Flies are fascinating creatures that can be found in a variety of environments across the globe. One might be surprised to learn that there are over 100,000 different kinds of flies identified by scientists worldwide, including common ones like house flies, horse flies, gnats, midges, and mosquitoes1. All these flies belong to the insect order Diptera, characterized by their two wings, unlike most other insects that possess four wings.
Each type of fly has unique features and habits. Adult flies, for instance, have diverse feeding habits — some have thin sucking mouthparts to feed on liquids like mosquitoes, while others have sponging mouthparts, as seen in house flies2. Their diverse lifestyles and environments also lead to varying control methods, with the most effective way to manage filth flies being keeping your home and yard clean3.
Fly varieties such as small fruit flies (also known as vinegar flies) specifically thrive in overripe fruits4. As a result, proper fruit and garbage storage is essential for reducing their presence. Learning about different types of flies can help us better understand their impact on our surroundings and implement appropriate measures to manage them effectively.
Different Types of Flies
- Also known as Musca domestica
- Typically less than 3/8 inch in length
House flies are common, cosmopolitan companions of humans and domestic animals. They are more prevalent during the hotter summer months.
- Scientific name: Drosophila
- Attracted to overripe and fermenting fruit
Fruit flies are tiny insects that feed on the sugars found in ripe and rotting fruit. They are commonly found around fruit bowls and trash cans in homes.
- Known for their painful bites
- Lay eggs near water bodies
Horse flies are larger than house flies and are attracted to livestock and humans. They are known for their painful bites, which can occasionally transmit diseases.
- Non-biting relatives of mosquitoes
- Common near water
Midges are small, delicate-looking flies that resemble mosquitoes. However, they do not bite or transmit diseases like mosquitoes do.
- Often infest homes in late summer and fall
- Breed in soil
Cluster flies are named for their tendency to cluster together in large numbers, often invading homes in search of warmth during colder months.
- Long legs and mosquito-like appearance
- Do not bite or spread diseases
Crane flies are characterized by their long legs and a mosquito-like appearance. Unlike mosquitoes, they do not bite or spread diseases.
- Also known as scuttle flies
- Breed in decaying organic matter
Phorid flies are small, humpbacked flies often found around decaying organic matter and drains. They can move quickly, earning them the nickname “scuttle flies.”
- Found around meat and animal carcasses
- Can spread disease-causing bacteria
Flesh flies are attracted to and breed in decaying meat and animal carcasses. They can carry and spread harmful bacteria, posing a potential threat to human health.
- Biting insects that can transmit diseases
- Lay eggs in flowing water
Black flies are small, biting insects that can transmit diseases to humans and animals. They are often found near rivers and streams, where they lay their eggs.
- Also known as moth flies
- Breed in drains and sewers
Drain flies are small, fuzzy flies that resemble moths. They are commonly found in and around drains and sewers, where they breed in the organic material.
|Soil and waterlogged areas
|Decaying organic matter
|Meat and animal carcasses
|Drains and sewers
Flies exhibit a wide range of colors, from dull browns and grays to more vibrant hues like greenish-yellow and even metallic tones. For instance, adult hover flies often have black bodies with bands or stripes of orange, yellow, or white, resembling bees or wasps.
Flies also vary greatly in size. Some examples include tiny gnats, small to medium-sized deer flies (10-13 mm long), and larger horse flies (14-19 mm long)1.
Fly shapes can differ from robust to slender. Their heads are usually about the width of their abdomen or wider.
Large eyes are a common feature among flies, which enable them to have good navigational skills.
Some fly species have hairs on various parts of their bodies. These hairs can be sensory or provide insulation.
|Black with bands or stripes of orange, yellow, or white
|Small to medium (10-13 mm)
|Robust to slender, heads about the width of the abdomen
|Large, for good navigation
|Tinted smokey gray-brown or with dark patterns
|Can be sensory or provide insulation
Life Cycle and Reproduction
Fly larvae, also referred to as maggots, are the initial stage of flies’ development. They hatch from eggs, typically laid on decaying organic matter or animal waste. This stage usually lasts for about 8 to 17 days, depending on factors like food supply and weather conditions.
