The Salt marsh moth is also called Salt marsh tiger, Acrea moth, Tiger moth, and Acres moth. This moth lives in Canada and the US, and is considered a pest due to the larva’s ability to defoliate the host plants' leaves.
Salt marsh moth species summary
|Scientific Name||Estigmene acrea|
|Habitat||Thickets, woods, tidal or salt marshes, grasslands, farms|
|Range||Canada and the US|
|Host Plants||Potato, milkweed, dogbane, lettuce, corn, apple, cabbage|
|Moth Description||White forewings, orange hindwings, all filled with black dots|
|Caterpillar Description||Orange body with black fuzzy coat|
What color is the salt marsh moth?
The average wingspan of an adult Salt marsh moth ranges from 1.5 to 2.5 inches. Regardless of gender, the moths have 3 to 4 black blotches or markings sitting on their hindwings.
The head and thorax of the adult Salt marsh moth are white, while the abdomen and thorax are yellow-orange, with hints of black spots scattered throughout these areas. Their forewings are white and peppered with black markings, spots where solid black lines were once present.
On the other hand, their hindwings are darker shades of yellow-orange for adult males, while the females have a white base for both the abdomen and the hindwings. Some adult Salt marsh moths do not have spots in any parts of their bodies.
Larva Physical Description
Salt marsh larvae look like woolly worms with brown and yellow spots. They have black or orange-colored tubercles where the bristly hairs seem to emerge.
The hues of these body coverings may vary depending on many factors, such as subspecies and the environment they are in. These varieties include black, yellow, reddish-brown, and grayish-white.
The Salt marsh caterpillar can grow as long as 2 inches during its final instar. After this, it will transition to the pupal stage and spin its cocoon while attached to the host plant.
What is a salt marsh moth’s habitat?
The Salt marsh moths can be found in the following types of habitats:
- Tidal or salt marshes
- Farm fields
Usual Host Plants
The adult female Salt marsh moths lay their eggs on the following host plants:
- Plants from the milkweed or dogbane family
- Apple tree
What does the salt marsh moth eat?
While in caterpillar form, they feed on the host plants’ leaves. Adult moths don’t feed. This is partly because due to their reduced mouthparts and proboscis and partly because they already have fat stores that help them survive for a few weeks.
Behavior and effect on host plants
Salt marsh larvae have big appetites and are notorious for defoliating leaves, thus leaving a once-healthy leaf with just the pieces of its veins. As they get older, they tend to eat less.
These larvae tend to crawl quickly. Thus, experts believe that this is one of their ways to adapt to their habitat, where fast-moving predators lurk.
However, when a potential threat approaches them, they suddenly drop dead and stay still. In some cases, they may even deploy webs as a backup defense.
Another way that the larvae adapt is through overwintering. While other Lepidoptera species tend to do this during the pupal stage, these larvae seem to have adapted the hibernation techniques of woolly bears.
The female Salt marsh moth lays hundreds or even thousands of eggs at once – in one spot. She will die shortly after that.
The Salt marsh moths have these animals and insects as their natural enemies:
- Lady beetles (Coleoptera: Coccinellidae)
- Tachinid flies
- Assassin bugs (Hemiptera: Reduviidae)
- Parasitoid wasps (Ophion)
- Softwinged flower beetles (Coleoptera: Melydridae)
Distribution – Canada and the US
The Salt marsh moth is common in Canada. These are the sightings in the US:
Are salt marsh moths poisonous?
Salt marsh moth caterpillar may look dangerous, but it’s not poisonous. Its hairs don’t sting.
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Joan is a nocturnal person who loves traveling and coffee. She’s also an animal lover (and rescuer) who makes it a point to befriend every animal she meets. Her passion for learning led her to writing about various topics. As someone who is a nature lover, she aims to continue learning about the wonderful creation—especially butterflies, and at the same time, share her knowledge here at Butterfly Hobbyist.