Host plants:
The caterpillars feed on various Apiaceae. This can lead to the formation of regional preferences. So the caterpillar feeds in Provence mostly on Ptychotis saxifraga. Another preferred genus is Opopanax. In Samos Island I found larvae only on Opopanax hispidus. In Greece (e.g. Samos) larvae also occur on Ferula communis.
Habitat:
The caterpillars live mostly on plants that grow above especially hot gravel and open ground, as embankments, quarries and rocky slopes. Overall, Papilio alexanor inhabits mostly grasslands slopes with the larval habitats on special spots which are often interspersed with loose bushes.
In Samos Island the larvae can be recorded in roadside verges, woodland margins, open olive groves, rocky slopes and embankments with Opopanax hispidus.
Life cycle:
The adults fly in a single generation from late April to July. In Samos in 2009, the butterflies appeared in the first week of May. I found the eggs in Provence quite numerous about in mid-June. The caterpillar lives depending on the location from late May to early August. Pupation generally takes place on rocks, under stones or in cracks and crevices. In Samos Island I found a pupa in 2 metres height on the wall above a window outside a chapel. The pupa is therefore clearly flattened and hibernates.
Endangerment factors:
Papilio alexanor is threatened at the sometimes very local sites by bush encroachment and reforestation, overgrazing, tourism and in some places also through intensification (vineyards, etc.). In Greece and Turkey, the sites are less at risk.
Remarks:
The distribution is now split up like islands in Europe: Provence and a few spots in the adjacent NW-Italy, Southern Italy (northern Sicily and Aspromonte), Croatia, the southern Balkan Peninsula. Furthermore, Papilio alexanor occurs across Asia Minor and Israel to Pakistan, Afghanistan and Kazakhstan.