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Crane Flies Explained: Not the Pests You Think They Are


The crane fly, often surrounded by misconceptions and myths, is not actually a mosquito predator as its nickname “mosquito hawk” suggests. More commonly known by its scientific name, this creature is a familiar sight worldwide.

Belonging to the large Tipulidae family, renowned for being one of the largest groups of flies, these insects are easily identified by their elongated legs and slender bodies, which can be mistaken for oversized mosquitoes. However, they do not bite or sting.

Currently, crane flies are quite prevalent in Middle Tennessee. Despite their intimidating mosquito-like appearance, they pose no threat. As adults, they are harmless, although they can become nuisances in large numbers.

These flies spend their larval stage burrowing underground until they mature and emerge for mating. While they rarely cause significant damage to lawns in small numbers, they are easy prey for birds and other predators that feed on insects.

Recently, we accidentally left the garage door open, and hundreds of crane flies swarmed in, attracted by the fluorescent lights of a plant setup.

Their presence can be particularly bothersome during lawn mowing when swarms of these large insects flutter around. Although they may look peculiar when attaching end-to-end during mating, they are not conjoined twin bugs.

Understanding crane flies sheds light on their ecological importance. Despite their ominous looks, these insects play a crucial role in the food chain.

They serve as prey for various birds, reptiles, and amphibians, and their larvae significantly contribute to decomposing organic material.

This article will explore the many ways crane flies benefit gardens and ecosystems, proving that their presence is more beneficial than it might seem.

Misconceptions and Nicknames

Crane flies are often mistaken for various other insects. Some people call them giant mosquitoes or mosquito hawks, while others mistakenly refer to them as “daddy long-legs,” a term better reserved for harvestmen arachnids.

Crane Flies Explained
Credit: Lagniappe

In places like summer camps, you’ll frequently hear shrieks of “Is that a mosquito? Kill it!” when these lanky bugs appear.

Despite their bad reputation, crane flies are completely harmless—they are not mosquitoes and will not bite or suck blood. Adult crane flies do not even eat; they might drink a bit of nectar, but their main focus is mating and laying eggs.

Females can lay up to 300 eggs in just a few days! You can distinguish male from female crane flies by the females’ larger abdomens, tipped with an ovipositor for laying eggs, which may look like a stinger.

Belonging to the Diptera order, crane flies are not typical indoor flies but are more commonly found on exterior walls or hovering near windows. Outdoors, they prefer damp environments rich in vegetation, often near water sources.

Their larvae, known as leatherjackets due to their tough skin, feed on decaying plant matter and can live in both wet and dry habitats.

Leatherjackets are legless in their youth, wriggling to move, and can extend tentacle-like protrusions if threatened—an odd but fascinating survival tactic.

They go through four growth stages before reaching adulthood, spending one to two weeks in the pupal stage near moisture. Afterward, adults have a short lifespan focused on flying, egg-laying, and possibly drinking nectar given their limited time.

Credit: thelawnman

Adult crane flies are known for their clumsy flying due to their elongated limbs, which are not aerodynamic and often detach easily—a possible escape mechanism from predators.

While leatherjackets can be nuisances to garden plants, crane flies contribute significantly to their ecosystems as food sources for many creatures and by helping break down leaf matter, inadvertently feeding smaller organisms.

Let’s clear up the misconception: crane flies are not mosquitoes. They are simply fulfilling their role, benefiting the environment more than harming it.

Although they might not need “Hi, My Name is Crane Fly” nametags, it is up to us to set the record straight and champion their true identity. Remember, their larvae might prepare tiny leafy salads for you—isn’t that adorable?

Physical Characteristics of Crane Flies

Often mistaken for their menacing counterparts—mosquitoes—crane flies are quite distinct. These gentle giants are affectionately dubbed “mosquito hawks,” despite not preying on mosquitoes.

Unlike their nickname suggests, adult crane flies do not eat at all. Their sole focus is mating and laying eggs during their short lifespan, which generally lasts just a few days to a week.

Crane flies can grow up to about 3 cm (1.2 inches) in length and feature a long, slender abdomen with disproportionately long, thin legs that can make them look awkward in flight.

Their wings are narrow, and their long antennae consist of multiple segments. You might spot them in shades of brown, green, or white.

These creatures are sometimes called “daddy long-legs,” though this name more typically refers to the daddy long-legs spider or cellar spider, scientifically known as Pholcus phalangioides.

As adults, crane flies are harmless; they are poor fliers and lack the ability to bite, sting, or suck blood. In fact, their mouthparts are not designed for eating—they can only sip water, contributing to their fleeting lifespan.

