How do I identify a type of fly?

Identifying the exact type of fly you are dealing with can be tricky. There are over 120,000 known species of flies in the world, and they can look very similar to each other. However, there are some key features you can look for to narrow down the possible fly species.

Check the Fly’s Size

The size of a fly can be a major clue as to what type it is. Here are some common fly sizes:

• Fruit flies – 2 to 4 mm
• House flies – 6 to 7 mm
• Blow flies – 8 to 14 mm
• Horse flies – 10 to 25 mm
• Crane flies – 10 to 60 mm

If the fly is very small, around 2-4 mm, it’s likely a fruit fly. Larger flies around 6-14 mm could be house flies, blow flies, or horse flies. Giant flies up to 6 cm are probably crane flies.

Examine the Fly’s Body

A fly’s body shape, coloring, and specific markings can also indicate its species.

• Fruit flies have a rounded, yellow-brown body and red eyes.
• House flies have a gray thorax with four dark stripes and an iridescent green/blue abdomen.
• Blow flies are metallic blue or green in color with a dark gray abdomen.
• Horse flies are large with dark colors like gray or black and often have green or yellow eyes.
• Crane flies have very long legs and a slender, mosquito-like body.

Take note of any patterns, colors, or unique physical features that stand out on the fly’s body when making an identification.

Look at the Wings

A fly’s wings can also help distinguish one species from another. Some details to note:

• Fruit flies have uniform grayish wings.
• House flies have clear wings with light and dark bands.
• Blow flies have a spotted pattern on their mostly clear wings.
• Horse flies have clear or cloudy patterned wings with dark bands.
• Crane flies have long, slender wings that are either clear or grayish.

The venation (vein patterns) in the wings can also help identify the type of fly, although this requires very close inspection.

Note Leg and Body Hair

Some flies have more hair on their bodies and legs than others:

• Fruit flies have translucent legs and body with almost no hair.
• House flies have spongy, bristly legs and hairy bodies.
• Blow flies have stout, bristly legs and a furry thorax.
• Horse flies have stout, bristly legs with horizontal stripes.
• Crane flies have very long, thin legs with little hair.

Paying attention to the amount and location of hairs can be a helpful identifying feature for some fly species.

Listen for Buzzing

Believe it or not, the sound a fly makes while flying can provide clues to its identity. Here are some buzzing notes:

• Fruit flies are very quiet, producing only a faint high-pitched hum.
• House flies make a loud buzzing noise in flight.
• Blow flies are also loud, buzzing flies.
• Horse flies make a low-pitched buzzing compared to house flies.
• Crane flies are silent fliers, not making any buzzing noise.

In general, the smaller the fly, the higher pitch its wing buzz will be.

Look at Behavior and Habits

Paying attention to where a fly is found and how it behaves can confirm what species it is:

• Fruit flies congregate around ripe fruits and vegetables, especially bananas, tomatoes, and onions.
• House flies live around humans, in homes and buildings, feeding on garbage and waste.
• Blow flies flock to animal feces or carcasses to lay their eggs.
• Horse flies bite livestock and other mammals to feed on blood.
• Crane flies are found around marshes and wooded areas.

Think about where the fly was found and what it was doing when spotted. This can validate what species it is likely to be.

Examine the Mouthparts

Looking extremely closely at a fly’s mouthparts with a magnifying glass or microscope can also help identify the species.

• House flies have sponging mouthparts for absorbing liquid foods.
• Blow flies have mouthparts similar to house flies.
• Horse flies have sharp, cutting mouthparts for slicing into skin.
• Fruit flies have sucking mouthparts like mosquitoes.
• Crane flies have very small or obscure mouthparts as they don’t eat.

Assessing the exact shape and design of the fly’s mouthparts takes very close inspection but can help confirm the fly species.

Conclusion

Identifying a fly is easiest when you look at multiple characteristics-size, body shape and color, wing pattern, leg hair, mouthparts, buzzing sound, behavior, and where it’s found. Start by noting the most obvious features first like size and color. Then look closer at details like wings, legs, and mouth shape if needed to differentiate between similar species. With practice, you’ll begin recognizing the most common house, fruit, and other fly species at a glance.

Fly Identification Charts

Fly identification can be tricky, but using visual charts can make it easier and more accurate. Here are some helpful fly identification diagrams and infographics:

Common Household Flies of North America

This chart shows illustrations of the most common flies found inside homes in North America. It displays relative size, colors, wing features, and names to distinguish fruit flies, cluster flies, house flies, and more.

Types of Flies

Here is a visual guide to help identify over a dozen common fly species by location, characteristics, and habits. It covers fruit flies, phorid flies, moth flies, and other pesky fly varieties.

Flies that Bite Humans

This infographic focuses on types of flies known to bite humans like horse flies, black flies, midges, and mosquitoes. It shows where they are found and what their bites look like.

Blow Flies Life Cycle

Here is an illustrated guide walking through the distinct life stages of blow flies from egg to larva to pupa to adult. It highlights key facts and details about each phase of development.

