Crane flies are fascinating insects often mistaken for giant mosquitoes due to their slender bodies and long legs. While they may look intimidating, you’ll be relieved to know that crane flies are harmless and do not bite or transmit diseases. They can be found in various environments, usually around water, and are most active during spring and summer.
There are hundreds of species of crane flies, each showcasing slight differences in appearance and habitat preferences. For example, the common crane fly has a brown or gray color and can be found around landscape plants and outside buildings, attracted by light. On the other hand, the invasive European crane fly is slightly larger, and its larvae can cause damage to lawns and turfgrass.
In this article, you’ll be introduced to the many types of crane flies, their identifiable features, and the intriguing characteristics of these benign insects. By developing your understanding of these fascinating creatures, you can better appreciate their role in the ecosystem and coexist peacefully with them in your backyard or garden.
Understanding Crane Flies
Crane flies are fascinating insects that belong to the family Tipulidae and order Diptera. They are often called “mosquito hawks” due to their slender, mosquito-like appearance. However, it’s important to note that crane flies do not bite, and they are not a type of mosquito at all1. You might be interested to know more about the different species of crane flies, their distinguishing features, and their habitat. Here’s a brief overview to help you understand these insects better:
Crane flies are known for their long and delicate legs. They can vary in size, with some adults reaching up to 1.2 inches in length2. Typically found near water, these insects are not only harmless but also play vital roles in their ecosystems as decomposers and a food source for other creatures.
There are hundreds of species of crane flies present in North America3. They exhibit various colors such as tan, gray, or greenish hues. Identifying specific crane fly species might be challenging due to their similarities. A few of the identifying features of crane fly larvae include a definite head, plump and segmented bodies, and fleshy projections at their hind end3.
It’s important to understand that some crane fly species have different life cycles and generations. For example, the marsh crane fly has multiple generations per year, whereas the common European crane fly has just one4.
Crane flies are considered beneficial insects that contribute to the decomposition process in their habitats. They help recycle nutrients back into the ecosystem and serve as a food source for various predators. While crane flies do not pose any threat to humans, their larvae can sometimes cause damage to lawn grass, which might require management5.
In summary, crane flies are fascinating insects with a wide range of species and distinctive features. Knowing more about these creatures can give you a better appreciation for their role in nature, despite their resemblance to the less-loved mosquitoes.
Life Cycle of Crane Flies
The life cycle of crane flies consists of four stages: egg, larva, pupa, and adult. It begins when adult crane flies lay their eggs in moist soil.
Eggs: In this stage, crane fly eggs are small and laid in clusters. They typically hatch within a few weeks, depending on the temperature and moisture levels.
Larvae: When the eggs hatch, crane fly larvae (known as “leatherjackets”) emerge. These larval crane flies feed on decaying organic matter, plant roots, and occasionally other insects. During this stage, they undergo several molts, growing larger each time. They often overwinter in this stage, meaning they spend the cold months as larvae. Here are some characteristics of crane fly larvae:
- Cylindrical, legless, and elongated bodies
- Grayish-brown in color
- Can be up to 2 inches in length
Pupae: After the larval stage, crane flies enter the pupal stage. They form a protective cocoon where they undergo complete metamorphosis. This stage doesn’t last too long compared to the larval stage; it usually takes about two weeks.
Adults: Finally, adult crane flies emerge from their pupae. They are delicate, long-legged insects with two functional wings. Adults are typically poor fliers and are often seen resting on vegetation. You may notice their resemblance to oversized mosquitoes, but don’t worry; they don’t bite or sting! Here are some features of adult crane flies:
- Gangly, long legs
- Two large, functional wings
- Thin, elongated body
- Length of about 1 inch
In conclusion, the life cycle of crane flies is a fascinating process that underscores the variety and adaptability of these insects in diverse environments. Knowing more about their life cycle can help you better understand their role in the ecosystem and may assist in developing management strategies if needed in gardens or lawns. Learn more about managing crane flies in lawns here.
Feeding and Diet
Crane flies are diverse creatures that can have varying diets depending on their life stage and species. As larvae, they primarily feed on organic material and plant roots. In some cases, they might consume aquatic insects and decaying vegetation.
Adult crane flies, on the other hand, have a different dietary preference. They usually feed on nectar from various flowers, providing them with the necessary energy for a short period. It’s worth mentioning that some adult crane flies don’t feed at all, relying on previously stored energy from their larval stage.
