Underwing Moth: All You Need to Know – Quick Guide

Underwing moths are fascinating creatures that can intrigue both amateur and professional entomologists alike. There is so much to learn and explore about these unique insects. In this article, we will dive into the world of underwing moths to discover what makes them stand out among other moths.

You might be surprised to discover that underwing moths (genus Catocala) are masters of camouflage. Their forewings are usually dull tan, brown, or gray in color with wavy patterns, which allow them to blend seamlessly with tree bark when at rest (\source). However, they have a hidden side. When disturbed, they reveal their brightly colored hindwings in shades of orange, red, yellow, or pink, with striking dark patterns. You may have come across some species, such as the darling underwing (Catocala cara), which has a wingspan of about 3 ½ inches and can be found in wooded areas during late summer (\source).

So, let’s unveil the captivating characteristics, features, and habits of underwing moths in this informative article. By the end, you will have gained a deeper appreciation and understanding of these enigmatic insects.

An Overview: Underwing Moth

Underwing moths belong to the Erebidae family and are part of the Genus Catocala. These moths display fascinating features that make them stand out from other moth species. In this section, you will learn about their classification, scientific name, and some unique qualities.

Unlike common moths, underwing moths have forewings with dull colors like tan, brown, or gray, helping them blend in with tree bark. Their hindwings, however, are quite vibrant, showcasing bright colors like red, orange, yellow, or pink. This hidden color serves as protection from potential predators. They reveal the flashy hindwings only when threatened, startling their foes and providing a chance for escape.

Some examples of underwing moths you may come across include the oldwife underwing (Catocala palaeogama), the beloved underwing (Catocala ilia), and the darling underwing (Catocala cara). Each species has its unique pattern and coloration on their hindwings (Missouri Department of Conservation).

Some of the characteristics and features of underwing moths include:

• Dull-colored forewings that resemble tree bark
• Brightly colored hindwings
• Ability to conceal their vibrant colors
• Startle response to ward off predators

Remember, whenever you observe an underwing moth, appreciate its unique adaptation strategies that have allowed it to survive and thrive in the wild. Pay attention to their striking beauty and the way they seamlessly blend into their surroundings.

Morphology and Identification

Wings

Underwing Moths have distinct wing patterns, which makes it easy for you to identify them. Their forewings are typically darker, with intricate patterns or stripes, while the hindwings showcase vibrant colors, such as red, orange, or yellow, often with contrasting black bands. Remember to look for these eye-catching patterns when observing these moths!

Body Features

When examining an Underwing Moth, pay attention to the details of its body. These moths have a few unique features:

• A horn-like structure on the head
• Long, color-coordinated antennae
• Furry legs that match the forewing colors

Keep an eye out for these particular characteristics when trying to identify an Underwing Moth.

Size and Lifespan

Underwing Moths vary in size, with an average wingspan ranging between 1.5 and 3 inches (3.8 to 7.6 cm). So, when observing them, take note of their size to ensure you’ve found the right moth. Their lifespan also differs, but on average, they live for about one month.

Now that you know the key morphology and identification features of Underwing Moths, you’ll be able to spot them with ease during your next nature walk or outdoor adventure.

Life Cycle

From Eggs to Caterpillars

Underwing moths start their life cycle as tiny eggs laid on tree leaves. If you observe carefully, you might find these eggs on tree branches or underneath leaves. Once the eggs hatch, they become caterpillars, also known as larvae, and their primary goal is to consume leaves as food. They will feed on different types of leaves to grow and develop properly. As they continue to eat and grow, they will shed their skin several times before reaching the next stage.

Pupal Stage

In this stage, the caterpillar finds a safe spot, typically in leaf litter or grass, where it can undergo metamorphosis. It then produces a silk cocoon to protect itself and enters the pupal stage. Inside the cocoon, the caterpillar’s body transforms into the adult moth form. This process is known as metamorphosis and can take a few weeks, depending on factors like temperature and humidity.

Adult Moths

Once the metamorphosis is complete, the adult underwing moth emerges from the cocoon. Adult moths have a unique pattern on their wings to help them camouflage with the surroundings. They only have a short lifespan, and one of their main purposes is to mate and reproduce during this time.

