Mayflies and mosquitoes are two distinct types of insects that are often found near bodies of water, but they differ in many ways. While mayflies are known for their unique life cycle and short adult lifespan, mosquitoes are infamous for their blood-sucking habits and potential to spread diseases.
Mayfly larvae, also called nymphs or naiads, have a slender and soft-bodied appearance, with leaf-like or feathery gills along their sides or on the top rear portion of their abdomen 1. On the other hand, mosquitoes are flying insects that thrive in various parts of the world and are present in over 3,500 different types 2. Their bites are known to cause itching and swelling, while some mosquitoes are vectors of serious illnesses.
Both insects play their part in the ecosystem, with mayflies contributing through their unique life cycle 3, and mosquitoes acting as indicators of environmental changes and health risks. As we explore the fascinating world of mayflies and mosquitoes, we’ll discover their distinct characteristics and better understand their roles in our environment.
Mayfly Vs Mosquito: Basic Differences
Slender and soft-bodied
Unwinged in larval stage, sport wings as adults
Leaf-like or feathery gills on abdomen
Smaller eyes in larval stage, larger in adults
Small-sized with a slender body
Long legs and a proboscis for feeding
Wings present in adult stage
Egg, larva/nymph/naiad, subimago, adult
Larval stage spent in water for months or years
Larvae have external gills
Adult stage very short-lived (hours to days)
Egg, larva, pupa, adult
Larval and pupal stages spent in water
Adult stage lives a few weeks
Adult female feeds on blood to produce eggs
Found in clean, oxygen-rich aquatic environments
Larvae often live on rocks in fast-flowing water
Larval and pupal stages thrive in standing water
Adults found near water sources and in various climates
Larvae feed on algae, detritus, and other small organisms
Adults do not eat
Larvae consume microorganisms and organic matter
Adults feed on nectar, while females require blood meals for egg production
Impact on Humans
Bites and Itchiness
Mayflies do not bite or cause itchiness.
They are harmless to humans.
Mosquitoes bite, causing itchiness and discomfort.
Female mosquitoes feed on human blood for nutrients needed to produce eggs.
Diseases and Health Risks
Do not transmit diseases to humans.
Minimal health risk, mostly associated with their swarming behavior which can cause nuisance.
Transmit deadly diseases, such as malaria, dengue fever, and Zika virus.
Major health risk globally, especially in tropical and subtropical regions.
High (transmits diseases)|
Both mayflies and mosquitoes have an impact on humans, although significantly different. While mayflies are harmless, mosquitoes can cause serious health issues through their bites. It is essential to take preventive measures against mosquito bites to protect oneself from the diseases they carry.
Role in Ecosystems
Mayflies primarily inhabit rivers and streams as larvae, consuming algae and smaller organisms. Their presence is an indicator of good water quality. Mosquitoes, on the other hand, lay their eggs in standing water and can survive in a wider range of environmental conditions, playing a role in the spread of diseases like malaria.
Comparison Table: Mayflies vs Mosquitoes
Standing water, various environments|
Algae, smaller organisms (larvae stage)|
Female mosquitoes feed on blood, males feed on nectar|
Good water quality indicator|
Pollinators (some species)|
Disease vectors (such as malaria, dengue, and Zika virus)|
Mayflies and mosquitoes share a wide range of predators. Examples include:
Fish: Many species feed on mayfly larvae and adult mosquitoes.
Birds: Swallows and other insectivorous birds consume both mayflies and mosquitoes.
Other insects: Dragonflies and damselflies are known to prey on mosquitoes and mayfly larvae.
In summary, mayflies and mosquitoes have unique roles in their respective ecosystems. Mayflies are indicators of healthy aquatic environments, while mosquitoes can be both pollinators and disease vectors. Both mayflies and mosquitoes serve as important food sources for a variety of predators, maintaining the balance of ecosystems.
Insects That Resemble Mosquitoes
In this section, we will take a closer look at three insects that resemble mosquitoes. These insects are often mistaken for mosquitoes due to their physical appearance. However, they have different characteristics and their presence in the environment can sometimes be beneficial.
Commonly mistaken for giant mosquitoes
Much larger than mosquitoes, size ranging from 2-60mm
Possess long, slender legs with wings spanning approximately 20mm
Do not bite or transmit diseases
Larvae feed on decaying plant material, adult crane flies feed on nectar or not at all
Crane flies are a prime example of an insect often confused with mosquitoes. Despite their large size and long legs, crane flies are harmless and do not bite. They can be beneficial to the ecosystem, as their larvae help break down decaying plant material, which enriches the soil.