Belonging to the Diptera order, a term originating from the Greek words for ‘two’ (di) and ‘wings’ (ptera), crane flies are true flies with just one pair of wings. The second pair has evolved into club-shaped structures called halteres, which act like gyroscopes to stabilize flight.

Despite the common myth, crane flies are not mosquito hunters and provide no pest control benefits.

This misconception likely stems from their nickname and size, leading some to believe they feed on mosquitoes. In reality, they pose no threat to humans and are more of a nuisance than anything else.

The larvae of crane flies, known as leatherjackets, feed on plant roots and can damage lawns and gardens. However, they also play a crucial role in the ecosystem by decomposing organic matter.

Understanding the lifecycle of a crane fly offers insight into these misunderstood creatures. Their lifecycle includes four stages: egg, larva, pupa, and adult. Eggs are laid in moist soil and hatch into larvae that feed on organic materials and plant roots.

After a few weeks or months, depending on environmental conditions, they transition into the pupal stage—a dormant period of metamorphosis lasting about two weeks. Once adults emerge, their brief existence focuses on reproduction.

In appearance, crane flies resemble giant mosquitoes but are quite different. They measure about 2.5-5 cm (1-2 inches) in length, with a frail body and long legs that are often twice their body length.


Their wings are clear and wider than their body, and they sport short, feathery antennae unlike the long proboscis of mosquitoes. Crane flies range in color from pale gray to light brown and lack the specialized mouthparts mosquitoes use for blood feeding.

Only female mosquitoes need blood for egg production, while male mosquitoes and crane flies do not engage in blood feeding.

Apart from “mosquito hawk,” crane flies have several other nicknames like “golly whoppers,” “gallinippers,” and “skeeter eaters,” reflecting their misunderstood nature.

Though sometimes mistakenly called spiders due to their long legs, crane flies are far from it, existing peacefully within our ecosystems.

Check The Ultimate Guide to Ladybugs in the Garden: Beneficial Beetles Explained

Diet and Behavior of Crane Flies

What Do Crane Flies Eat?

Despite their nickname “mosquito hawks,” crane flies do not actually feed on mosquitoes. Instead, they have a very brief lifespan focused primarily on reproduction. Adult crane flies typically do not eat anything during their short lives, which are primarily dedicated to mating.

The immature stage of these insects, known as crane fly larvae, have hearty appetites. They consume various organic materials, including decaying vegetation, roots, and occasionally algae if they are in an aquatic habitat.

Known as leatherjackets in their larval stage, these creatures can become a nuisance in gardens and lawns, damaging plants by feeding on their roots.

The misconception that these insects are mosquito hunters likely stems from their misleading nickname. Although they pose no danger to humans or pets, the larvae can cause havoc in outdoor spaces.

Diet and Behavior of Crane Flies
Credit: Burns Pest Elimination

Behavior of Crane Flies

Crane flies have a fleeting lifespan, generally lasting only about one or two weeks, with their main goal being reproduction. Adult crane flies are harmless to people, as they do not bite or sting.

The larvae, or leatherjackets, are the real troublemakers, especially for your green spaces, as they feed on the roots of young plants.

Most active in the evenings and at night, adult crane flies are attracted to light and can often be seen flying around in a somewhat haphazard and amusing way due to their long, spindly legs and wings.

Habitat of Crane Flies

Crane flies thrive in damp environments such as woodlands, streams, and even urban settings, where their larvae require moisture to survive.

These larvae are primarily found in moist soil or under decomposing leaves in humid areas and play a crucial role in breaking down organic material, aiding the nutrient cycle in these ecosystems.

Adult crane flies, on the other hand, are commonly spotted in meadows and gardens, attracted by lights at night.

Are Crane Flies Poisonous or Dangerous?

Crane flies, also known as mosquito hawks, may appear intimidating due to their large size and long wings, but they are neither poisonous nor harmful to humans. Adult crane flies mainly focus on mating and laying eggs and do not have the means to bite or sting.

While they can be a nuisance if they invade your home in large numbers, they do not pose any health risks.

What Does the Crane Fly Larva (Often Called a Giant Mosquito) Look Like?

The larval stage of what is often incorrectly called a “giant mosquito” is fascinating. These larvae are cylindrical with tough, leathery skin colored grey to brown.

They lack legs but have a distinctive, fleshy rear lobe used for moving around. Their small heads retract into their bodies, making them hard to spot.

These larvae typically reside in moist soil or amongst decaying matter and play a significant role as decomposers in their ecosystems.

Crane Fly Larva
Credit: Missouri Department of Conservation

What Do Crane Fly Larvae Eat?

