American Hornet Moth: Essential Facts and Tips

The American Hornet Moth is a fascinating species that resembles a stinging wasp but is, in fact, a harmless moth.

This clever mimicry helps it avoid predators, as many are hesitant to attack something that looks like a dangerous hornet.

Native to North America, the American Hornet Moth belongs to the family of clearwing moths.

These moths have a unique appearance, with partially transparent wings and vivid patterns that imitate wasps or bees.

Their striking looks are not just for show; they also serve a vital purpose in the survival of the species by deterring potential threats.

In this article, we’ll dive into everything you need to know about this remarkable insect.

Overview of the Hornet Moth

The American Hornet Moth (Sesia tibialis) is a species of clearwing moth belonging to the family Sesiidae within the order Lepidoptera.

Sesiidae, also known as clearwing moths or wasp moths, consists of more than 1,000 species globally. These moths have:

• Transparent wings, resembling wasps or bees
• Narrow, elongated bodies
• Restricted proboscises for feeding on specific flowers

Other notable species in the Sesiidae family include the Lunar Hornet Moth (Sphinx apiformis) and Poplar Clearwing Borer (Sphinx tenebrioniformis).

American Hornet Moth Vs. Other Species

The American Hornet Moth differs from other species like the Lunar Hornet Moth and Poplar Clearwing Borer in the following ways:

The American Hornet Moth is primarily found in North America, where it serves as a pollinator for native plants.

It has a preference for cottonwood trees (Populus spp.) and acts as the Cottonwood Crown Borer.

In comparison, the Lunar Hornet Moth is native to Europe and prefers sallow trees (Salix spp.), while the Poplar Clearwing Borer, also found in Europe and Asia, feeds on poplar trees (Populus spp.).

The larvae of these moth species have distinct feeding behaviors: the American Hornet Moth girdles tree stems, the Lunar Hornet Moth bores into tree trunks, and the Poplar Clearwing Borer creates tunnels within the tree trunks.

Their antennae also vary, with the American Hornet Moth having distal segments being more rigid compared to proximal segments, while both the Lunar Hornet Moth and Poplar Clearwing Borer have uniformly rigid segments in their antennae.

Life Cycle and Reproduction

Eggs

The American Hornet Moth (Sesia tibiale) is found across North America, including the United States and Canada.

This moth’s life cycle begins with the female moth laying her eggs. The eggs are typically laid during late spring or early summer, particularly around April to August.

The eggs tend to be deposited on the bark of host trees, such as aspens, poplars, and cottonwoods, which are commonly found near pond edges.

Larvae and Pupae

• Larval stage: Once the eggs hatch, the larvae tunnel into the wood of these trees. The larval stage lasts roughly a year, when they feed on the wood, causing potential damage to the trees.
• Pupal stage: After the larval stage, the larvae will then pupate within the wood. Eventually, they will form a cocoon and undergo metamorphosis within the soil near the base of the host tree. The pupal stage typically spans from April to September, depending on environmental factors such as temperature and availability of host trees.

Adult Moths

• Appearance: Adult American Hornet Moths display remarkable mimicry, closely resembling black and yellow wasps. This clever camouflage helps protect them from predators.
• Mating: The female moth emits pheromones to attract the male moth for mating. Once the male detects the female’s scent, they will mate, and the cycle starts anew.

Comparison between American Hornet Moth and Wasps

The American Hornet Moth is an interesting species with a unique life cycle and remarkable wasp-like appearance, which helps it survive and thrive in various habitats across North America.

Physical Characteristics

The American Hornet Moth (Sesia tibialis) belongs to the clearwing moth family. Key features include:

• Size: Approximately 1.5 – 2 inches wingspan
• Wings: Clear wings with dark borders
• Abdomen: Black and orange/yellow striped

This moth is often mistaken for a hornet due to its similar size and coloration.

Mimicry

The American Hornet Moth is known for its Batesian mimicry – this means it has evolved to resemble a more dangerous species, in this case, a hornet.

