Do Tiger Bee Flies Bite? Debunking Myths

Tiger bee flies are fascinating insects that many people encounter around wooden structures such as fences and roof overhangs.

They are known to parasitize the larvae of carpenter bees, but one common question is whether or not they bite humans.

While their appearance may seem intimidating, the good news is that tiger bee flies do not bite or sting humans.

In fact, their mouthparts are not designed for that purpose.

So, when you encounter these interesting insects, you can admire their unique wing markings and behavior without worrying about being bitten.

Tiger Bee Fly Overview

Physical Characteristics

The tiger bee fly, also known as Xenox tigrinus, is a unique species of insect.

Compared to other insects, it resembles a bumble bee due to its coloration but is in fact harmless. Here are some key features:

• Distinctive wing markings
• Mimics bumble bee appearance
• Does not bite or sting

Habitat and Distribution

Tiger bee flies can be found throughout North America, particularly around wooden structures and surfaces.

They parasitize carpenter bee larvae, hovering near their nests. Examples of tiger bee fly habitats include:

• Wooden privacy fences
• Wooden roof overhangs
• Decaying trees

They are not native to the UK, so tiger bee fly sightings in this region are quite rare.

Life Cycle and Behavior

Reproduction and Larvae

Tiger bee flies (Xenox tigrinus) are parasitic flies known for their unique life cycle involving carpenter bees.

Female tiger bee flies lay fertilized eggs near carpenter bee nests, typically in small cracks or crevices.

The hatched larvae then enter the carpenter bee nest and consume the carpenter bee larvae.

• Carpenter bee: A large, solitary bee species
• Tiger bee fly: A parasitic fly that targets carpenter bees

Feeding Habits

The primary food source for tiger bee fly larvae is carpenter bee larvae.

While carpenter bees are part of the class Insecta, phylum Arthropoda, kingdom Animalia, and as adults feed on nectar and pollen from flowers, their larvae serve as a food source for other species like the tiger bee fly larvae.

Example:

• A female tiger bee fly lays eggs near a carpenter bee nest.
• After hatching, a tiger bee fly larva enters the nest.
• The tiger bee fly larva consumes the carpenter bee larva.

Entity	Carpenter Bee	Tiger Bee Fly
Class	Insecta	Insecta
Phylum	Arthropoda	Arthropoda
Kingdom	Animalia	Animalia
Primary Food	Nectar and pollen (adults)	Carpenter bee larvae (as larvae)
Nesting Habitat	Wooden structures, tunnel through wood to make nests	Lays eggs near carpenter bee nests, larvae enter nest

Relationship with Humans and Other Animals

Pollination

Tiger bee flies (Xenox tigrinus) are members of the bombyliidae family and belong to the order Diptera, sharing similarities with other flying insects such as mosquitoes.

Although they are not considered major pollinators, some bee-flies play a role in the pollination of certain plants, like primroses.

These insects use their long proboscis to feed on nectar, inadvertently transferring pollen between flowers in the process.

Predators and Prey

Tiger bee flies are parasitoid insects, mainly preying on the larvae of carpenter bees.

In their search for food, they hover around wooden structures in yards, such as fences and roof overhangs, where carpenter bee larvae may be present.

• Prey: carpenter bee larvae
• Predators: spiders, mites, or other land invertebrates

These bee-flies face threats from various predators, including spiders and mites, which may be found among different types of arthropods with jointed legs, such as millipedes, centipedes, crayfish, and shrimp. Earthworms, slugs, and snails may also prey on the insects.

Despite their name, tiger bee flies do not bite or sting humans, posing no risk to people who encounter them.

While their wing markings and abdomen may resemble a bee, they are not aggressive and tend to be more focused on finding food and mates rather than interacting with humans.

Identifying Features and Differences

Tiger Bee Fly vs. Carpenter Bee

Tiger bee flies and carpenter bees have some distinct features. The main differences between them are:

• Size: Tiger bee flies are smaller, with a length of about 12-18 mm, while carpenter bees can reach up to 25 mm.
• Appearance: Tiger bee flies have transparent wings with large, white spots and tiger stripes pattern, whereas carpenter bees have a black body with some yellow fuzz.
• Habitat: Tiger bee flies are often found hovering around wooden privacy fences, wooden roof overhangs, and similar wooden surfaces. Carpenter bees, on the other hand, primarily nest in wood.
• Behavior: Tiger bee flies are parasites that lay their eggs in carpenter bee larvae nests, while carpenter bees are pollinators and rarely sting.