To give you a clearer picture, here’s a quick comparison table:
|Larvae||Organic material, plant roots, aquatic insects, decaying vegetation|
|Adult||Nectar (some species might not feed)|
Remember, crane fly larvae can be useful for breaking down decaying plant matter and enriching the soil, while adults primarily have a role in pollination. So next time you see these interesting insects, appreciate the various roles they play in our ecosystem.
Crane Flies in the Ecosystem
In the ecosystem, crane flies play a valuable role as both predators and prey. Their larvae, known as leatherjackets, feed on decaying plant material, algae, and other small invertebrates found in moist soil and freshwater habitats. As a result, they contribute to nutrient recycling and promote overall ecosystem health.
- Moist soil environments: marshlands, streams, and riverbanks
- Aquatic ecosystems: freshwater sources that support invertebrate life
- Main prey: decaying plant material, algae, and small invertebrates
Adult crane flies, though they look like giant mosquitoes, do not bite humans or other animals. Instead, their short-lived adult stage is dedicated to reproduction. As such, they become food for a variety of birds, amphibians, and other predators.
- Examples of predators: birds, frogs, and spiders
- Adult crane flies feeding habits: they primarily feed on nectar
One noteworthy species, the marsh crane fly, was discovered more recently in the Pacific Northwest. It has multiple generations a year, compared to the single generation of the common European crane fly. Both species are considered European crane flies due to their shared origin, appearance, and the similar damage they cause to lawns and turfgrass.
In conclusion, crane flies serve an essential function within their ecosystems. They act as both predators and prey, supporting diverse food webs and contributing to overall ecological balance.
Physical Characteristics of Crane Flies
Crane flies are fascinating insects, often mistaken for large mosquitoes due to their physical similarities. Let’s take a closer look at their features.
Size: Adult crane flies can range from tiny to almost 1.2 inches long. Their size depends on the species, as there are hundreds of species of crane flies in North America.
Color: Their bodies are commonly found in shades of brown, gray or even greenish. You may notice variations in color depending on the specific species you observe.
Body structure: Crane flies possess a slender, cylindrical body that is divided into three main segments – the head, the thorax, and the abdomen.
Wings: These insects belong to the order Diptera, which means they have two wings. Their wings can be quite delicate, and their wingspan varies based on their size and species.
Legs: One of the most notable features of crane flies is their extremely long legs. These legs are very fragile and can break off easily. They use their legs to navigate around, though their flying abilities are quite slow.
Head: The head of a crane fly houses its large, compound eyes and a pair of small antennae.
Scales: Unlike mosquitoes, crane flies do not have scales on their wings.
Now that you have a better understanding of crane flies’ physical characteristics, you can easily distinguish them from similar insects, such as mosquitoes. Don’t forget that these harmless creatures are often found near water and shouldn’t be a cause for concern in your environment.
Common Types of Crane Flies
In this section, we will discuss some common types of crane flies that you might come across. Crane flies belong to the Tipulidae family and are often mistaken for giant mosquitoes due to their appearance.
Tipula sp, also known as European crane flies, are one such common type. They can be identified by their slender bodies and long, fragile legs. Although they resemble mosquitoes, they do not bite and are actually harmless. Interesting fact, the European crane fly has only one generation per year, while its cousin, the marsh crane fly, has multiple generations a year source.
Another type you might encounter is the leatherjackets. Leatherjackets are the larvae of crane flies, typically found in the soil close to the surface. They are mostly tan, gray, or greenish grubs with a distinct legless appearance source.
Ctenophora sp, also known as ‘daddy-long-legs,’ is another type of crane fly. These are characterized by their extremely long legs, giving them their unique nickname. Adult crane flies in this category can range from tiny to almost 1.2 inches long source.
Here is a comparison table of some common types of crane flies:
|European||Slender body, long legs, mosquito-like||One generation per year|
|Marsh||Similar to European, multiple generations per year||Multiple generations per year|
|Leatherjackets||Tan, gray, or greenish grubs||Larvae stage of crane flies, found in soil|
|Ctenophora sp||Extremely long legs||Also known as ‘daddy-long-legs,’ up to 1.2″ long|
Remember, crane flies are mostly harmless, and their presence typically does not pose a threat. However, managing their population in lawns and other areas is essential for maintaining turfgrass health source.
