Spanish Festoon

• GeneralIts caterpillars feed on toxic plants and store the poison as a defence.
• It flies in a single generation each year and spends the rest of the time as a chrysalis, often for several years in a row if conditions are poor.
• It is protected by the legislation of several Spanish regions, and its conservation depends on keeping the banks and field edges where its food plant grows.
• Its caterpillar feeds exclusively on birthworts, plants loaded with aristolochic acids, and sequesters those toxic compounds, retaining them into adulthood. It is the same strategy used by the American butterflies of the genus Battus.
• Its red, black and yellow colours are an aposematic warning of that toxicity.
• It flies very early in the year, from February to May depending on the area, and has a single annual generation.
• The chrysalis overwinters attached to a stem and can remain like that for more than a year if conditions are unfavourable.
• Its strict dependence on birthworts makes it vulnerable to the ploughing-up of hillsides and to scrub clearance, and it is one of the species monitored by the Zerynthia association, which bears its name.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Mediterranean scrub with birthwort

Size at birth

The caterpillar is brown or greenish with reddish fleshy projections and hairs; the chrysalis measures about 2 cm, is brown with lengthwise ridges and looks like a splintered dry twig

Sexual maturity

A single generation a year, with the adults flying from March to June (February in the south); in the south of the Iberian Peninsula, North Africa and coastal areas there may be a second generation in autumn

Gestation / incubation

The caterpillar stage lasts roughly a month; the chrysalis, of the girdled type, is fixed to the substrate by a silk button and a band around it, and hibernates from May until March of the following year

Litter / clutch size

The eggs are laid one by one on the leaves and flower stalks of the food plant, always of the genus Aristolochia

Sources consulted: https://es.wikipedia.org/wiki/Zerynthia_rumina; Asturnatura, ficha Zerynthia rumina; Andalhuerto, ficha de la mariposa arlequin; Asturnatura; Naturaleza Para Todos, ficha Zerynthia rumina; Waste Magazine, guia de mariposas; Andalhuerto

Best time: From February to May, a single generation a year

The pins mark the parks where its presence is documented.