The Elban population is at risk of extinction because it lives in an area of ​​a few square kilometers located near the town of San Piero in Campo, where its host plants (Aristolochia rotunda and Aristolochia lutea) are present. This area is composed of abandoned fields and, due to the continuous growth of shrubs, there is a decrease in the number of host plants available for oviposition and larval growth. In 2019, to better protect this population, a new branch of the Butterfly Sanctuary was inaugurated, which includes some of the most important areas for the conservation of Z. cassandra on the island of Elba. Here, the National Park in collaboration with the University of Florence and the Circolo Arcipelago Toscano of Legambiente carries out interventions to favor the development of Aristolochia by carrying out precise pruning of the vegetation that hinders the development of these seedlings which are fundamental for the maintenance of the Z. cassandra population.