This form of mimicry helps deter predators from attacking the moth. Some differences between the American Hornet Moth and a hornet are:

When identifying the American Hornet Moth, look for its clear wings, distinct coloration, and mimicry of hornets. Recognizing these features can help distinguish it from the actual hornet and other clearwing moths.

Distribution and Habitat

North American Range

The American Hornet Moth can be found in various regions across North America, such as:

• British Columbia
• Colorado
• Michigan
• Washington
• California

This moth prefers areas with abundant vegetation and can be frequently seen in:

• Parks
• Golf courses
• Fens

Habitat Preferences

The American Hornet Moth is quite adaptable and can thrive in diverse environments, from the arid landscapes of Colorado to the lush greenery of Washington forests.

Some key habitat preferences include:

• Proximity to water sources
• Areas with ample vegetation
• Availability of host plants for larvae, such as willows and poplars

Comparison table of habitat preferences in various regions:

The American Hornet Moth’s adaptability makes it a fascinating species, able to successfully occupy different habitats within North America.

Ecology and Impact

The American Hornet Moth is a wood-boring insect that can cause damage to several tree species. As a pest, it primarily targets:

• Poplar trees
• Willow trees
• Cottonwood trees

Larvae of the American Hornet Moth create tunnels within the wood and stem of these trees, weakening their structure and making them susceptible to other diseases and pests.

Predators

The American Hornet Moth has a few natural predators, including:

• Birds
• Spiders
• Parasitic wasps

These predators help control the population of American Hornet Moths in their environment.

Lifespan and Overwintering

The American Hornet Moth has a relatively short lifespan. Its larvae overwinter within the wood of their host trees, and emerge as adult moths in late spring or early summer.

Adult moths only live for 4- 10 days, during which they mate and lay eggs on suitable host trees.

Comparison to Butterflies

The American Hornet Moth, while not a butterfly, shares some similarities with them. Both are part of the order Lepidoptera, and have some similar features such as:

• Wingscales
• Proboscis for feeding on nectar

However, there are also differences between the two groups:

By understanding the ecology and impact of the American Hornet Moth, researchers and tree care experts can develop strategies to manage and mitigate the damage caused by these pests.

Conclusion

The American Hornet Moth, a remarkable species of clearwing moth native to North America, showcases a clever mimicry of stinging wasps, aiding in its survival by deterring potential predators.

With its transparent wings and vivid patterns imitating wasps and bees, this moth fascinates researchers and nature enthusiasts alike. While it may be mistaken for a dangerous hornet, it is, in fact, harmless.

Readers’ Mail

Over the years, 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 – American Hornet Moth

Subject: Some type of wasp….
Location: Vancouver Washington area
August 17, 2017 3:13 pm
Hello! I would like to know the identification of this flying insect please? thanks!
Signature: Respondents choice. No preference.

Though it is not a Wasp, it is an effective wasp mimic as the common name of the American Hornet Moth implies, and we believe we have correctly identified your individual, though a higher resolution image would be helpful. 

According to BugGuide:  “In flight they closely resemble wasps, even producing the droning sound.”

Letter 2 – American Hornet Moth

Subject:  Wasp w/hornet like coloring and long curled antennae
Geographic location of the bug:  Portland OR
Date: 07/27/2018
Time: 06:59 PM EDT
Your letter to the bugman:  Hello,
Found this guy chilling on the shaded wall of a building, so still I thought he may have been asleep. 90+ F outside, so maybe he/she was just lethargic.

We are in an industrial area of town near slow-moving swampy backwaters of the Columbia River, so it is a very entomologically active place. Spider wasp maybe? But so brightly colored!
How you want your letter signed:  Thanks, Hayley

Dear Hayley,
This is neither a wasp nor a hornet.  It is a Clearwing Moth in the family Sesiidae, a group with many species that are effective mimics of stinging insects.  We have identified your moth on BugGuide as the American Hornet Moth, Sesia tibiale, and according to BugGuide, other common names include Poplar Clearwing Borer and Cottonwood Crown Borer.

