Kingdom Animalia Class Insecta Family Pterophoridae Scientific name Platyptilia isodactylus | Phylum Arthropoda Order Lepidoptera Genus Platyptilia Rank Species | |
Similar Platyptilia calodactyla, Platyptilia, Platyptilia gonodactyla, Capperia britanniodactylus, Oxyptilus pilosellae | ||
The ragwort plume moth or ragwort crown-boring plume moth (Platyptilia isodactylus) is a moth of the Pterophoridae family. It is native to central Europe, Mediterranean North Africa and southern Europe. It has also been recorded from China. It has been introduced in Australia as a biological control agent for ragwort.
The wingspan is about 19–29 mm. The wings are pale fawn or brown in colour with dark bands at the ends and variable V or double V shaped dark brown bands approximately one third of the wing length from the wing tip. The body and legs are lighter brown. The forewing is divided into two lobes and the hindwing into three feather-like plumes. The middle and hind legs are very long and have prominent spines. Adults have a characteristic resting posture with the body and fully outstretched wings forming a T shape, the forewing covering the hindwing, and the hind legs raised and extended parallel with the body. Males have longer, thinner abdomens.
The larvae feed on Senecio jacobaea, Senecio aquaticus and Senecio nemorensis.
Life cycle
There are two generations per year. Adult moths are active in spring and autumn. Females lay an average of a hundred eggs during their lifetime, which is about 12 days. Newly hatched larvae burrow into the stalk of the leaf until they reach the crown. The larvae pass through five instars. Older larvae tunnel in the crown, stem and roots. Larvae eject their frass and shed head capsules from a small hole in the stem and this debris accumulates on silken webbing spun around the hole by the larva. The pupal stage lasts about one week.