Small, delicate insects resembling mosquitoes
Similar in size, about 1-4mm
Do not bite or transmit diseases (non-biting midges)
Larvae can be aquatic or terrestrial, feeding on algae or decaying organic matter
Adult midges can form swarming patterns, mostly seen during dusk or dawn
Midges, another insect commonly mistaken for mosquitoes, have similar size and appearance but do not bite or transmit diseases. Their presence can be annoying, especially in swarming patterns, but they are generally harmless.
Resemble mosquitoes with delicate bodies and clear wings
Size range between 2-5mm
Do not bite or transmit diseases
Larvae feed on the fungi that grow in damp, organic matter (potting soil, for example)
Attracted to damp, overwatered plants
Fungus gnats are yet another insect that resembles mosquitoes. They have delicate bodies and clear wings but do not bite or transmit diseases. Fungus gnat larvae feed on fungi growing in damp, organic matter, so they are primarily attracted to over-watered plants.
Decaying plant material, soil|
Decompose plant material|
Aquatic or terrestrial, algae or decaying|
Damp, organic matter (potting soil)|
Decompose fungi in soil|
*Note: This refers to non-biting midges, some midge species do bite.
Mosquito and Mayfly Management
Protecting Yourself and Your Yard
To protect yourself and your yard from mosquitoes and mayflies, follow these simple steps:
Remove standing water: Eliminate any sources of stagnant water around your yard, as it’s a breeding ground for mosquitoes.
Trim vegetation: Keep your yard well-trimmed, as both insects tend to congregate near tall grass and overgrown shrubs.
Install screens: Place window screens and screen-enclosed porches on your property to keep pests out.
Mosquito control example:
Pros: Reduces mosquito populations; prevents the spread of diseases like West Nile virus and dengue fever.
Cons: May require using chemicals which might have a negative environmental impact.
Mayfly control example:
Pros: Mayflies are generally harmless and have a short life span; natural predator of other insect pests.
Cons: Large swarms can be a nuisance; may cause respiratory problems for people with allergies.
Up to several weeks|
Usually 1-2 days|
Blood (females) & nectar|
Algae & other small insects|
Can transmit to humans|
Requires more effort|
Requires less effort|
Taking these steps to protect yourself and to control pests can help your yard be a more enjoyable space during mosquito and mayfly season.
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 – Mayfly
Bizzare unknown fly with huge eyes
Location: Fairfield, Maine USA
August 13, 2010 2:51 pm
I found this fly on my Cruiser and another under an apple tree leaf. The one on the car seemed very aware of my presence and at one point seemed to be doing some kind of ”defending it’s territory dance” at me! It was about a half inch long (just the body.) It had very bright green large eyes and two very long appendages coming out of its tail end. Is this a stage of life for a dragonfly, or just an adult of something entirely different? It looks like it could be related…can you identify this please?
These are beautiful images of a Mayfly, even though it is August. Though Mayflies are most common in the spring, especially May, they may also be found at other times of the year. Whenever they are found, there is one thing that is constant. They do not live long as winged adults, many dying the first day. The name for the order, Ephemeroptera, is explained on BugGuide as: “from the Greek ‘ephemeros’ (of or for a day; short-lived) + ‘pteron’ (wing; feather) refering to the short time that adults are on the wing.” Mayflies are unique in the insect world in that they molt twice once they are winged and capable of flight. The aquatic nymphs metamorphose into subadults or subimages which are called duns by anglers. They molt a second time into true adults or images which are called spinners by anglers. According to BugGuide: “Adult (imago): body delicate or “flimsy”, varying from almost transparent to white, yellow, orange, green, brown, or black; thorax and abdomen bare, often shiny; legs slender, solid color; front legs often held forward and sometimes upward in front of head when at rest; forewings large, triangular, with many cross veins; hindwings much smaller than forewings (hindwings absent in some species); both wings usually transparent but sometimes patterned, held vertically and together above thorax when at rest Pre-adult (subimago): wings cloudy in appearance, body dull and pubescent, with appendages somewhat shorter — but otherwise similar to imago; pre-adults molt a final time to become adults Nymph: body elongate, flattened or cylindrical, usually greenish or brownish but color varies according to the type of food eaten; legs long; antennae short; abdomen with lateral plate-like gills and usually three long thin tail projections (cerci); some species have only two cerci.” We believe your specimen is a Common Burrower Mayfly in the family Ephemeridae, based on images posted to BugGuide.
Thanks so much for the i.d. and detailed information!
Interesting how the body color is affected by diet.
Letter 2 – Mayfly
Can you identify?
This bug landed on the outside of my office window a while back and I’ve saved the picture ever since hoping to find out what it was. I’ve never seen a bug quite like this. Any ideas?
Even though this is a Mayfly, they appear in other months as well.
Letter 3 – Mayfly
Tue, Mar 17, 2009 at 4:38 AM
A friend of mine who lives in Temecula, CA, is wondering what sort of bug landed near his computer, one early morning in June of 08.
