- Subfamily: Pierinae - Pierini
- Wingspan: 30-50 mm
- Flight period: Mar - Oct
- Spread: Common
- Host plants: Asteraceae - Brassicaceae - Tropaeolaceae
The Pieris napi also known as Green-veined White is a medium-sized butterfly of the Pieridae family with a wingspan of 30-50 mm.
It is distributed throughout Europe, in Italy it is absent only from Sardinia. *
The Pieris napi is generally whitish in color, has gray-greenish streaks or grayish scales in correspondence with the veins of the lower part of the rear wing. This characteristic is less pronounced in the individuals of the summer generations, and the ribs appear thinner (second and third generation) which are very similar to Pieris rapae . The upper pages of the wings have apexes and dark spots, more accentuated in the female specimens, a characteristic that differentiates the sexes. **
The Pieris bryoniae species was once considered a sub-species of the Pieris napi , The similarity especially on the lower page is evident but in the upper pages of the male wings they have very accentuated ribs in females they are even completely tinged with brown, but this species can only be found in grasslands and forest clearings at high altitude.
Widely distributed throughout Italy and the islands from the basal to the mountain level in meadows with flowers, sparse forests, uncultivated areas, wet grasslands, edges of paths and river banks. Bi or trivolina, adults can be observed from March to October (in the mountain plain, it is often monovoltine). The eggs, laid singly on the host plant, have an elongated shape, and are found between March and September. It overwinters as a greenish pupa attached to host plants or on other supports. The caterpillars are visible from April to October, are green in color and have no yellow streaks on the back unlike the Pieris rapae .
They are rarely found on cultivated varieties of the Brassica genus but feed on various species of Brassicaceae such as Alliaria petiolata, Arabis alpina, Brassica campestris, Brassica oleracea, Brassica rapa, Cardamine amara, Raphanus sativus, Rorippa islandica, Rorippa sylvestris, Thlaspi arvensis. You can also meet on the leaves of these plants: Calendula officinalis (fam. Asteraceae), Reseda odorata (fam. Resedaceae), Tropaeolum majus (fam. Tropaeolaceae).
* Lepidoptera mundi https://lepidoptera.eu/ - Fauna Europea https://fauna-eu.org/
** Bestimmungshilfe für die in Europa nachgewiesenen Schmetterlingsarten - http://lepiforum.de/