Crane Flies vs Mosquitoes
Crane flies and mosquitoes are two types of insects that can be easily confused since they share similarities in shape and size. However, they have some critical differences. Let’s explore these differences to help you easily identify them.
Appearance-wise, crane flies are like giant mosquitoes with a slender body and very long legs. On the other hand, mosquitoes have a shorter body and legs. Crane flies have larger wings, while mosquitoes have smaller ones with a distinct pattern of scales. For the mouthparts, mosquitoes possess a long, slender proboscis, whereas crane flies have an elongated face with mouthparts at the tip.
- Crane Fly:
- Slender body
- Very long legs
- Larger wings
- Elongated face with mouthparts at the tip
- Shorter body and legs
- Smaller wings with scales
- Long, slender proboscis
Now let’s compare their larvae. Crane fly larvae are tan, gray, or greenish grubs with a definite head and tiny, fleshy projections at the hind end. Mosquito larvae, on the other hand, are wriggling, elongated organisms with a dark siphon tube at the end of their body for breathing.
When it comes to behavior, crane flies are mostly harmless and can be found around water like the adult ones. In contrast, mosquitoes are infamous as disease carriers, transmitting viruses such as Zika, dengue, and malaria. Mosquitoes also cause itchy, irritating bites. Crane flies do not bite or carry diseases.
In summary, while both crane flies and mosquitoes may seem similar, their appearance, larvae, behavior, and impact on human health differ significantly. Understanding these distinctions will help you recognize and address their presence effectively.
Predators and Threats
Various natural predators feed on crane flies and their larvae, helping to control their population. Among these predators, you’ll find spiders, bats, and arthropods such as centipedes and millipedes.
Spiders, for example, are highly efficient in capturing adult crane flies by trapping them in their webs. Bats, on the other hand, catch these creatures while they’re flying. These nocturnal mammals possess excellent echolocation skills, allowing them to detect and pursue their prey, including crane flies.
When it comes to arthropods that prey on crane flies, centipedes and millipedes are particularly noteworthy. They crawl on the ground and feed on crane fly larvae, especially those hiding in damp soil or decaying vegetation.
A few other predators that occasionally consume crane fly larvae include skunks and “skeeter eaters” (also known as mosquito hawks). Skunks dig in lawns to find various insects, and they may stumble upon crane fly larvae while foraging. Skeeter eaters, despite their name, are not efficient at controlling mosquito populations. However, they do play a role in keeping crane fly populations in check.
Ticks, as external parasites, typically do not prey on crane flies or their larvae. However, they might target larger animals that come into contact with them.
In summary, a variety of predators contributes to maintaining crane fly populations by feeding on them in different stages of their life cycle. Each predator has its unique hunting strategy, and their combined efforts help to keep crane flies under control in their environment.
Crane Flies Control Methods
Keeping your lawn healthy is essential in preventing crane fly infestations. There are several ways you can control these nuisance pests and maintain a beautiful lawn.
In both spring and fall, you can take measures to get rid of crane flies. For instance, removing excess thatch is crucial, as it provides an ideal habitat for larvae, which feed mostly below the thatch layer. When managing your lawn, consider the following:
- Choose turfgrass species that adapt to shady or low sunlight areas, as growing them in full sun can promote crane fly survival.
- Proper irrigation can keep the lawn healthy and discourage crane fly growth.
Another method to control crane flies is using biological agents like nematodes. These microscopic worms are harmless to plants and humans, but they parasitize crane fly larvae, reducing their population. You can apply nematodes to your lawn during spring or fall when the crane fly larvae are most active.
For severe infestations, you might need to resort to insecticides. Apply products containing active ingredients like chlorantraniliprole or imidacloprid. However, using insecticides can be harmful to other beneficial organisms in your lawn. Always read and follow the product label instructions for safe and efficient application.
Crane flies may also enter your home, but you can easily prevent this by installing window screens. This will not only keep crane flies away, but also other flying insects that may cause a nuisance.
To summarize, controlling crane flies in your lawn involves proper turfgrass management, using nematodes, applying insecticides when necessary, and putting up window screens. All these methods will help keep your lawn and home free from these pesky insects.
