Meet the Cinnabar Moth: the ragwort regulator

A Cinnabar moth, also known as the Red and black moth, lives in Europe, North America, Australia, New Zealand, and Asia. It is unique for its bright colors and ability to control the spread of toxic ragwort plants.

Cinnabar Moth Species Summary

Scientific NameTyria jacobaeae
Family NameErebidae
KingdomAnimalia
GenusTyria
HabitatGardens, grassland, railway banks, woodland, heathland, and mature sand-dunes
RangeEurope, Russia, North America, and Australia
Host PlantsRagwort and groundsel
Moth DescriptionBlack body and legs with red and black broad wings
Caterpillar DescriptionThe larvae have black and yellow bands

Moth Description

Cinnabar moth
Cinnabar moth

The Cinnabar moth has a 1.26 to 1.61 inches (3.2 to 4.2 cm) wingspan and is about an inch long. The legs, body, and antennae are black.

The standard coloring of the forewings is black with a red stripe on the margins and two red spots on the wings’ rear end. It’s not uncommon to see yellow spots instead of red. The forewings can also be completely black or red with black borders, and the hindwings are red with a narrow black border.

the Cinnabar moth vs. the Burnet moth

Because of the moth’s black and red colors, they are often confused with Burnet mothsBurnet moths don’t have a red stripe; they only have red spots.

Why are they called Cinnabar Moths?

The red dots on the wings explain their name. Cinnabar is a bright red mineral that artists use for red pigment.

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the Cinnabar Larva Description

Cinnabar moth caterpillar
Cinnabar moth caterpillar

First instar Cinnabar moth larvae are yellow with a black head. With maturity, the color changes to a yellow and black banding with white hairs. Cinnabar moth caterpillars are voracious eaters and can grow up to 1.2 inches (3 cm) long. If they completely eat their host plants, they will become cannibalistic.

Cinnabar Moth Lifespan

Egg Stage5 to 14 days
Caterpillar Stage21 to 30 days
Chrysalis Stage14 to 21 days
Butterfly Stage5 to 14 days
Typical Duration of the Cinnabar Moth Lifespan

Where are cinnabar moths found?

Cinnabar moth can thrive in habitats containing ragworts, such as well-drained grasslands, mature dunes, and heathland. These moths also thrive in open areas such as woodlands and gardens.

Usual Host Plants

The primary host plant for Cinnabar moths is the common ragwort (Senecio jacobaea), but they can also feed on groundsels (Senecio vulgaris) and other ragworts.

Their scientific name, Tyria jacobaeae, also comes from the ragwort plant.

What do cinnabar moths eat?

Tyria jacobaeae are specialists, so the caterpillars and adult moths’ primary food sources are ragworts and groundsels. These plants contain alkaloid poison, but the moths are immune to it.

Behavior, hibernation, and flight

Cinnabar moths lay eggs under ragwort leaves and can lay up to 300 eggs in clusters of 30 to 60. The eggs take about two weeks to hatch. After hatching, they feed on the leaves and flowers of their primary food plants.

The poison in the ragwort leaves makes them unpalatable, but they don’t reach maturity in large numbers because they turn cannibalistic. The larvae are voracious eaters, so they exhaust the larval plants quickly and start eating each other.

During the first instars, the larva cluster together but space out at the fifth instar because of their feeding habits. The larva takes around one month to mature.

The caterpillars feed from July to September and pupate from September through winter.

Before pupation, the larvae form a cocoon and then hibernate in the ground, where they stay through winter. The pupa is red and about 3 cm long. They will then emerge as adult moths during summer.

Tansy ragworts’ toxicity is dangerous to animals such as horses, so Cinnabar moths are used as biocontrol agents.

Adult moths are active day fliers but can also appear at night. These moths emerge from May to August.

Predators

Although Cinnabar moths have toxic bodies and bright-colored wings to warn predators, they are still preyed on by:

  • Dragonflies
  • Beetle
  • Flies
  • Wasps
  • Birds of the cuckoo species
  • Reptiles
  • Bats

Any other natural Lepidoptera predator eat young caterpillars that have not assimilated the poison from the plants. Moles are the predators of these moths’ pupa when it hibernates in the soil.

What is the cinnabar moth’s range of flight?

Cinnabar moths are native to Europe, Central Asia, western Siberia, and China. These moths were later introduced to North America, Australia, and New Zealand to control the poisonous ragwort plant.

This Red and black moth is also well-distributed in the United Kingdom in various counties, including Scotland and England.

Do Cinnabar Moths Migrate?

There are no records of Cinnabar moths migrating. They live in the same place where they hatch.

Are Cinnabar Moths Poisonous?

Cinnabar moths are poisonous. Their primary food source, ragwort, contains a toxic alkaloid that the caterpillars ingest and store in their bodies. The toxins stay in their bodies even after they have pupated and become moths, making them poisonous to predators.

What are the symptoms of cinnabar moth poisoning?

Cinnabar moths don’t pose a significant threat to humans but can cause a rash if handled with bare hands. Unfortunately, these caterpillars can cause allergic reactions in cats and dogs.

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