Mating and Reproduction

Adult male and female moths use chemical cues called pheromones to find each other during mating. The female moth will lay her eggs on suitable host plants after mating. These host plants provide the newly-hatched caterpillars with a convenient food source. The adult moths will die soon after reproducing, and the cycle continues with the next generation.

Infestation and Control

An infestation of underwing moths can be problematic for gardeners and farmers due to the voracious appetite of the caterpillars. Some methods for controlling infestations include:

• Regularly inspecting plants and manually removing caterpillars.
• Encouraging natural predators like bats by providing suitable habitats.
• Applying biological controls such as Bt (Bacillus thuringiensis), a bacterium toxic to caterpillars.

By understanding the life cycle of underwing moths and taking appropriate measures, you can help maintain the delicate balance between these fascinating creatures and your plants.

Habitat and Distribution

Natural Habitats

Underwing Moths inhabit various ecosystems such as deciduous forests and temperate forests in North America, Europe, and Asia. They particularly favor:

• Tree trunks
• Tree bark

These habitats offer camouflage, as their wing patterns often resemble tree bark, providing them protection from predators. Deciduous forests are abundant in tree species that support their survival and reproduction needs.

Geographical Spread

The geographical range of Underwing Moths is vast, spanning across:

• North America
• Europe
• Asia

In North America, they are prominently found in deciduous or mixed forests. In Europe, they inhabit temperate regions, while in Asia, their distribution can vary across diverse ecosystems.

Here’s a quick comparison table of the Underwing Moths’ distribution:

Keep in mind that although they have a wide geographical spread, their populations might face habitat loss or fragmentation due to human activities and climate change.

Diet and Feeding Habits

Plant Based Diet

Underwing Moths have a predominantly plant-based diet, feeding on various types of vegetation. In their caterpillar stage, they consume the leaves of deciduous trees such as willow and cherry. In addition, they also feed on the flowers of certain plants. As adult moths, their diet consists mainly of nectar from flowers.

Here are some common food plants for Underwing Moths:

• Willow
• Deciduous Trees
• Cherry
• Flowers

Role in the Ecosystem

These moths play a significant role in the ecosystem as both herbivores and a food source for natural predators. By consuming plant material, they aid in recycling nutrients back into the soil and support plant growth. Furthermore, their consumption of nectar helps to pollinate flowers, contributing to plant reproduction and biodiversity.

Natural Predators

Underwing Moths have a variety of natural predators that contribute to maintaining balance in the ecosystem. Some of their primary predators include:

• Bats
• Birds
• Spiders

During their caterpillar stage, they are more vulnerable to predation, so they often rely on their excellent camouflage to blend in with their surroundings and avoid detection from hunters. As an adult moth, they fly mainly at night, helping them evade predators and safely feed on nectar.

Famous Underwing Moth Species

The Darling Underwing

The Darling Underwing (Catocala cara) is a large, dark moth with a wingspan of about 3.5 inches. You can find this species in wooded areas, typically towards the end of August.

The Tearful Underwing

The Tearful Underwing (Catocala lacrymosa) is known for its striking appearance. This species has bold patterns and color combinations that help it blend in with its natural surroundings.

The Oldwife Underwing

The Oldwife Underwing (Catocala palaeogama) is another fascinating underwing moth species. It is characterized by its dull brown or gray forewings with wavy lines that mimic tree bark patterns. Its hindwings are bright and contrasting, which adds to its unique appearance.

The Beloved Underwing

The Beloved Underwing (Catocala ilia) is a species that is easy to spot, thanks to its bright orange or red hindwings with bold, dark patterns. This species is a great example of the vibrant colors and patterns that can be found among underwing moths.

The Red Underwing Moth

The Red Underwing Moth (Catocala nupta) is quite distinctive due to its bright red hindwings with a contrasting black pattern. This species is commonly found in Europe and displays varying patterns and colors depending on its population and habitat.

To sum up, these Underwing Moth species offer a glimpse into the diverse appearance and stunning colors of the Catocala genus. Each species has unique adaptations that help them blend in with their environment, while their vibrant hindwings provide a striking contrast when revealed.