Feature	Tiger Bee Fly	Carpenter Bee
Size	12-18 mm	Up to 25 mm
Wings	Transparent with large, white spots	Solid, dark-colored
Body	Spotted, tiger stripes pattern	Black with some yellow fuzz
Habitat	Wooden surfaces	Nests in wood

Tiger Bee Fly vs. Bumble Bee

Tiger bee flies can also be confused with bumblebees due to their fuzzy, hairy bodies. The primary differences include:

• Size: Tiger bee flies are generally smaller, measuring 12-18 mm in length, while bumblebees range from 15-25 mm.
• Color: Tiger bee flies have black bodies with distinctive tiger stripes pattern, while bumblebees have black and yellow bands on their body.
• Wings: The wings of tiger bee flies are transparent and have large, white spots, contrasting bumblebees’ solid-colored wings.

Feature	Tiger Bee Fly	Bumble Bee
Size	12-18 mm	15-25 mm
Body	Black with distinctive tiger stripes pattern	Black and yellow bands
Wings	Transparent with large, white spots	Solid-colored

In summary, knowing the identifying features and differences between tiger bee flies, carpenter bees, and bumblebees will help in distinguishing them and understanding their behaviors and interactions.

Do Tiger Bee Flies Bite?

Tiger bee flies are known for their distinct appearance and unique behavior, often seen hovering near wooden structures.

These insects are part of the bee fly family, but their true nature may surprise you. Tiger bee flies (Xylocopa sp.) are parasites of carpenter bee larvae.

Despite their intimidating appearance and relation to bees, there’s no cause for alarm. Let’s explore why you don’t need to worry about tiger bee fly bites.

Their primary focus is on reproducing and parasitizing carpenter bees rather than interacting with humans or animals.

Due to this behavior, tiger bee flies do not pose any direct threat or harm to people.

Feature	Tiger Bee Fly	Carpenter Bee
Biting or stinging	No	Yes (for female)
Parasitic to larvae	Yes	No
Role in pollination	No	Yes

Conclusion

Tiger bee flies, often found around wooden structures, are known for their parasitic relationship with carpenter bee larvae. Despite their intimidating appearance, these insects do not bite or sting humans.

Their mouthparts aren’t designed for biting, making them harmless to people. Key features of the tiger bee fly include distinctive wing markings and a resemblance to bumble bees.

They are prevalent throughout North America, especially near wooden surfaces. Their life cycle involves laying eggs near carpenter bee nests, with the hatched larvae consuming the carpenter bee larvae.

Understanding their behavior and distinguishing them from other insects is essential for appreciating their role in the ecosystem.

Reader Emails

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 – Tiger Bee Fly

Strange Fly 3/4″ long in Simi Valley, CA
Hi Bugman!
My husband and I are real fans of your site. We find it exceptionally user-friendly, and seeing multiple images of an insect really helps with identification.

This fly-thingie landed on a palm tree next to my head and did not budge for fifteen minutes while I photographed it, tried to find it on your web site, and then finally went out and caught it.

It is currently laying on its back in my insect magnifying jar. Could it be a tachinid fly? Its wings are clear with black markings. Very truly yours,
Renee Fraser

Hi Renee,
Thanks for the compliment. We also noticed from your second email that you correctly identified your Tiger Bee Fly, Xenox tigrinus.

Letter 2 – Tiger Bee Fly

Subject: guarding my house today
Location: Oshawa, Ontario
August 12, 2015 1:57 pm
Dearest bugman,
Thanks to you, I have become more of a friend to bugs.
This afternoon, there is a very giant fly with spotted wings guarding the back door to my house. She (I think it’s a she) is sitting right on the keyhole!

Thankfully, I come in through the garage…I have a feeling it is a kind of horse fly but have never actually seen one. I’ve never seen a fly this big or one with markings on its wings. We are in Oshawa, Ontario and the day is sunny and windy but she would be out of the sun and wind where she is sitting right now.