I have been searching the internet trying to figure out what it might be, but am alas, at a loss. However, I am no insect expert at all, so it may be something simple….. Can you shed some light on this?
Anyone who uses the word alas in a letter is a peach for us. Despite its appearance in June, this is a Mayfly, an insect in the order Ephemeroptera. We are not very good at identifying the specific species of Mayflies, so we hope this general identification will suffice. This may be a Small Minnow Mayfly in the genus Callibaetis as evidenced by images on BugGuide. Mayflies often appear in great numbers near bodies of water when the aquatic nymphs mature into adults and swarm in their annual nuptial flight.
Letter 4 – Mayfly
Big eyed bug in PA
Tue, May 26, 2009 at 8:50 AM
What’s this bug? Thanks!
Northern PA, US
This is a Mayfly in the order Ephemeroptera. We haven’t the skill to take the taxonomy beyond the level of order. We absolutely love the perspective on your photograph.
Letter 5 – Mayfly
Subject: Is that a stinger?
Location: St. John’s Newfoundland
July 20, 2016 6:16 pm
Hi there,, saw this little creature tonight. I’ve lived in this area all my life and I don’t recall ever seeing one before. Any idea what this little (about 1.5 inches) guy might be? And is that a stinger on his back end? Thank you!
Signature: Curious on the Rock
Thank you for submitting your identification request.
Please understand that we have a very small staff that does this as a labor of love. We cannot answer all submissions (not by a long shot). But we’ll do the best we can!
Thank you for your quick response! I’ve done a little research and it looks like my friend is a Mayfly!
We know you already identified your Mayfly, but it is such a nice image that we want to post it so our readers will learn to recognize Mayflies. We believe your individual is a Giant Mayfly in the genus Hexagenia which we researched on BugGuide. We also want to address your stinger question. According to BugGuide, Mayflies have: “usually three long thin tail projections (cerci); some species have only two cerci” but there is no further explanation. The features of Mayflies are described on Mayfly.org including “It also features three long cerci or tails at the end if the body.” Once again, the purpose or function of the cerci are not explained. We will continue to research this matter.
Letter 6 – Mayfly
Subject: I found a weird googly eyed bug
Location: Tangent, Oregon, United states
August 7, 2016 3:34 pm
I was at a park and found this strange bug with 4 legs and big white googly eyes I can’t find any info anywhere can you help me identify it please? it was awfully cute!
This is a Mayfly in the order Ephemeroptera.
Letter 7 – Mayfly
Subject: Friendly winged insect
Location: South Pasadena, CA
August 12, 2017 7:19 pm
Hello Mr. Bugman,
This bug alighted on my plate this evening at dinner on the patio. Curious to know what it is.
This is a Mayfly, and we are confident it is in the genus Callibaetis which we discovered on Wayne’s Word and we verified on BugGuide that it might be Callibaetis pallidus. Another species in the genus pictured on BugGuide that looks quite similar is Callibaetis californicus. Mayfly nymphs are aquatic, so there must be some nearby body of water that will allow the nymphs to develop. Winged adults are feeble fliers that cannot travel great distances.
Letter 8 – Mayfly
Subject: Mosquito / may fly / dragon fly with tail
Geographic location of the bug: Long Island, NY
Time: 01:43 AM EDT
Your letter to the bugman: These long tailed flies are swarming our house. They don’t move much. They just sit on the screens and doors -Many until they die. We’re presuming they hatched from dirty rain gutters from a house we just bought. Some seem to be coming from vents outside that lead to the attic. Please don’t let them be in the attic… They have long curved bodies and long tails. We have a newborn and are nervous about them getting in because there are thousands of them. It’s like a scary movie bug swarm. Hoping they hate human blood. Are they a beneficial fly that will prey on a nuisance species or are they out to get us? Thank you.
How you want your letter signed: Concerned new parents.
Dear Concerned new parents,
Other than being a nuisance when they are numerous, Mayflies like the one in the image you submitted are perfectly harmless and they will not harm you or your home. The larvae of Mayflies are aquatic, so we suspect you are near some body of water.
I’m about half a mile from a river. But there was a lot of standing water all over this property before we took ownership of it.
Letter 9 – Mayfly
Subject: Please Identify
Geographic location of the bug: Lake Chelan, WA
Time: 12:26 PM EDT
Your letter to the bugman: Approximately 2″ from antennae to end of “stinger.” Yellow. Still for hours. On shady side of pole. Both big and little lacey wings.
How you want your letter signed: Thanks, Beatrice
This is a Mayfly in the insect order Ephemeroptera, a group that does not feed as adults. They are short lived and because they often appear in great numbers, they are an important food source for fish, birds and other insects.