Crane Flies and Their Impact on Turf and Pastures
Crane flies are often mistaken for mosquitoes due to their long legs and slender bodies1. However, they do not bite and can actually have an impact on your turf and pastures.
Crane fly larvae feed on the roots of turfgrass2. This can lead to:
- Thinning of turf
- Patchy, uneven lawns
- Weakened grass more susceptible to other pests and diseases
To manage crane flies in your lawn, it’s crucial to:
- Monitor for adult crane flies in late summer and fall
- Treat infestations promptly
- Water or irrigate turf soon after treatment1
Effects on Pastures
Crane flies can also affect pastures1, but their presence may be less noticeable than in lawns:
- Damage from crane fly larvae feeding on grass roots
- Potential loss of grazing resources if crane fly populations are high
Overall, it’s essential to be aware of crane flies and their potential impact on your turf and pastures.
Crane Flies in North America
In North America, there are over 1,600 species of crane flies. These insects have a mosquito-like appearance with slender bodies and long legs, but they are not actually mosquitoes. You might see them near water sources, as they are generally found around those areas.
Most crane flies are considered harmless and merely an occasional nuisance. However, a few species feed on grass roots, which may cause issues for your lawn or garden. In the Pacific Northwest, the marsh crane fly (Tipula oleracea) and the common European crane fly (Tipula paludosa) are two invasive species known for damaging turfgrass. These species originally came from Europe and northern Africa but have now spread throughout much of North America.
Adult crane flies range in size from tiny to almost 1.2 inches long. Their larvae appear as tan, gray, or greenish grubs – plump and segmented caterpillars without legs. Some key features of crane fly larvae include:
- A definite head
- Tiny, fleshy projections at the hind end
- A visible dark line (digestive tract) under the translucent body covering
During the spring and summer, you may notice an increase in crane fly activity. They are typically attracted to light and can often be found outdoors on buildings or screened windows. Keep an eye out for these unique insects, as they are a fascinating part of the North American ecosystem.
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 – Leather Jackets emerge after rain
Leather Jackets in Silver Lake
February 8, 2010
Hi–I live on a steep hill adjacent to the Silver Lake Reservoir. On Saturday after the heavy overnight rain I encountered lots of Leather Jackets writhing on the pavement. I am attaching three images. Which kind of Leather Jackets/Crane Flies are these? Native? Thanks so much.
Silver Lake, Los Angeles
Chen Young, an expert in the Crane Fly family, just wrote to us regarding the other two recent Los Angeles area emergences of Leather Jackets, and they were determined to be native. According to his description, your Leather Jackets are also the larvae of native Crane Flies. Chen has promised to send us an image of the European Crane Fly Larva for comparison.
Letter 2 – Leather Jacket: AKA Crane Fly Larva
Subject: Found in a creek water fall???
Geographic location of the bug: Folsom, California (summer)r
Time: 04:43 PM EDT
Your letter to the bugman: OMG! Founds this in a creek while camping in Folsom and it looks like some horror movie leech! Please know what thos is s I I can breath easy and be able to go back in the water here.
How you want your letter signed: Sicerly, Michael Del Carlo
This sure looks to us like the larva of a Crane Fly in the family Tipulidae, and you can compare your individual to images posted to Trout Nut, an anglers’ website. Here is a BugGuide image. We first read the common name Leather Jacket for Crane Fly larvae in Insects of the Los Angeles Basin by Charles Hogue. Though it somewhat resembles the “graboids” from Tremors (see Monster Legacy) we assure you the Crane Fly larva is perfectly harmless.
Letter 3 – Leather Jackets and Craneflies
Here are several pictures of invertebrates that my wife has taken. She is a sales rep for a company that sells garden products and she uses the pictures to train garden center employees to identify local pests. First, is a grub I found in my front yard here in Vancouver, Washington. It was about an inch long. My wife doesn’t know what it is. Any ideas? The next two are photos of a slug, one in front of a measuring tape. Nearly 10 inches long! What a beaut. The last two are European crane fly, in the adult and larval stages, respectively. Just something to add to your collection.
Thanks for all the awesome images. We are starting a new page devoted to snails and slugs thanks to your great images of a Banana Slug. We aren’t sure exactly what your grub is, but it is a type of scarab. We love the image of the larval Craneflies, known as Leather Jackets.