- Example: Female stable flies lay over 400 eggs during their lifetime, developing in soiled animal bedding or rotting grass clippings.
Maggots are worm-like and white, going through several stages of growth before pupating and becoming adults. In some species, maggots can complete their development in as little as 8 days, while others may require a longer period.
Feeding and Breeding Sites
Flies typically reproduce and feed in damp, moist areas or areas with decaying organic matter or waste. These breeding sites can include:
- Soiled animal bedding
- Rotting grass clippings
- Compost piles
- Garbage bins
- Sewage treatment plants
Some flies, like mosquitoes and stable flies, also feed on mammal blood.
|Garbage, decaying matter
|Animal waste, rotting vegetation
|Soiled animal bedding, grass clippings
|Mammal blood, nectar
In summary, the life cycle of flies is crucial to understanding their development, feeding habits, and breeding sites. Understanding these factors can help manage and control fly populations, reducing their impact on humans and animals.
True flies thrive in damp habitats and are most common in humid environments where moisture is abundant1. For example:
- In rainforests
- Near water bodies like lakes or streams
Flies can be found in various habitats supporting diverse wildlife, as they play a crucial role in maintaining the ecosystem2. Some examples include:
- Pollinating flowers
- Being a food source for other animals like birds and spiders
Flies often use drains as breeding sites due to the presence of organic waste3. As a result, proper drain maintenance can help prevent fly infestations. Some measures include:
- Regularly cleaning drains
- Ensuring proper disposal of waste
|Flowers, animal habitats
|Homes, public buildings
Impact on Humans and Environment
Biting flies can be a nuisance and cause discomfort to humans. Some examples include:
- Black flies
- Deer flies
- Horse flies
- Sand flies
The bites inflicted by these flies can be painful and itchy. For instance:
- Black flies may cause swollen and painful bites
- Horse flies can deliver particularly painful, sharp bites
Biting flies can transmit harmful diseases to humans, such as:
Infestations of flies, like house flies, can lead to unsanitary conditions and spread of diseases. Examples include:
- House flies: food poisoning and dysentery
- Fruit flies: contamination of fruits and vegetables
Some flies are considered beneficial insects. These include:
- Parasitic wasps: natural pest control for garden pests
- Tachinid flies: help control caterpillar populations
Flies also play a role in pollination. For example:
- Syrphid flies, also known as hoverflies, are important pollinators for plants
- Flower flies help in pollinating flowers in gardens and agricultural fields
|Painful bites, disease spread
|House Flies (Infestations)
|Unsanitary conditions, disease spread
|Beneficial Insects (e.g., Parasitic Wasps)
|Natural pest control, garden health improvement
|Pollinators (e.g., Syrphid flies)
|Plant pollination, enhance agricultural productivity
Fly Management and Control
Sanitation plays a vital role in managing fly infestations. An essential step includes maintaining cleanliness around your home and yard.
- Keep garbage bags tightly tied to reduce odor.
- Clean garbage cans regularly to remove food and odors.
- Use garbage cans with tight-fitting lids and place them as far away as possible from your home.
- Remove animal manure, rotting mulch, lawn clippings, and dead birds and animals from your yard.
By diligently keeping your environment clean, it helps to minimize fly breeding sites and prevent infestations.
Pest Control Methods
In addition to sanitation, implementing various pest control methods can effectively manage fly populations. Here are some practical, pesticide-free methods:
- Fly swatters – A handy tool to control individual flies that have entered your home.
- Vacuum cleaners – Efficiently remove large numbers of dead flies that have accumulated in attics or other areas.
- Traps – Various types of traps can be used to capture and kill flies, reducing their numbers.
- Biological control – Using beneficial organisms to manage pest species, such as commercially available organisms targeting immature stages of flies.
|Pest Control Method
|Simple and cheap
|Only kills one fly at a time
|Can capture many flies
|May be unattractive
|Less effective on adult flies
By implementing appropriate sanitation practices and a combination of these pest control methods, you can effectively manage and control fly populations in your environment.
The order Diptera comprises the true flies, which are insects characterized by having only one pair of wings1. With over 150,000 described species, Diptera is one of the largest groups of insects2. Flies can be further classified into various families based on their physical features and behaviors.