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 – Echo Owlet Moth from South Africa

Subject: Moth from South Africa
Location: Cape Town, South Africa
February 18, 2015 12:45 pm
Hi there!
I hope you guys can help to identify this magnificent moth.
Spotted in a garden in Cape Town, South Africa in mid Feb.
Lots of granadilla and lavender plants around.
Never seen one even remotely similar – the photo is pretty good though, I hope we can identify it and find out more.
Please let me know what turns up!
Looking forward to your reply and thanks for the help!
Signature: Yours truly, NJV

Dear NJV,
Your lovely moth with its curled wings reminded us of an Australian Fruit Piercing Moth, so we searched the subfamily Catocalinae on iSpot and we quickly found the Echo Owlet Moth, Achaea echo, a perfect match for your moth.  The species is also pictured on African Moths.

Superb!!
Thank you so much for the help, I really appreciate it!
Have a fantastic day,
Kind Regards
Norman Visser

Letter 2 – Clouded Underwing, we believe

Subject:  Unidentified moth
Geographic location of the bug:  Carrboro NC
Date: 08/22/2019
Time: 04:59 PM EDT
Your letter to the bugman:  Hi all, love your website, and you always seem to find the answer! I found this rather bedraggled moth on a tree trunk. It was fairly large….like a Sphinx moth, but the head looks wrong for a Sphinx…and underwing of some sort? I couldn’t match it with any Sphinx that I knew.
How you want your letter signed:  Mothra

Dear Mothra,
We didn’t have high hopes for providing you with a species name, though we had confidence that this is an Underwing in the genus Catocala.  We believe this BugGuide image of a Clouded Underwing, Catocala nebulosa, looks like it might be correct.

Letter 3 – Moth from Nicaragua: Bewitching Melipotis

Subject:  Moth ID
Location:  San Juan Del Sur, Nicaragua
July 4, 2016
San Juan Del Sur nica
Taken by Kryss Castle in Nicaragua.
Allison Jones

Dear Allison,
We first located a matching image to Kryss’ Moth on The Moth Photographers Group where it is identified as Melipotis fasciolaris.  We cross checked that name on BugGuide and found this image of the male.  We learned on BugGuide that this species is sexually dimorphic, meaning males and females look like different species, and that is has the common name Bewitching Melipotis.  It ranges from the Southern US to Uruguay.

Letter 4 – Mount Washington Walnut Underwing sighting

Walnut Underwing Visits WTB?
Location:  Mount Washington, Los Angeles, California
March 30, 2015 7:00 AM
Each year we get visits from Walnut Underwings, and it is always a very exciting sighting, though our native Noctuoid is considerably smaller and less colorful than the numerous Saturniids that are currently being submitted to our site.

Letter 5 – Possibly Penitent Underwing

type of underwing moth?
Hi again:
I keep finding amazing moths in our yard in central North Carolina (near Chapel Hill). Is this a type of underwing moth? That’s the closest I came on your website, but I didn’t see one with this coloring and pattern. The pattern on the wings is sort of a metallic blue and purple and the pattern looks like a bat head. What do you think?
Sandy

Hi Sandy,
This is an Underwing Moth and it might be a Penitent Underwing, Catocala piatrix. We found a nearly exact match on BugGuide.

Letter 6 – Walnut Underwing Moth in Los Angeles

July 17, 2010
We were sitting on the front porch when we saw this Underwing Moth in the genus Catocala alight on the carob tree during the afternoon.  We are uncertain what species it is.  There are many possibilities picture on BugGuide, many of which look the same to our untrained eyes.  Exactly one year ago, we posted an image of an Underwing Moth that was attracted to the porch light.

Update:  September 12, 2013
Through the years, we continue to see Underwing Moths, nearly every summer, and we now believe this is a Walnut Underwing, Catocala piatrix, which Charles Hogue writes about in Insects of the Los Angeles Basin, indicating:  “On the hottest days of summer (in July and August) adults may been seen [sic] flying during the day in the neighborhood of the larval food plant, which is the California Walnut (Juglans californica).”  BugGuide calls this species the Penitent.

