Copper Underwing Caterpillar or Humped Green Fruitworm: Identification Guide

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In this article, we share information on the copper underwing caterpillar

Do you think of moths as boring, brown insects? Think again. Behind those boring brown wings, you might find bright colors like red and orange! 

Moreover, moths during their larval stage can be brightly colored caterpillars.

The case in point is the Copper Underwing Caterpillar or the Humped Green Fruitworm – a bright green caterpillar. 

 

Copper Underwing Caterpillar
Source: WanderingMogwaiCC BY-SA 4.0, via Wikimedia Commons

 

The copper underwing is part of a family of underwing caterpillars, like the large yellow underwing or pink underwing, who all grow into moths with brightly colored underwings.

For example, the Copper underwing caterpillars grow into brown moths that hide bright orange underwings that you only see when they are in flight. 

What Is a Copper Underwing Caterpillar? 

A Copper Underwing Caterpillar is the larval stage of the Copper Underwing moth. Their bodies are blue-green in color, segmented, and can reach a length of 1.10 inches

The moth caterpillar has a queer, pyramidal shape and distinct hump on its rear, through which you can easily identify them. 

There is also a thin line running along the back of their body. 

What Do Copper Underwing Caterpillars Turn Into?

After chrysalis, copper underwing caterpillars turn into brown-colored moths, simply called Copper Underwings. 

Despite its name, the moth actually belongs to the Amphipyrine Sallow family, not the Underwing family. 

 

Copper Underwing Caterpillar
Source: Beatriz Moisset, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons

 

What Does It Look Like?

Adult moths are dark brown in color. Their wings have specs of lighter shades, with a tan spot at the center of their forewings. 

The hindwings, which are hidden unless in bright light, are a bright, coppery color. 

Visually, it is very similar to other moths of the Underwing family. The latter has a thick dark band instead of specs. 

As a caterpillar, they’re blue-green in color with tiny specs of cream and yellow. 

There is also a yellowish ridge running atop their body with spots on them. The 8th abdominal segment has a raised hump. 

How Big Is a Copper Underwing Caterpillar and Moth? 

The copper underwing moth is larger in size than those belonging to the underwing family. Their wing span can go up to 2.3 inches

The caterpillar or Humped Green Fruitworm ranges in size from 0.9 to 1.1 inches

What Do Copper Underwing Caterpillars Eat?

This pyramidal Green Fruitworm is not at all fussy and can survive on a large range of broadleaf trees (they’re generalist feeders). 

Some common host plants are basswood, rhododendron, willow, oak, birch, and fruits of deciduous trees

Among vines, they feed on raspberry, grape, and Virginia creeper. They have a special affinity towards apples and can sometimes eat rosebuds. 

 

Copper Underwing Caterpillar

 

Lifecycle of A Copper Underwing Caterpillar

Adult copper underwings lay eggs on the leaves of deciduous trees. After winter, the eggs hatch into caterpillars that feed on leaves and fruits. 

During this time, they are common prey for birds. Around the end of June, the caterpillars turn into pupae. 

The pupae are dark brown in color. Adult moths emerge towards the end of summer. Currently, very little study has been done on their chrysalis. 

Adult moths are nocturnal and attracted to light. They are also attracted to sugar and sugary substances. You can identify female moths as they are larger in size than males. 

Do They Bite or Sting?

The green fruitworm attacks leaves and fruits. They are commonly kept as pets by children to observe the life cycle of a caterpillar. 

As such, there is no evidence of them biting, stinging, or posing any threat to humans. 

If your garden has an infestation, you can get rid of them by using natural insecticides or sparing water mixed with dish soap. 

 

Copper Underwing Caterpillar
Source: Donald Hobern from Canberra, AustraliaCC BY 2.0, via Wikimedia Commons

 

Are They Poisonous or Dangerous?

The bright orange color of the moth leads many to believe that these moths are poisonous. But it is not so. 

All caterpillars and moths belonging to the underwing family (or Noctuidae as the scientific name goes) are non-toxic for predators. 

Sometimes, the scales on some moth species can cause allergies

Do They Infest and Damage Crops?

Copper underwing caterpillars are feeders on leaves and fruits. They can leave round holes in your crops and destroy fruits. 

While they can cause damage and wastage, they are not typically considered pests. 

This is because they are univoltine or capable of only producing one generation per year. Unlike pests that infest and reproduce quickly, copper underwings are a slow-growing insect. 

What Eats Them?

Common predators of the caterpillar are birds, beetles, and wasps. Sometimes, wasps or other insects may lay parasitic eggs on their body so the larvae can feast on the caterpillar after birth. 

The caterpillars hide on the underside of the leaves. They do not have any special defense mechanisms, though the bright color of the moth deters some birds. 

Frequently Asked Questions

Where do copper butterflies live?

Copper underwings are found in the Palaearctic region. This includes the US, southern parts of Canada, North Africa, Korea, and Japan. 
They are quite widespread in this area but do not hang out in large groups. Their ideal habitat is woodlands, shrubbery, and open gardens. 

Is the red underwing moth rare?

The red underwing is a common moth found across multiple continents. In North America, they thrive in California and Arizona as well as in southern Canada. 
In Europe, they’re common in Central and Southern regions as well as England.

How long does a copper butterfly live?

The copper underwing moth has 1 generation every year. Being a larva takes up most of this time as butterflies tend to have a lifespan of a few weeks only. 
Copper butterflies, however, are a completely different species. The adult copper butterfly has a lifespan of only two weeks

What does the caterpillar change into?

The pyramidal green fruitworm eventually changes into a brown-colored moth. Caterpillars usually form pupas just before winter. 
Though sometimes pupae might appear as early as April, depending on the climate. Adult moths emerge around May or June.

Wrap Up 

Non-toxic caterpillars are a great way for kids to observe the life cycle of moths. The Humped Green Fruitworm is very easy to identify due to its unique look and color. 

You will find many of them concentrated in the same region – especially if you have apple trees growing. Thank you for reading!

 

 

 

 

 

Authors

  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

    View all posts
Tags: Underwing Caterpillars

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