Identifying flies can be easier by examining their:
- Wing structure
- Leg structure
For instance, adult flies usually have either thin sucking mouthparts, like Mosquitos3, or sponging mouthparts, a tube with a wider sponge at the end, like Flower Flies and House Flies4. One of the most distinct features of true flies is the presence of halteres—small, club-shaped balancing organs located near the wings5.
Some common fly families include:
- Muscidae, commonly known as house flies
- Culicidae, which includes mosquitoes
- Syrphidae, or flower flies and hover flies
- Tachinidae, a group of parasitic flies
- Calliphoridae, commonly referred to as blowflies and bluebottles
When comparing different fly families, it’s helpful to consider the following table:
|Long and thin
|Robust and spiny
|Slender with bristles
In summary, flies belong to the Diptera order and are further classified into numerous families based on their characteristics. Their wing structure, mouthparts, antennae, and leg structure are some of the key features used for fly identification.
In the world of literature, there are several books and articles about different types of flies and their importance. Some publications focus on their biology, while others discuss their role in ecosystems. For example:
- “The Life of the Fly” by Jean-Henri Fabre
- “The Amazing World of Flies” by Alina Brucella
Technological advancements have helped researchers better understand the behavior and lifecycle of flies. Various devices like insect traps and monitoring systems have been developed to control their populations, especially in residential and agricultural settings.
Flies have been depicted in various forms of visual arts, ranging from close-up photography to paintings and illustrations. These artistic representations often emphasize their intricate body structures and vibrant colors.
Throughout history, flies have played a major role in shaping human civilizations. They have contributed to the spread of diseases, but have also been instrumental in pollination and decomposition processes.
On This Day in History
Flies might not directly relate to historical events, but their presence and impact can be explored within the context of past events, such as how they influenced pest control measures and agricultural practices.
Several online quizzes are available to test your knowledge about flies, their habitats, and their significance. Some examples include:
- The Ultimate Fly Quiz
- Can You Identify These Common Flies?
There are podcasts dedicated to discussing insects, including episodes that delve into the world of flies. Examples include:
- The Insect Hour: Flies
- Bug Talk: Fascinating Facts About Flies
For definitions and terms related to flies, an entomology dictionary can be a helpful resource. This will provide explanations for specific types of flies, their anatomy, and their behavior.
There are many entomologists and scientists who have dedicated their careers to studying flies. Notable figures include:
- Jean-Henri Fabre
- Paul Bert
To better understand the world of flies, you can find various articles and summaries that provide overviews of their life cycles, habitat, and importance in ecosystems. These resources offer a starting point for exploring the fascinating lives of these often misunderstood creatures.
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 Fly
Subject: Creepy bug in my house
Location: Ontario , Canada
July 17, 2015 10:18 am
Hi . Found this bug in my apartment and it freaked me out .. Kind of looks like a fly but it didn’t have wings …
This is definitely a Fly and it does not have any visible wings, but we don’t believe it to be a wingless species. We suspect it is either a mutant or that it has experienced some trauma that resulted in the loss of the wings, but we are posting your image in the event that someone with better identification skills than our own can provide a species name and a theory on the winglessness.
Letter 2 – Unknown Flies Emerge from hole in Texas
Subject: Unknown flies
Geographic location of the bug: Nolan,Tx
Time: 09:20 PM EDT
Your letter to the bugman: There was a paper wasp posted outside this hole so I assumed there was a nest inside. I am in the business of killing bugs, so I treated in the opening expecting wasps to come pouring out. To my surprise it was these flies. About 15 to 20 of them. I’ve never seen this species before.
How you want your letter signed: Scott
These are crazy looking Flies and the circumstances surrounding their discovery in a hole seem quite specific, but alas, Daniel’s initial perfunctory search turned up nothing. Daniel must attend to some personal matters at this time and he will return to do additional research into the identity of these interesting flies. Perhaps one of our readers will have some luck and write in with a comment.
Letter 3 – Unknown Fly from Arizona
Subject: Diptera mystery – what kind of fly is THIS??