Letter 3 – American Hornet Moth

Subject:  Wasp-like bug in the Rockies
Geographic location of the bug:  British Colombia, Canada – in the mountains
Date: 09/07/2018
Time: 01:30 AM EDT
Your letter to the bugman:  I found this wasp-like bug at Panorama, BC. Its tiny head and almost moth-like antenna made me stop and look again. I wish I knew what it was. It did not move while I studied it, but I also did not want to disturb it as I don’t know if that’s a real stinger or if its a copy-cat! I saw it the second week of August.
How you want your letter signed:  Nicole

Dear Nicole,
Your observations are quite astute.  Though it resembles a wasp, the American Hornet Moth, Sesia tibiale, which is pictured on BugGuide, is a member of the Clearwing Moth family Sesiidae, a group that contains many members that mimic stinging insects. 

According to BugGuide:  “In flight they closely resemble wasps, even producing the droning sound. ”  The species is also known as the Poplar Clearwing Borer or the Cottonwood Crown Borer.

Letter 4 – American Hornet Moth

Subject:  Please Identify
Geographic location of the bug:  Western Oregon, Outside Eugene
Date: 03/11/2019
Time: 11:43 PM EDT
Your letter to the bugman:  I found this beauty while visiting a local lake in 2017.  It didn’t attempt to fly away the entire time we were there, and seemed unfazed when I stuck a phone camera several inches from its face. 

 I was afraid it was dead, but it was still moving a bit.  Thank you!
How you want your letter signed:  Dan

Dear Dan,
This is one of the Clearwing Moths in the family Sesiidae, a group that includes many members that mimic stinging wasps and bees for protection.  Your individual is an American Hornet Moth, Sesia tibiale, which we identified on BugGuide, and according to BugGuide:  “In flight they closely resemble wasps, even producing the droning sound.”

Letter 5 – Hornet (Vespa velutina) captures Caterpillar

What are these 2 bugs?
BugMan,
Can you please tell the full name of the green & black bugs? Thanks
Leon

Hi Leon,
In the most general sense, this is a Hornet capturing a Caterpillar. Since you did not provide global coordinates, identification to the species level is not assured. The Hornet might be Vespa crabro, the European Hornet which was introduced to the eastern U.S. and is common locally in some areas, including Pennsylvania.

The caterpillar is quite generic, possibly in the Pieridae. Adult Hornets are generally nectar feeders, but they are social creatures and will capture Caterpillars and other insects. They will then chew them and regurgitate them for the larval hornets in the nest. Eric Eaton corrected us by writing in: “The hornet is indeed a Vespa species, just not V. crabro.”

Hi, Thank you at first. And the pic was took in Guangzhou, China. Guangzhou is near the Hongkong. May be it is a suprise to you, 🙂 I got knowing your website from the Click(Webscrape) progam of BBC world.
Leon

Letter 6 – Hornet Moth

Subject: Bees Wasps
Location: Soham Cambridgeshire UK
May 3, 2013 3:47 pm
Dear Sir.
I saw this bug on a tree in Soham Cambridgeshire UK almost a year ago.
I have had no way of uploading the picture till now as not had a computer.
It was a lovely sunny day in June of last year 2012.
It is about an inch in length, with a blue band around it;s’ middle. I have
never seen one of these before and was wondering if it is a rare species to this country
or it may have got lost on its travels. I didn’t notice any stinger on it.
If you could help I would be most appreciated.
Signature: Nick Halliday

Dear Nick,
This clever little mimic could fool most folks.  This is not a bee nor a wasp.  It is a Hornet Moth, Sesia apiformis, a moth that mimics a stinging hornet as a means of protective coloration.  According to UK Moths:  “Rather similar to the Lunar Hornet Moth, this species can easily be distinguished by the yellow head and tegulae.  It has a more southerly distribution than that species, rarely being encountered north of the Midlands. 