Letter 4 – Leather-Jacket
Dear Daniel, I was almost certain that this was a land planarian because of the triangular shaped head. I found it under a log and it moves like a slug. I contacted an expert on land planarians and he said this "thing" may be a larva of some sort, but definitely not a land planarian. Any ideas?
I agree with the expert, definitely not a planarian. They are flatworms. It might be some sort of a moth caterpillar. I wish you had a side view of it. How long was it? What about legs? Caterpillars usually have legs. Probably my best guess is a Crane Fly (Tipuloidea) larva, known sometimes as "Leather Jackets". They are often found on dry land in decaying vegetation. The larva of Tipula abdominalis looks like your photo.
Hi again. I guess it was about an inch long. I didn’t see any legs, but it was moving through that slimy stuff, so I guess they could have been there. I really thought I was seeing a worm or slug not a larva but you know I am not too good at this yet. Anyway thanks for pointing me in a general direction!
Letter 5 – Leather Jackets dislike the rain
Grey larva/caterpillar crawling out of soil after rain.
February 6, 2010
We had these little guys swarm out of our recently weeded soil after it rained. They are about 1 to 1.5 inches long, grey with black short stripes, with a four-pronged tail they looks like a faux-face. Could they be some sort of beetle grub?
Los Angeles, CA
Hi Mary Jane,
These are the larvae of Crane Flies, and they are called Leather Jackets. You didn’t indicate what part of Los Angeles this happened, but we received reports in January of Leather Jackets in large numbers from Van Nuys and Canoga Park. We then received a comment that they might be the invasive introduced European Crane Flies, Tipula paludosa and Tipula oleracea. We are not qualified to make the species call on your Leather Jackets, which might be an invasive introduced species, or they may simply be one of the numerous native Crane Flies. We may try to contact Chen Young who runs the Crane Flies of Pennsylvania website to see if he can determine if they are native or exotic.
Wow, thanks! I live close to the Highland Park/Eagle Rock area of Los Angeles. We did have quite a few crane flies over the summer. It was creepy having so many (hundreds) crawl out of the soil.
Thanks for your time!
Chen Young responds
February 6, 2010
Good to hear from you. I have looked both of the images and none of them are the introduced European crane flies. Noticed the middle lobes of the larvae are very dark and sharp which is not the character for the European crane flies. The middle two lobes of the European crane fly larvae are soft and flesh like. I don’t have an image with me now at home but I will send you one Monday when I get to work at the museum. By the way, we are having a big snow storm and everything is closed for that matter thus I don’t think I will venture out to the museum to get the image.
As for adult flies you can also check here http://iz.carnegiemnh.org/cranefly/tipulinae.htm#Tipula_(Tipula)_paludosa for comparison of the two species. These two species have also been reported recently in Michigan, New York, New England states, and Utah. It will eventually in Pennsylvania.
Okay, I will send you image of the European crane flies on Monday.
Letter 6 – Crane Fly, not Hanging Fly, from Costa Rica
Is this Bittacidae or Diptera? Or something else?
Location: unknown (will provide if later discovered) Ed. Note: Montezuma, Costa Rica
December 17, 2011 11:56 pm
My first guess is Bittacidae, but I’m used to seeing them with much thicker legs and longer antennae. The beak also looks unusual for a hangingfly and I can’t tell if it’s wingless. If it’s winged, most winged species rest their wings in a roof-like fashion (with the exception of Hylobittacus apicalis).
If you don’t know the location, does that mean you did not take the photo? Are you able to provide permission for us to post the photo? We would also need assistance and we do not want to have the photographer contact us in the future to remove the image.
The photo was taken in Montezuma, Costa Rica. The photographer is looking for an ID and is familiar with and is okay with the photo being posted on whatsthatbug.com. He has already posted the photo on another public forum:
Thanks for getting back to us so quickly Joseph. We agree with you and with several of the folks on the other public forum that this appears to be a Hanging Fly in the family Bittacidae which is represented by individuals on BugGuide that have more substantial legs. We would not rule out a Crane Fly. We will try to contact Dr. Chen Young at Carnegie Museum of Natural History and the Crane Flies of Pennsylvania website to see if he can provide anything conclusive.
Chen Young Responds
It is always nice to hear from you because your image always put a challenge to me and I like it.
This one is in the genus Orimarga, a small slender crane fly.