Location: Phoenix, Arizona
March 17, 2017 5:39 pm
I am plagued in my apartment by these flies that are appearing out of nowhere, starting about two weeks ago. I kill them when I see them and I have already killed two “pregnant” females. In spite of my search, I cannot figure out the species and I need to know how dangerous they might to me and my pets. I tried to take a picture but the pic came out so badly, all you can see is a black blob. Here is what I know:
– they give birth to live maggots
– the maggots are snow white
-. Physically, they are built like blue bottle flies
– they are about 1/2 inch to 3/4 inch long
– completely black on the body, no markings are present and there is no iridescence
– large red eyes that do not touch
– noisy flyers ( in fact, that’s how I find them, I hear them before I see them)
– fast flyers and agile in flight
– attracted to light
– I noticed a few hairs on the upper body near the joint that attaches to the lower body; they appeared to be black
– wings are greyish and semi-translucent
I do have one dog and one cat, so animal waste is sometimes present, but I clean the litter box regularly and always change out the puppy pads immediately. I put the waste in sealed plastic bags which are scented, then put the sealed bags in a larger scented bag which I then tie shut until I take it out. My apartment smells like a combination of bleach and flowers. So what kind of fly likes this??
I don’t think they are flying in from outside; I think they are breeding inside. I can’t figure out where. If I can identify the species, maybe I will have an easier time finding out where and how they are reproducing and finally get rid of them. I never saw them or heard them until the start of March, when I finished my spring cleaning. Can they cause myiasis? If not, then how can the maggots survive in a clean apt? There numbers seem to be steadily increasing since I cleaned. I want to figure this out before I am completely infested with flies, yuck! All of my questions will be answered if I can figure out what this mystery species is. Please help me if you can!
Signature: Concerned in Arizona
Dear Concerned in Arizona,
We need a better image to make an identification. Louse Flies in the family Hippoboscidae give birth to live maggots, and they are pictured on BugGuide where it states: “Females rear one offspring at a time, the larva feeding in utero from special “milk” glands. The mature larva is ‘born alive’ and immediately pupates in the soil (or on the host in some cases). Most are host specific on bird species, with a few occurring on mammals.”
Thank you for your quick response! I’ve got one (that I saw – Lord knows how many there actually are) flying around my living room right now! I have locked myself in my bedroom and put duct tape over the door seams. I went out for one moment and it flew right at me! I was armed with nontoxic plant oil fly spray which kills on contact and sprayed right at it – that was the only thing that protected me. the spray repelled it long enough for me to run back in my bedroom, but didn’t slow it down. whatever it is, it sure is hardy. I misted my entire apt with permithrin/raid 48 hours ago but it is still here and active as ever!
I know – that pic is bad. I don’t think I can do any better though, because my phone camera is the only camera i have and my phone is cheap.
No, it can’t be that louse fly, because for the two females I’ve disposed of, they each had more than 5 maggots coming out. A single maggot getting born, somehow wouldn’t bother me like seeing 7-8 wriggling white protrusions from a black fly’s back end all struggling to break free at once. At least one fly with maggots was depositing bots in my bedroom. Hopefully, whatever bots she dropped are dead now…
I’m doing as much research as i can, and I’m guessing it’s a flesh fly of some sort… The only thing is that it is all black from what I could tell. And it seems attracted to me, but doesn’t match the description of any biting fly that I’ve read about.
I wonder if I should be worried about cutaneous myiasis, since flesh fly maggots eat both dead and living tissue.
I wonder if it could be a rarer fly that is not usually seen??
The mystery continues…
We are sorry, but we are unable to provide any further assistance.
Letter 4 – Unknown Fly from India
Subject: Which fly?
Location: Pune, India
March 27, 2015 9:39 pm
I came across this fly on the bark of a Mahogany tree.
It’s got a single pair of wings and measures about 2cms or so.
Any clues much appreciated.
Thanks & Regards,
We do not recognize your colorful Fly, but we will post the image in the hope that one of our readers will be able to assist in the identification.
Thanks for trying Daniel!
Letter 5 – Stiletto Fly from Israel
April 2, 2011 5:09 pm
what this bus
Signature: shimi eni
Dear shimi eni,
Your bus is a Fly and we do not recognize the Fly. We would like additional information before we attempt this identification.
