In a statement, the University of Porto centre explains that the discovery, published in the scientific journal SHILAP Revista de lepidopterologia, occurred during fieldwork carried out between Vila Nova de Milfontes and Cabo Sardão, to find "butterflies of the genus 'Ypsolopha', which in Spain feed on plants of the genus 'Ephedra'".
The investigation found "four adults and several small, brown caterpillars" which were later identified as a "new species to the Portuguese fauna".
In homage to the place of the discovery, Vila Nova de Milfontes, in the district of Beja, the researchers named this new species 'Ypsolopha milfontensis'.
This nocturnal butterfly stems from 'Ypsolopha rhinolophi Corley', a species described in 2019 in northern Portugal and France, presenting, however, "a very distinct ecology".
"While 'Ypsolopha rhinolopsi' feeds on black oak, the new species feeds on a threatened shrub endemic to the western Mediterranean region and the archipelagos of Madeira and Canary Islands," CIBIO-InBIO reveals, adding that this plant - known as gestrela or cornicabra - is classified as "vulnerable" on the red list of vascular flora of mainland Portugal.
"The reduction of its populations is mainly due to the destruction of habitat by urban and tourist pressure," he said.
According to the centre of the University of Porto, in Portugal, at least 381 species of vascular flora are threatened with extinction, as well as 44 percent of endemisms [taxonomic groups that develop in a restricted region]".
Quoted in the statement, Miguel Porto, researcher at CIBIO-InBIO and president of the Portuguese Botanical Society, says that the southwest Alentejo is "one of the regions where more threatened flora endemisms occur".
"On the one hand, it is a region of high concentration of endemisms, but on the other, it is a region that is subject to strong threats such as the large-scale expansion of intensive agriculture and urban tourist development," he adds.
The disappearance of endemics means the "extinction of animal species that depend on them", and researchers suspect that this new species of butterfly "is also at risk of extinction".
"In Portugal, we still know very little about our invertebrate fauna. Surely there are several other species in anonymity, dependent on the various endemic species of vascular plants of Portugal. It is urgent to study our cultural heritage, to know and preserve it", argues Sónia Ferreira, entomologist and researcher at CIBIO-InBIO.