Didn’t even care that I took pictures and opened the door twice…I was hoping to see a luna moth one day and not so much this guy…
be well and keep up the awesome work!
Signature: Robin

Dear Robin,
Thank you so much for your kind compliments.  This distinctive fly is a Tiger Bee Fly, a species that parasitizes Carpenter Bees.  Unlike female Horse Flies that might bite humans, this Tiger Bee Fly poses no threat to you or your pets.

Dearest Daniel,
Thank you so much for your response and for enlightening me about my visitor. I am honoured to be hearing from the bugman himself! I actually have your book!
Passion is what makes life worth living and yours is obvious.

To give of yourself and your time as you have for so many years is a most incredible testament to passion. Thank you for sharing that as you have and for teaching so many of us so very much.
Stay passionate,
Robin
ps – bibitte is the French word for bug – I’ve been driving a vw bug for 15 years…

I’m blushing.

Letter 3 – Tiger Bee Fly

Subject: What is this a deerfly?
Location: Hampshire, Illinois
July 25, 2016 3:17 pm
Hello, Bugmam!
I live in Hampshire Illinois, this guy showed up on my deck, I thought it was a moth and approached it flew at me, and wouldn’t stop I had to run ….literally …run into the house.
Can you tell me what it is called, besides what I called it…lol
I think it is some type of Deerfly. I may be wrong.
Signature: Gerardine Baugh

Dear Gerardine,
This is a Tiger Bee Fly and it neither bites nor stings, nor does it have venom or poison, so it is perfectly harmless, but that it not to say it cannot hurt you.  Imagine, if you will, if while you were running away from this harmless creature you tripped and fell and broke your leg. 

Though we don’t know why this harmless Tiger Bee Fly flew at you, there was really no harm it could have done had it landed on you.  According to BugGuide, the Tiger Bee Fly “is a parasitoid of Carpenter Bees, Xylocopa.”

Dear Daniel,
Thank you for this information. When I see it again I will take more pictures, and watch to see what it is up to.
Gerardine

Letter 4 – Tiger Bee Fly

Subject: Large black flying insect
Location: Columbus, Ohio
July 16, 2017 12:08 pm
We are seeing quite a few of these bugs in our backyard and one of our dogs is extra curious. Is it harmful or invasive? What is it?
Signature: Kate

Dear Kate,
The Tiger Bee Fly is native and it is harmless.

Letter 5 – Tiger Bee Fly

Subject:  Deer fly?
Geographic location of the bug:  Southern Ontario
Date: 09/10/2017
Time: 03:22 PM EDT
Father says it’s a deer fly but to me it seems to be to big.. any help? It’s 1/2″-1″ across. For scale the fly is on the side of a 2×4. Early September, middle of the day.
How you want your letter signed:  Wayne

Dear Wayne,
this is a Tiger Bee Fly, and you can verify its identity on BugGuide.  Tiger Bee Flies do not sting nor do they bite humans.

Letter 6 – Tiger Bee Fly

Subject:  Large fly
Geographic location of the bug:  Ontario, Can.
Date: 09/23/2017
Time: 03:56 PM EDT
Too hot to fly? Feels like 100F here today.
How you want your letter signed:  Del

Dear Del,
This is a Tiger Bee Fly, a harmless pollinator.

Letter 7 – Tiger Bee Fly

Subject:  Large Fly of some sort
Geographic location of the bug:  London, Ontario Canada
Date: 07/25/2018
Time: 06:55 PM EDT
Your letter to the bugman:  This thing has been visiting my workplace over the last few days. It’s fairly large and has basically no fear of humans. I’m guessing it could take a chunk out of me if it chose to but thankfully it hasn’t come to that. What exactly is it?
How you want your letter signed:  Mike Woodford

Dear Mike,
You have nothing to fear from this Tiger Bee Fly.  According to BugGuide:  “Adult food unknown. An adult has been observed on damp mud, lapping up fluids.”

Letter 8 – Tiger Bee Fly

Subject:  Large black flying insect with speckled wings
Geographic location of the bug:  Brooklyn, NY
Date: 08/05/2018
Time: 02:47 PM EDT
Your letter to the bugman:  Hey Bugman!
I was about to make some coffee when I heard a deep buzzing above me and looked up to find a rather large black flying insect (fly? wasp?) circling by the window trying to escape.

It’s got a black body about 3/4 of an inch long with black and clear speckled wings that extend out another centimeter or so. The only identifying marks I could see are symmetrical white spots on the last couple tergites.

