- Subfamily: Pyrginae
- Wingspan: 28-32 mm
- Flight period: Apr - Oct
- Spread: Common
- Host plants: Malva sylvestris, Althaea officinalis
The Carcharodus alceae also called Scarce Swallowtail is a large butterfly with a wingspan of 64-85 mm.
It is widespread throughout Europe with the exception of Ireland and Norway, in Italy it is absent from Sardinia *.
The butterfly is white or yellowish with typical zebra lines (5 or 6), dark brown or black, starting from the costal area, wider, to reach by narrowing the anal area; the area facing the body tends to be dark. The hind wings, also white or yellowish, have the sub marginal region of black or dark brown color with lunulae of intense blue color. The anal area of the same presents a blue ocellus, surrounded by black and with, in the upper part, an orange lunula; under it depart the long tails, characteristic of the family, black with clear apex. The lower pages of the wings represent the same design as the upper pages with more washed out colors. **
Bi or trivoltine is a species with migratory tendency , it frequents different habitats, from sunny grasslands to temperate forests from the basal to the mountain level. The Scarce Swallowtail , although still common, has a declining population due to habitat loss and the scarcity of host plants. In some European countries and protected species. In some provinces of Austria it is considered rare or threatened with extinction. In Italy it is still a fairly common species. The threat to this species at European level has not yet been assessed.
The larval stage lasts from 5 to 8 weeks and brings the caterpillar to the size of 40 - 50 mm. With a bright light green color, sometimes with darker points, the caterpillar is very reminiscent of terrestrial isopdes or slugs.
The larvae feed on shrub and Rosaceae species such as Prunus sp. (in particular Prunus spinosa) and Crataegus monogyna.***
* Lepidoptera mundi https://lepidoptera.eu/ - Fauna Europea https://fauna-eu.org/
** Bestimmungshilfe für die in Europa nachgewiesenen Schmetterlingsarten - http://lepiforum.de/
*** Farfalle d'Italia http://www.farfalleitalia.it/