with an oblong, orange spot at the back corner and a relatively long tail. This species is rather similar to Papilio machaon, Papilio hospiton, Papilio alexanor and Protographium marcellus. Biology Adults of Iphiclides podalirius fly from March to October. There are one, two, or three generations a year. Caterpillars are polyphagous feeding on Crataegus (Finland), Crataegus monogyna (Palaearctic), Malus pumila and Malus domestica (Palaearctic), Prunus (Finland, Palaearctic), Prunus armeniaca (Palaearctic, Spain), Prunus avium (Palaearctic, Spain) Prunus cerasus (Palaearctic, Russia), Prunus domestica (Palaearctic), Prunus dulcis (Palaearctic, Spain), Prunus padus (Palaearctic), Prunus persica (Palaearctic), Prunus spinosa (Palaearctic), Pyrus (Palaearctic) and Sorbus aucuparia (Palaearctic). The caterpillars spin little pads on leaves and grip them firmly. The newly hatched caterpillar is dark in colour with two smaller and two bigger greenish patches on the dorsal side; later they are greenish with yellowish dorsal and side stripes. The summer chrysalids are green as a rule, the hibernating ones are brown. A number of hibernating chrysalids fall prey to various enemies. The caterpillars of the scarce swallowtail have been noted to leave silk trails from the permanent resting sites to feeding sites. This has been seen in both solitary and territorial larvae with larvae having the ability to discern their trails from those of others. Research on pupae of Iphiclides podalirius in Spain indicates that the pupae manifest in two colours, green and brown, for the purpose of camouflage. The green pupae develop on host plants and develop directly while brown pupae enter into diapause in the leaf litter. Pupating larvae tend to form green pupae before August while after August they tend to form brown pupae. Duration of the photophase or light period appears to be the mechanism which dictates the path of development of the pupa. The results suggest that the green pupa develop on food plants to avoid predation by small mammals and visual avian predators while the brown pupa develop on leaf litter to avoid avian predators. Life cycle References External links Scarce swallowtail on Butterflycorner.net Lepiforum.de Paolo Mazzei, Daniel Morel, Raniero Panfili Moths and Butterflies of Europe and North Africa Iphiclides podalirius on Guy Padfield's Butterfly Page Butterfly Conservation Armenia Iphiclides Butterflies of Asia Butterflies of Europe Butterflies described in 1758 Taxa named by Carl Linnaeus