When selecting a chemical treatment, consider its impact on non-target species and the environment. Some chemicals may pose a danger to beneficial insects or organisms, so it’s essential to follow the recommended safe application guidelines. Remember to weigh the pros and cons of chemical treatments before using them to control crane fly populations.

Treatment Pros Cons
Chemical Insecticides Often effective at reducing crane fly populations May be harmful to beneficial insects; environmental impact
Environmental Factors Aids in proper treatment selection and timing Unpredictable; requires monitoring

Footnotes

  1. Crane flies – Agricultural Biology 2 3

  2. Managing Crane Fly in Lawns | OSU Extension Service 2

  3. What are Crane Flies? – AgriLife Today 2

  4. What’s Up With All the Crane Flies? | University of Arizona News 2

  5. What are crane flies? – AgriLife Today 2

  6. Mosquitoes | National Geographic 2

  7. Mosquito Life Cycle | American Mosquito Control Association

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 – Pedicia albivitta Crane Fly and Fishing Spider Exoskeleton

 

Spiders, Crane Flies
Folks,
You have a great site — thanks very much. I was preparing some nature pics of my own and used your resources to identify a few things. I’ve included some links below to a few of my pictures. A couple of questions: 1) In "crane_fly2.jpg", the bug has some red blobby things on its back. Any idea what that is? Eggs? 2) I believe that the spider skin is a skin from the spider in Fishing spider, I presume. I found a couple of these skins in the wood pile where the spider lives. It looks hollow to me and appears to have split apart when the spider was shedding it. Does this make sense or is it a dead spider?
Take care,
Andre Paquette
Ottawa Ontario Canada

Hi Andre,
The Crane Fly photo you inquired about is difficult to see, but the red blobs are probably mites which often infest Crane Flies. The skin is indeed a Dolomedes Fishing Spider exoskeleton. We really wanted to identify your beautiful black and white Crane Fly and we found Pedicia albivitta on the Crane Flies of Pennsylvania website.

Letter 2 – Mosquito Hawks

 

Lately I have been seeing some of the large mosquito-like creatures and am wondering: Do they really eat mosquitos? I’m talking about the ones that look just like mosquitos but are much lagers and fly with their legs dangling in an almost comical way. They never bother us excpt for an occasional tickle as they brush over an arm, and we are careful to not kill them, ushering them outside if the cat hasn’t already gotten them… Thanks. I just occasioned upon your web page thanks to google…
LOU

Dear Lou,
I’m so happy that search engine is doing what it is supposed to do, direct the curious to our site. You are talking about crane flies which though they are known locally in some areas as mosquito hawks, do not really feed on mosquitos. They have soft mouthparts incapable of biting. The Giant Crane Fly, Holorusia hespera, is one of the world’s largest flies with a 3 inch wing span. I’m also happy to hear we have a reader who knows how to cope with insect visitors in a kind and logical manner instead of just bombarding the entire environment with pesticides to no avail.

Thanks! I found a corroborative answer in further searching, Crane Flies! Never heard the name but known the interesting creatures all my life. And Mosquito Hawks are also names for dragonflies and Damsel flies. Fascinating photo article on Damsel flies in National Geographic recently, too.
Thanks, Bugman!
Lou

Letter 3 – #9999: Giant Eastern Crane Fly

 

Damsel fly?
May 13, 2010
Here again is another bug we had the pleasure of seeing in the Porcupine Mountains in August. This one, I also searched in the Kaufman’s field guide to North American insects but was unable to find. If you could help with this as well, my family and I would greatly appreciate it.
Amy Padgett
Porcupine Mountains, Michigan

Giant Eastern Crane Fly

Dear Amy,
You have the distinction of being our 10,000th posting.  This lovely and gangling creature is a Giant Eastern Crane Fly, Pecidia albivitta.  We identified it on the Crane Flies of Pennsylvania website pretty far down the Limoniinae page where this information is provided:  “This is one of the most conspicuous and beautiful crane flies in Pennsylvania.  It is common and widely distributed throughout the northeastern United States and Canada.  The adults are on the wing in June and again in September.  Crane flies of this group can be distinguished from all other adult crane flies by the dark brown triangle on the wings.  A dark costal margin, a broad seam along vien Cu, and a similar dark seam along the unusually oblique cord form this triangle.  The females reach the large size of 35 mm, while the males are slightly smaller.  Abdomen is whitish gray in color, the tergites with triangular or diamond-shaped darker gray patches that are bordered by rusty yellow.  The adults can be found in moist woods, boggy areas, cold springs, saturated springy hillsides, along streams and shaded tributaries where the aquatic carnivorous larvae develop.  Larvae of this species have creeping-welts on abdominal segments 4-7 and live in the edge of cold streams.
”  BugGuide has many submissions of this species.

Ed. Note: We actually miscounted.  This is really our 9999th post.

Letter 4 – Nectaring Limoniid Crane Fly

 

Subject: Nectaring Fly?
Location: Sussex County, NJ
August 5, 2017 5:50 am
Hi again,
Found this on my rudbeckia yesterday. It appears to be some sort of fly, but I’m having a hard time figuring out what Family? It has the general look of a crane fly, but is much smaller than any crane flies I’ve seen, only maybe 1/3 inch. Also, I’ve never seen a proboscis on a crane fly. Am attaching dorsal and ventral views and hope you can shed some light on the identity.
One other note, I was able to gently nudge it with my finger without it making any effort to get away from me – very intent on the flower. When it finally moved, it simply flew about a foot to another flower.
Signature: Deborah Bifulco

Limoniid Crane Fly

Dear Deborah,
Thanks for resending the images.  We believe we have identified your Crane Fly as a member of the family Limoniidae, the Limoniid Crane Flies.  Our first clue was this image on BugGuide of a Crane Fly in the genus
Limonia, though unlike your individual, the wings are spotted.  BugGuide does say this of the subgenus Geranomyia:  “One of three groups of crane flies, all in Limoniidae, that have long mouthparts for feeding on flowers. Often found bobbing up and down while perched.”  This BugGuide image of Toxorhina magna looks like an exact match to us, and both this individual and your individual have ovipositors, indicating they are female.

Limoniid Crane Fly

Thanks so much, Daniel!  And glad to know that I was on the right track with crane fly.  I’m accustomed to seeing crane flies that are much larger than this, which is what was throwing me.  And thanks for pointing out the ovipositor – I can see it clearly now that I know what I’m looking for.
Deborah

Limoniid Crane Fly

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 “Do Crane Flies Eat Mosquitoes? Debunking Myths & Facts”

  1. Thank you for having a page for info on such things as insects and bugs. These are things that my children and I talk about and often come up with questions about. I will be returning to your page when we wonder about bugs again. And it looks like you have some animal information on here too. Thanks again.

    Reply
  2. so are you saying that there’s nothing to do about these crimes lies and just live with them their bombard in my entire garage and anytime I open the door they fly in

    Reply
  3. Thanx for the info!! I’ve been wondering if they were what many people claimed……”the eater of mosquitos'” It seems I had read an article looong time ago that they were actually male mosquitos!!

    Reply

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