Crane fly larvae are equipped with chewing mouthparts, making them effective decomposers of decaying plant material, thus enriching the soil. While beneficial in this role, some species can damage crops and lawns by feeding on the roots of young plants.

Commonly known as leatherjackets, these larvae are greyish-brown and can be up to 40mm long. They live underground and are formidable feeders on the roots of lawns and seedlings.

While chemical treatments for leatherjackets are limited, biological control through the application of parasitic nematodes like Steinernema feltiae provides a safe and effective solution.

These nematodes infect the larvae, introducing lethal bacteria that effectively manage the leatherjacket population.

In summary, most crane fly larvae are harmless and play a crucial role in their habitats by breaking down organic matter and returning nutrients to the soil.

Crane Flies Around Your Home

Have you ever wondered about those large, mosquito-like insects buzzing around your home? They may look intimidating due to their size, but unlike mosquitoes, they don’t bite.

These insects often spark curiosity, especially during the spring and early summer months when they are most prevalent. Known as crane flies, they are sometimes mistakenly called “mosquito hawks,” although this nickname usually refers to dragonflies.

Crane flies belong to the Diptera order, a term derived from the Greek words “di” (two) and “ptera” (wings), highlighting that, like all true flies, they have just one pair of wings. These creatures are quite delicate, sporting long legs and a tan hue.

An adult crane fly’s body is about half an inch long, with a slender abdomen and legs that can stretch over an inch and a half.

Behind each wing, crane flies feature a unique structure known as a haltere, which resembles a tiny golf club and helps stabilize their flight by vibrating rapidly, much like a gyroscope stabilizes an airplane.

These structures are visible to the naked eye and are more prominent in crane flies than in other Diptera species like houseflies or hover flies.

In Texas, where they are particularly common, crane fly larvae thrive in moist environments such as decaying leaves or compost piles.

These larvae have a cylindrical, grey-brown body, sometimes with fleshy lobes at the rear, and they primarily feed on decomposing organic matter.

Unlike their adult counterparts, who live only a few days and typically don’t eat, the larvae play a crucial role in breaking down dead plant material.

Although harmless, crane flies can cause a disturbance in homes, as they are attracted by indoor lighting. They clumsily flutter against lampshades and walls, yet they pose no medical threat as they don’t bite, sting, or carry diseases.

During late winter to early spring, adult crane flies often rest on external walls or plants and are drawn to lights, sometimes entering homes through open doors or windows.

To manage crane flies, ensure that windows and doors have intact screens. Using yellow “bug lights” can also deter these insects since they are less attracted to such lighting.

While these steps won’t completely stop crane flies from entering your home, they will significantly reduce their numbers.

The Role of Crane Flies in Your Garden

You might think that, like mosquitoes, crane flies are unwelcome visitors in your garden. However, the situation is not that straightforward.

Crane flies, often referred to as mosquito hawks and occasionally confused with dragonflies, are commonly mistaken for their blood-sucking relatives. However, they are actually harmless to both humans and pets.

Crane flies, with their long, spindly legs and significant size, may resemble giant mosquitoes, but they prefer hanging out in moist areas, sipping nectar and other plant juices.

Dragonflies, on the other hand, are nimble predators sporting large, transparent wings and streamlined bodies. One of the coolest things about dragonflies is their diet, which includes a variety of pesky insects such as mosquitoes, flies, and gnats—making them a triple threat!

  • Crane Flies in Your Garden

There is a myth that crane flies, often called mosquito hawks, damage plants or gardens. In reality, crane flies are beneficial, helping with plant pollination, soil aeration, and acting as food for other garden-friendly wildlife.

Yet, their larvae, known as leatherjackets, are also known to feed on plant roots. Let’s explore the benefits and drawbacks of hosting these creatures in your garden.

  • Benefits of Crane Flies

Leatherjackets contribute to a balanced ecosystem by preying on small insects and other tiny creatures.

They also break down decaying organic materials in the soil, enriching it and recycling nutrients. Moreover, like their infamous cousins, the mosquitoes, crane flies are pollinators and serve as a vital food source for birds, frogs, and various insects.

  • Potential Drawbacks

Despite their benefits, crane fly larvae can sometimes feed on plant roots. Typically, their presence indicates a thriving soil ecosystem, but severe infestations might harm plant roots.

To keep your garden thriving, focus on maintaining its health through adequate watering and nutrient-rich soil. However, if you spot signs like wilted or yellowing leaves, especially near water features, it could suggest a significant infestation of crane fly larvae.

To keep crane flies at bay, remember that the plants that deter regular mosquitoes usually aren’t favored by crane flies either.

So, while crane flies might look daunting, they mostly bring more benefits than harm to your garden!

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