Happy holidays to you and your viewers.
Letter 7 – Insect in Amber: Polymera Crane Fly
Subject: Is this a cranefly?
Location: Amber from Chiapas, Mexico
January 24, 2013 12:45 am
Hi there. At first, I thought that this was a cranefly, but the long antenna have left me doubting. I realize that the images are not that great, but do you have any ideas. The body is about 5-6 mm long. Thank you for you help and for the great site.
Thank you for posing such an intriguing question. This does appear very much like a Crane Fly, and it appears to have a single pair of wings, but you are correct about the antennae being longer than modern Crane Flies. According to the Crane Flies of Pennsylvania website: “The antennae are composed of a cylindrical scape, a subspherical pedicel and 3 (Chionea) to 37 (Gynoplistia) flagellum segments (flagellomeres), commonly 11 in Tipulinae and 12-14 in Limoniinae in the Nearctic Region.” Perhaps the characteristics found in your fossil insect have been lost through the evolutionary process. We do not feel skilled enough to come to a conclusion, so we have written to Crane Fly expert Chen Young as well as Eric Eaton to get their opinions.
Chen Young confirms Crane Fly, genus Polymera
How about that! A fossil crane fly in the genus Polymera!!! I am attaching an image of a modern day Polymera to show you the similarity of these two specimens, notices the long antennae in the extant species.
What is the fate of this piece of fossil? I would like to send the image of this fossil with locality (if you have) to a colleague of mine, Dr. Sigitas Podenas from Lithuania, who works on fossil crane flies.
Thanks so much for the speedy response Chen. We will write back to Daniel who submitted this image and we will copy you with your requests. Hopefully he will be gracious enough to respond.
Wow! You guys are fast. Thank you so much for the identification. It’s nice of you to clear up this mystery for me.
The piece was found near Simojovel, Chiapas, Mexico, and I currently have it in my possession (in Mexico). I would be happy to try to take some better images of it for Dr. Podenas if he finds it of interest. I say “try” because my equipment is limited to a hand-held camera and a jeweler’s loupe.
Again, thank you for your help and kind reponse.
Letter 8 – Leather Jacket is Crane Fly Larva
Subject: What is this grub?
Geographic location of the bug: Mill Creek, Washington
Time: 12:49 PM EDT
Your letter to the bugman: Hello,
I have come across this little guy multiple times over the years when in the yard weeding and am curious what it is. Any info would be appreciated.
How you want your letter signed: Kristen
We believe you have encountered the larva of a Crane Fly like the ones pictured on BugGuide and again on BugGuide and you may read about them on the Missouri Department of Conservation site. Charles Hogue in his book Insects of the Los Angeles Basin calls Crane Fly larvae Leather Jackets because of their “thick dark skin.” Capital Regional District uses the name Leatherjacket.
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 – Mating Crane Flies, Flower Flies, Japanese Beetles and Ambush Bugs
Hi, my name is Brigette and I love your site. I’ve been interested in insects since I was a little kid, and am currently an undergrad studying entomology at McGill University. I love to photograph insects and thought you might enjoy some additions to your ‘bug love’ section. These were taken in my backyard in upstate NY.
|Crane Flies||Flower Flies|
I have included some japanese beetles, craneflies, horseflies, and ambush bugs (my favorites!). I even have some eggs as a result of the ambush bug matings, I kept several during the fall months. When introduced the males waste no time at all getting busy!
|Japanese Beetles||Ambush Bugs|
Wow!!! Thanks for sending us all your wonderful Bug Love images. They are most excellent.
Wondering if those really ARE mating Horseflies….
Lisa and Daniel: HAPPY NEW YEAR, and thanks for your site, it’s great. The “mating bugs” quartet has two happy Dipterans that are identified as “Horseflies,” but I wonder if they really are. For some reason they strike me more as Hoverflies or something else. The sender, being a budding entomologist, has great credibility, but somehow my mental antennae are quivering…so I’ll watch the site and see if there’s re-thinking on this one. regards from non-wintery Wisconsin,
We tried finding a species match under Horse Fly on BugGuide to no avail. We believe the eyes indicate Horse Flies. We will check with Eric Eaton. Eric made the following correction: “The mating horse flies are actually Flower Flies in the family Syrphidae, probably in the Erastilini tribe.”