Tyria jacobaeae - common in Europe and Asia

Order: Lepidoptera
Family: Arctiidae

Now it's well known that I am no lover of moths. In fact, I'm no big fan of any insect that flies around at night - the humble bat is a great friend of mine for feasting on them all, from moths to daddy longlegs (aka cranefly) through June Bugs. This said, it may surprise you that one of my favourite insects is the cinnabar moth.

It's a pretty little thing, this critter, with startling red-and-black wings flitting through the meadows and grass verges of England. It's slightly unusual too, because unlike most moths, it is active to some extent during daylight hours, giving us the chance to see the little beauty. With a wingspan of about 1½ inches (40 mm), it is plain to see, as well.

The caterpillar is quite striking too - black and yellow stripes, it gorges itself on ragwort and occasionally, the related groundsel and other Senecio plants. In fact, so effective is it at noshing the weed down, that it has been introduced as a biological control in places where the plant is a problem, especially New Zealand.

Lifestyle and Other Facts

The insects lay their eggs (most often on ragwort) in clusters of about 80 during the summer months, and after two weeks, the pale yellow larvae appear - as they grow, they develop the "wasp" colouration of distinctive black-and-yellow banding around their bodies, which can reach nearly 1¼ inches (30 mm) in length.

As they grow, they eat not just the foliage of the plant, but also the flowers, which respond by producing even more flowers, in order to try and spread their seed. As the plants are annuals, this prevents them spreading. Given that ragwort is toxic and can cause illness in some animals, it is of concern to farmers. The moth was introduced to many habitats (most especially in the Antipodes) for this very reason.

The larvae tend not to get eaten by predators, partly because of their unpleasant taste and poisonous nature, and partly because of their warning colours. (They are, however, susceptible to attack by some species of ichneumon wasp, which lay their eggs in the bodies of the caterpillars.) They go through five stages of development, and will feed for some weeks, finally clustering around the growing tops of the plants before pupating and overwintering.

The adults emerge in the late Spring, when they mate, lay their eggs (up to 800 per female) and begin the cycle over again. The adults are certainly beautiful, their wings striped and spotted with a rich, rusty red, just the colour of cinnabar (mercury ore). To my mind, they are a great delight, and I become a child again each time I see one, in field or hedgerow.

Keen personal observation

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