The caterpillars of the Southern Festoon live on various birthworts, such as Aristolochia clematitis, Aristolochia rotunda, Aristolochia pallida and Aristolochia pistolochia. Because their foodplants grow in different habitats and the caterpillars also have different foodplants in different areas, this spring butterfly can be found in quite different habitats. In the western part of its range, it can be seen in open places along rivers with the foodplant Aristolochia rotunda. In the mountains, the butterflies can be seen in dry, sunny, rocky places, where Aristolochia pallida and Aristolochia pistolochia grow. In the Pannonian region, the species is found on sites with ruderal vegetation, e.g. along the Danube, but also in vineyards on sunny slopes, where Aristolochia clematitis grows as a weed. In Greece, the butterfly occurs in damp areas, as well as on dry slopes, according to the species of birthwort used as foodplant. The eggs are laid singly or in small groups on the underside of the leaves, where the caterpillars are usually also found. The caterpillars have a striking appearance. Mostly beige with black spots, they have some orange tubercles on each segment, each ending in a black, spiny tuft. The Southern Festoon has one generation a year and hibernates as pupa. Habitats: dry calcareous grasslands and steppes (14%), humid grasslands and tall herb communities (12%), mesophile grasslands (12%), heath and scrub (9%), dry siliceous grasslands (7%), sclerophyllous scrub (7%), alluvial and very wet forests and brush (7%).
Zerynthia polyxena, the southern festoon, is a butterfly belonging to the butterfly family Papilionidae.
The southern festoon can reach a wingspan of 46–52 mm. The females have slightly longer wings, usually lighter colored than males. The basic color of the wings is yellow, with a complicated pattern of several black bands and spots.
On the edges of the hindwings they have a black sinuous line with a series of blue and red warning spots to deter potential predators (aposematism). The body is dark brown and bears red patches on the sides of the abdomen.
This species is rather similar to, and can be confused only with, the Spanish festoon (Z. rumina). The differences are in the presence of blue on the hind wings of Z. polyxena and the relatively lower amount of red on its forewings compared with Z. rumina. The ranges of these two species overlap only in southeast France.
The caterpillars of Z. polyxena are up to 35 millimeters long. They are initially black, then they are yellowish with six rows of fleshy orange and black spikes all over the body.
T. polyxena Schiff. & Den. (= hypermnestra Scop.hypsipyle Fabr.). Light yellow, with spots and dentate lines , the hindwing bearing red submarginal spots. South Europe , from Southern France to the Black Sea, and Asia Minor. — In ab. rumina Esp.). the black costal spots of the forewing bear red centres, also on the upperside, while usually such red dots are found only in some places of the underside. This form is not rare in some localities, for instance in the West of the Balcan Peninsula. — Specimens in which the black colour is extended are known as ab. cassandra Hb. (= demnosia Frr., creusa Meig.) (9f); the proportional extent of black is, however, individually very variable. Such melanotic specimens occur everywhere singly as aberrations, but are found as the only form in some localities, for instance Dalmatia. — ab. ochracea Stgr. (=polymnia Mill.) (9f) is the name of individuals in which the light yellow colour is replaced by a magnificent dark yellow. Also this form occurs everywhere among the ordinary form, but is in certain places especially plentiful. — ab. meta Meig. (= flavomaculata Schilde, rufescens Oberth., rumina, alba Esp) (9f), however, is everywhere a rare aberration, the red colour of the purple spots being replaced by dark yellow. — In ab. bella Neub. the third costal spot is reduced. — The full-grown larva reddish yellow r black-brown, with pointed setiferous tubercles; in May and June on Aristolochia, especially in moist and warm localities. The statement that the larva feeds also on Quercus ilex is doubtless occasioned by an error of identification. The pupa is very slender, being yellowish grey, marked with brown. [2]
Z. polyxena is widespread in the middle and southern Europe (southeastern France, Italy, Slovakia and Greece) covering all the Balkans and reaching the south of Kazakhstan and the Urals. Although they are widespread they occur only locally.[3][4]
These rare butterflies can be found in warm, sunny and open places such as grassy herb-rich meadows, vineyards, river banks, wetlands, cultivated areas, brushy places, wasteland, rocky cliffs and karst terrains, at an elevation of from 0 to 1,700 metres above sea level but usually below 900 metres.
Male
Male bottom
Female
Female bottom
It is an early spring butterfly. Adults fly from April to June in a single brood. The adults are active for no more than three weeks. The females lay their eggs singly or in small groups at the bottom of the host plants. When found in the wild they prefer to live and lay their eggs in densely vegetated areas, and there is a positive correlation between number of leaves on the host plant and number of eggs laid by females.[5] The eggs are spherical and whitish at first, bluish colored before hatching. The caterpillars feed on birthworts (mainly (Aristolochia clematitis, Aristolochia rotunda, Aristolochia pistolochia, Aristolochia pallida).[6] The special food of the larvae provides the toxic substances which then also go to the adults, making them unpalatable. The young caterpillars feed at first on flowers and young shoots, while after the second molt they feed on leaves. The pupae stay linked to a support by a silk belt for wintering and the new adults hatch the next spring.
Under the rules of the International Code of Zoological Nomenclature, Article 1.3.4, names used only below the rank of subspecies do not enter into consideration in zoological nomenclature; infrasubspecific names do not have formally recognized authorship, and do not compete for priority or homonymy with names used for species or subspecies. Accordingly, all of the names used for "forms" of Z. polyxena listed below must be disregarded as having no nomenclatural standing whatsoever, even though many are presented with authors and dates.[7]
Subspecies and forms include:[1][4]
This article incorporates text from this source, which is in the public domain. 
{{cite web}}: CS1 maint: date and year (link) CS1 maint: url-status (link) Zerynthia polyxena, the southern festoon, is a butterfly belonging to the butterfly family Papilionidae.