The larvae burrow into the wood of black poplar (Populus nigra), and other species of poplar.  The moths emerge in June and July, and can be found low down on the trunks in early to mid morning.”  The Hornet Moth is in the family Sesiidae, the Clearwings, which includes many species with similar protective coloration and markings.

Letter 7 – Pleasant Hornet Moth from South Africa

Please help to ID this insect
Greetings!
I came across this moth-like insect in Chintsa East, a coastal village in South Africa’s Eastern Cape province during March this year (late summer/early autumn). It looks a little like the American oleander moth, but is obviously not the same thing.

Someone suggested it might be a Euchromia Formosa , but the pictures I’ve seen of those look a little different, especially in the number of red bands. Any idea what this is? Regards,
Iain Scott

Hi Iain,
The suggestion you provided for us, Euchromia formosa, though not correct, allowed us to quickly identify your moth. We searched other members of the genus in South Africa, and discovered the Pleasant Hornet Moth, Euchromia amoena. This group of moths are excellent wasp mimics.

Letter 8 – Pleasant Hornet Moth from South Africa

Subject:  Moth butterfly?
Geographic location of the bug:  Winklespruit
Date: 01/05/2018
Time: 11:53 AM EDT
I spotted about 20 of these on a lawn. Some of them were mating and the rest were very lethargic
How you want your letter signed:  Trish

Dear Trish,
First we must congratulate you on recognizing that though it resembles a hornet or wasp, this is actually a moth.  We believe, thanks to Blue Gnu, that is is a Pleasant Hornet Moth, Euchromia amoena, and the site states:  “The Pleasant Hornet is actually a form of moth that flies in the day. 

It is a beautiful insect that will be found congregating on plants that have a lot of pollen. It tends to favour whitish flowers.  The preferred habitat of the Pleasant Hornet is subtropical forests and bushveld near to the coast.” 

We have a similar look, but differently marked individual on our site already identified as Euchromia amoena, so we acknowledge that one might be incorrect, or there might be individual color variation, but we are confident that both postings are the same genus.

Letter 9 – Splendrous Hornet Moth from South Africa

Subject: Unknown bug
Location: Richards Bay KZN SA
February 27, 2014 6:50 am
HI
I took this image or a few from my garden in Richards Bay, KZN, SA. It was sucking nectar on a bush known to draw butterflies. Could you possibly identify it?
Signature: Pauline Hibbert

Dear Pauline,
This is either a Splendrous Hornet Moth, Euchromia formosa, or a closely related species in the same genus.  You can compare your excellent image to the one on Encyclopaedia Britannica or the ones on ISpot.

Letter 10 – Arctiid Moth from South Africa is Splendrous Hornet Moth

Subject: Iridescent flying insect in South Africa
Location: Port Shepstone, +-100 km South of Durban, South Africa
February 20, 2013 4:20 am
Hi there – my mom who lives on the east coast of South Africa (Port Shepstone) took this shot of a lovely iridescent insect in her garden. Is it a type of colourful moth perhaps?
Wonderful site by the way 🙂
Signature: Cat Robinson

Dear Cat,
This is one of the Tiger Moths in the subfamily Arctiinae, but our quick search did not turn up a species match.  Many moths in this group mimic wasps.  We will contact Tiger Moth specialist Julian Donahue to see if he can provide a species identification.

Julian Donahue provides an identifidation:  Euchromia amoena
This appears to be an excellent match for Euchromia amoena (Möschler, 1872), apparently widespread in southern Africa.
“Amoena” is from the Latin, meaning “pleasant” or “delightful,” so you can coin your own common name if you’re unable to find one already in use.
Julian

Thanks Julian,
There is a matching image on Encyclopedia of Life.

Thank you so much for this! You are really providing a wonderful service – greatly appreciated J
Kind regards,
Cat Robinson

Update:  December 29, 2013
A recent comment indicates this may be another member of the genus:  Euchromia formosa, the Splendrous Hornet Moth, which is pictured on the Insect Collector’s  Shop.