Update: a few minutes later.
There are some beautiful Flies on the Diptera-Israel Insect World webpage, but nothing like this creature.
Identification Courtesy of Karl
April 8, 2011
Hi Daniel and shimi eni:
Someday, perhaps I will be able to take macro shots as nice as this one. It’s a Stiletto Fly (Therevidae), Xestomyzina aureostriata. As far as I can tell, the species has a very limited range and is perhaps endemic to Israel alone. I could find no other information regarding this particular species but Therevid flies generally prefer arid or semi-arid habitats. The larvae are typically soil dwellers that predate other soil invertebrates, particularly beetle larvae. Most adults feed on flower nectar. You can also check out additional photos here and here. Regards. Karl
Thanks so much for providing this information Karl. We have created a new subcategory just to house this awesome Stiletto Fly.
ERRATA: October 16, 2011 9:06 PM.
This is not a bus. This is a bug.
Letter 6 – Unknown Fly from Kenya
Location: Maasai Mara, Kenya
December 21, 2010 6:28 am
I’ve got a few more for you to identify.
All from Maasai Mara in Kenya
– Picture one: A tiny little insect about 1cm long. It seemed to float effortlessly above the grass
First, we are thrilled to be receiving your submissions from Kenya, but placing widely divergent species in a single email makes for problems with our already ponderous system for archiving. For posting purposes, we prefer only one species per letter. You do not need to attach three images to each email. We also noticed our inbox contains two additional emails from you today. It takes considerable time to format each letter with images for posting and that does not include research time. Interestingly, we also just posted a letter and photo of a Ghost Mantis from Kenya that was not supplied by you. We are confining the image on this post to just the unknown Fly and we hope one of our readers can supply any information on this black beauty with white spots.
Letter 7 – Unknown Fly from Malaysia
Subject: insect with metal collar and straw jacket
Location: Malaysia highlands
January 29, 2013 8:25 am
I bet you thought I was kidding around with the subject. My knees wobbled when I realised what I had captured. He was on night lamp so possibly nocturnal. he was tiny (about 1-2mm) so I didn’t realise what I had photographed until I looked in the camera display after the shot. I figured you’d either know exactly what it is because of its unusual look or at the very least you’d get as much of a kick out of it as I did. Thanks.
We don’t think we are able to do much more than provide an order and a sex. We believe this is a member of the insect order Diptera, so you could call it a Fly. Because of its antennae, we strongly suspect it is a male.
Letter 8 – Unknown Fly from Thailand
Some kind of fly?
Fri, Oct 17, 2008 at 6:02 AM
I spotted this small insect this afternoon in the garden. It’s about 8 mm long and first I thought it was some kind of beetle, but zooming in on the picture I think it’s a fly, but one with a very large tongue that moves like the trunk of an elephant 😉 I’ve checked out all the flies on your website, but can’t find this one. Hope you can give me a hint! Cheers, Monique
Koh Samui, Thailand
This is a fly, but we have no idea how to classify it beyond the order Diptera. We are reluctant to do any internet research at the moment as our internet connectivity is quite mercurial recently, and we never know from moment to moment if we will be able to connect. Time Warner, our internet provider, has been less than reliable lately. Perhaps a reader will be able to provide a more exact identification.
Letter 9 – Unknown Mating Flies
Location: Hawthorne, CA
July 19, 2011 2:22 pm
Hi – it’s me again. Can you tell me what type flies these are?
Signature: Thanks, Anna Carreon
They remind us a bit of Big Headed Flies in the family Pipunculidae (see BugGuide) though we have a sneaky suspicion that they are really Flower Flies in the family Syrphidae. This will take us a bit of research, and we may request assistance from Eric Eaton.
Letter 10 – Xenox tigrinus Mating
i just found these two in a hanging flower basket on my porch in the hudson valley, NY. What are they?
Not moths, but mating flies. We contacted Eric Eaton when we couldn’t find your insects on BugGuide. Here is what he has to say: “This is a pair of mating bee flies, Xenox tigrinus. Nice insects, much larger than Eurosta. Xenox are parasites of large carpenter bees. Eric “