Letter 7 – Moth from India

help with the ID please
Location:  Nagpur City,Maharashtra State,India
August 14, 2010 4:41 am
Hi again.
WTB has helpd me to start observing the beauties of nature again.so whenever i come across something that catches my eye i click it.used to do it earlier but kinda lost touch.thanks to WTB that i felt like starting with it again.
yesterday i came across this pretty moth.need your help with the identification.does it belong to the Catocala family?
thanks a lot.
Abhishek Sagar

Hi Abhishek,
We need to do some research on this moth, but we do not believe it is in the genus Catocala, but it may be in the family Erebidae that includes Catocala, or possibly in the Owlet Moth family Noctuidae.  At any rate, we do believe it can be classified in the superfamily Noctuoidea which includes both Erebidae and Noctuidae.  We will post your letter and photo and request assistance from our readership.

Karl provides another identification
August 15, 2010
Hi Daniel and Abhishek:
I am fairly certain that the genus is Dysgonia (Noctuidae: Catocalinae) but there are a number of species in India and many of them look similar. D. stuposa looks like a close match and it ranges though much of Asia (India to Japan and Indonesia). Regards. Karl.

Letter 8 – Walnut Underwing makes seasonal appearance in Mount Washington

Subject:  Walnut Underwing
Location:  Mount Washington, Los Angeles, California
Date:  June 27, 2014
Most every year, we get at least one visit from a Walnut Underwing, and since the endangered California Black Walnut Trees in the yard are growing nicely, we hope we will see an increase in the moth population.  About a week ago, a tattered individual was on the porch light and for the past several days, this beauty has been seen at night and is generally on the screen door the next morning.  Last night, a huge commotion in the kitchen turned out to be our feisty feline Boris trying to catch this Walnut Underwing which was on the other side of the glass window.  Thought it landed with its underwings visible, it flew before we could get the camera.  These dorsal and ventral (somewhat showing the patterns on the underwings) views will have to suffice for now.

Letter 9 – Walnut Underwing pays annual visit to WTB?

Subject:  Walnut Underwing Perch
Geographic location of the bug:  Mount Washington, California
Date: 08/16/2019
Time: 11:03 AM EDT
Your letter to the bugman:  Dearest Bugman,
It was lovely spending time with you during the almost full moon. Please enjoy this shot of you with a Walnut Underwing on your shoulder.
How you want your letter signed:  Melanie on the Irish Chain

Dear Melanie,
We are so happy you were able to get a cellular telephone image of Daniel as he removed the Walnut Underwing back to the outdoors after it entered the house Monday night.  After several minutes of eluding capture, luckily the moth alighted on Daniel’s shirt, and it could easily be walked outside.

Letter 10 – Walnut Underwing visits the offices of What’s That Bug?

Subject:  Walnut Underwing visits WTB?
Location:  Mount Washington, Los Angeles, California
July 26, 2015 9:29 PM
We never tire of visits from Walnut Underwings, and we have had more sightings this year than we can ever remember in a season.  We finally got a peep at those brightly colored underwings that give this Noctuoid its common name.

Letter 11 – Walnut Underwing visits WTB? Office

Subject:  Walnut Underwing
Location:  Mount Washington, Los Angeles, California
May 17, 2016 6:48 PM
Each year we look forward to the first appearance of a Walnut Underwing at our office.  We were pleasantly surprised by this especially gorgeous individual earlier in the week.  Perhaps we will try to get a good image with the colorful underwings revealed the next time it comes to the porch light.

Letter 12 – White Underwing

Mystery Moth
Dear Bugman,
Love your site! My boys and I are having so much fun identifying the different critters we come across in our yard. This unfortunate creature was removed from the grill of our car. We don’t come across too many moths this size in our area, so at first I thought it could be some sort of sphinx, I’m not sure that’s right though. We live in a heavily wooded area in southwest WA. What is it? Thanks,
Heidi

Hi Heidi,
Some specimens of Catocala relicta have nearly white forewings, giving rise to the common name White Underwing. Your specimen has gray forewings, which makes the common name White Underwing seem odd. BugGuide shows specimens with a wide range of forewing tonalities.