The adult moth is beautiful, slate-black with two red spots and two rosy stripes on each fore-wing, and with black bordered hind-wings that are also rosy red. It is named after the red mineral Cinnabar, which was once used as an artists’ pigment.
From May to July you might see the moths in the Reserve or along the Canal around the grasses and ragwort, perhaps during a sunny day, though they mostly fly at night.
A female will lay a few hundred eggs on the underside of the lower leaves of ragwort, in groups of around 50; on hatching in July the larvae are yellow and cluster for protection, but, as they feed and move up the plant to the flowers, they accumulate the plant’s bitter alkaloids, which stops the birds eating them. (If the plant is stripped, younger larvae may starve, or be eaten by their siblings).
At the same time the caterpillars’ colour changes into the typical fancy, golden-orange and black hoops, and long hairs grow. In the late summer of August, the mature caterpillars drop to the ground, and then spin a cocoon ready to overwinter in the soil. Next spring the adult moths will emerge to begin the cycle again.
Links to further information and images
Buglife
Natural History Museum
No comments:
Post a Comment
Comments welcome. Poetry suggestions gratefully received via the Contact form at the bottom of the blogger pages.