Horse Fly vs Deer Fly

This chart compares and contrasts horse flies vs. deer flies. It outlines physical differences, habitats, and feeding behaviors to identify which painful biter is after you.

Mosquito Identification

This diagram walks through identifying details like wing scales and leg bands to differentiate Culex, Anopheles, Aedes, and other types of mosquitoes around the world.

Using visual fly identification charts like these examples can make distinguishing between the thousands of fly species much more simple and straightforward.

Collect a Fly Specimen for Identification

If you are still struggling to identify a fly after using identification guides, consider collecting a specimen to show an expert. Here is a simple protocol for fly collection and submission for identification:

Supplies Needed

• Glass or plastic jar/vial
• Rubbing alcohol
• Tape
• Marker
• Tweezers or collection net

Collection Steps

1. Use a net or tweezers to capture the live fly specimen.
2. Place the fly in a clean jar or vial. Plastic is safest if glass breaks.
3. Fill the container with enough rubbing alcohol to submerge the fly.
4. Seal the container tightly with a lid or tape.
5. Label the container with collection date, location, and other details.
6. Store the container in a cool, dark location until ready to submit for ID.

Submission Tips

• Contact a local university entomology department about identifying the fly from your specimen.
• Natural history museums sometimes accept insect specimens from the public too.
• Double-check submission guidelines and include all requested info like date/locale.
• Pack the container carefully to prevent damage during shipping if mailing it.
• Be aware there may be a fee charged for identification services.

With an intact specimen, an expert can use microscopy, guides, and databases to conclusively identify the fly down to species level. This provides a definitive answer when self-identification proves challenging.

Set Out Bait Traps to Monitor Flies

In addition to collecting a single fly, setting out bait fly traps can help survey the types of flies frequenting an area over time. Here are some tips for baiting fly traps:

Trap Types

• Jar traps – Simple open jar with bait inside
• Paper cone traps – Cone funnel into jar/bottle
• Bottle traps – Cut bottle with inverted neck
• Sticky traps – Glue boards or tape to catch flies

Bait Ideas

• Overripe fruit – Bananas, pineapple, tomatoes
• Apple cider vinegar
• Beer or wine
• Maple syrup
• Decaying meat
• Commercial fly attractants

Trap Placement

• Outdoors near gardens, composts, etc.
• Near potential indoor entry points
• Areas where flies are frequently spotted
• In warmer, more humid locations
• Away from strong winds and rain

Checking traps daily and renewing bait allows observation of the types and numbers of flies in that habitat over time for better understanding of populations and behavior patterns.

When to Seek Professional Help with Identification

Even with the best identification guides and tools, some flies can still prove difficult for non-experts to differentiate. It may be wise to enlist professional help with fly identification if:

• You find a fly that doesn’t match common species in your area
• A fly infestation persists despite control efforts
• You need to document fly species accurately for legal/medical purposes
• The fly could indicate a serious health hazard like sewage leaks
• You are considering major preventative measures and want ID confirmation
• The fly is suspected to be a non-native, invasive species

Licensed pest management professionals have specialized expertise in identifying all types of insect pests, including flies. They also have access to powerful microscopes and diagnostic resources beyond what the public can easily access. Calling in an expert provides peace of mind and may be required for certain situations involving unidentified fly species.

Frequently Asked Fly Identification Questions

What are some tips for photographing a fly to help with identification?

When photographing a fly to assist with ID, try to get close-up shots from multiple angles showing key features like wings, body patterning, legs, eyes, and mouthparts. Use good lighting and the highest resolution camera available. Keep the fly motionless and in focus. Take pictures against a clean, simple background.

Where can I find a guide to fly anatomy to help understand identification terminology?

Many online entomology resources have diagrams labeling parts of a fly’s body, wings, legs, eyes, mouth, antennae, and other structures. Knowing basic fly anatomy like thorax, abdomen, halteres, femur, and tibia helps decipher species descriptions for identification.

What are some common pseudopod larval flies often found in drains?

Drain fly larvae belong to the Psychodidae family. The most common genera with a pseudopod larval stage that breed in drains and pipes are Psychoda and Clogmia flies. Proper drain cleaning is needed to remove their biofilms.

How can I attract certain flies to aid in identification?

Put out bait traps with foods that target the desired fly. For fruit flies use overripe produce, for fungus gnats use damp soil, for blow flies use rotting meat, and for many flies use fermenting sugar solutions. Then observe what is attracted.

Why are some flies like hoverflies harmless but others like horse flies bite painfully?

Hoverflies and other syrphid flies have no biting mouthparts. However horse flies, black flies, and mosquitoes females have piercing mouthparts to feed on blood for egg production, making their bites painful.

Conclusion

Identifying an unknown fly can be complicated, but with some close observation of size, shape, color, wings, markings, sounds, behaviors, and other characteristics, you can usually narrow down the possibilities to a fly family or genus. Understanding where flies are located and what they are doing provides important context clues. Photography and collecting samples to examine under magnification or submit for professional ID may be necessary for tricky specimens. With keen observation skills and the right identification resources, putting a name to pesky flies becomes much easier.