I wanted to help it escape, but I have no idea if it stings or bites and didn’t want to risk it.
Thank you so much!!
How you want your letter signed:  Slightly Scared and Decaffeinated

Dear Slightly Scared and Decaffeinated,
The Tiger Bee Fly is not dangerous to humans.

Letter 9 – Tiger Bee Fly

Subject:  Is this a fly or a month?
Geographic location of the bug:  Southbridge, MA
Date: 08/06/2018
Time: 08:52 PM EDT
Your letter to the bugman:  Hello! This fascinating creature was sitting on the lockplate of my storm door for most of the day. Can you tell me what it is? Thank you! 🙂
How you want your letter signed:  Sue Rosner

Dear Sue,
This is the fourth image we are posting of Tiger Bee Flies, Xenox tigrinus, submitted to our site in the last week and a half.  It does not sting nor bite.  According to BugGuide:  “Larva is a parasitoid of Carpenter Bees, Xylocopa.”

Daniel –
Thanks so much! I do rent an apartment in a very old home in Southbridge, MA. The shed on the property is inundated with Carpenter Bees, so this makes total sense.
Best Regards,
Susan

Letter 10 – Tiger Bee Fly

Subject:  Butterfly? Day moth?
Geographic location of the bug:  North Alabama
Date: 07/08/2019
Time: 01:34 PM EDT
Your letter to the bugman:  This little creature was hanging out where our ladder attaches to the pool. Can you identify?
How you want your letter signed:  Tammy

Dear Tammy,
This is neither a butterfly nor a diurnal moth.  It is a Tiger Bee Fly, a harmless and very distinctive looking Fly.  See BugGuide for a comparison image.

Thank you so much for your time! I asked everyone around here if they knew what this interesting little creature that seems to have Zeus’s face on it’s back.
Best Regards,
Tammy

Letter 11 – Tiger Bee Fly

Subject:  Large fly
Geographic location of the bug:  Lincoln, MA
Date: 08/24/2019
Time: 11:33 AM EDT
Your letter to the bugman:  Hi Bugman,
This large fly (about an inch long) has been hanging around my deck for a few weeks. 

It has an unusual habit of repeatedly darting at the railing when it hovers near the wood.  I am usually able to identify insects on-line, but have not had luck with this one.
How you want your letter signed:  Inconsistent naturalist

Dear Inconsistent naturalist,
This is a Tiger Bee Fly and we get numerous identification requests for them each summer.  The female Tiger Bee Fly lays her eggs in the nest of Carpenter Bees, which might be the reason this individual is hovering year your wooden railing.  We love your action image.

Letter 12 – Tiger Bee Fly

Subject:  Tiger Bee Fly
Geographic location of the bug:  BuTyler Pennsylvania  (Butler???)
Date: 08/24/2019
Time: 08:58 AM EDT
Your letter to the bugman:  Is it normal to see a tiger bee fly in north western pennsylvania?  I have never seen one before
How you want your letter signed:  Rob Och

Dear Rob,
We suspect your sighting was in Butler, Pennsylvania, not BuTyler.  According to BugGuide data, the Tiger Bee Fly ranges over most of eastern North America, including BuTyler, Pennsylvania.

Letter 13 – Tiger Bee Fly

Subject:  Large Fly?
Geographic location of the bug:  Gaithersburg, Maryland, USA
Date: 07/19/2021
Time: 02:56 PM EDT
Your letter to the bugman:  This fly(?) has been flying around my deck.  He is about 1″ long.  He seems to like sitting on this light colored umbrella, but he does land on darker surfaces.
How you want your letter signed :  NancyA

Dear NancyA,
This impressive fly is a Tiger Bee Fly, a parasitoid that preys on Carpenter Bees.  According to the Missouri Department of Conservation:  “The female tiger bee fly deposits her eggs in places where carpenter bees have laid their eggs. The bee fly larvae eat the carpenter bee larvae.”

Thanks!  I thought I had not successfully submitted that email and photo, but
I guess I had!  I figured it out from a combination of searching the
WhatsThatBug web site and an Internet search and I was astounded to find out
what it is. 

I definitely have carpenter bees.  In fact, one is giving me
trouble in the very table that the umbrella is stuck in that the fly was
sitting on when I took the photo!
Nancy Anthracite