It is an accepted fact that biological pools are habitats for amphibians and many other aquatic living beings. This photo of a caterpillar reveals that other types of animals also take advantage of these poles of biodiversity. The photo was sent by an owner of a biological pool, along with the question if this caterpillar’s hunger wasn’t harmful to plants on the shore? Fortunately this is not the case, because it is a caterpillar of Vanessa virginiensis. That is, a diurnal butterfly, whose larvae never eat so much of their favorite plant that it will just die.
The species has a rather funny history, being originally from North America. More than 50 years ago, it was found for the first time in mainland Portugal at Praia de Santa Cruz, Torres Vedras. It was also seen in the Azores and Madeira, where it is rare to this day. As there is no evidence that man is responsible for the arrival of this American species to Europe, this is one of the rare cases where a “new” species arrived in Europe by its own. It is known that some species of butterflies are able to fly thousands of kilometers, because there are migratory species as known in the avifauna as well.
Fortunately, for this species of butterfly there is no evidence that it is harmful in any way to autochthonous flora or fauna, that is, original to Portugal. The caterpillar lives on thistles and nettles and also likes Pseudognaphalium lutei-album, a species of wetland plant, with hairy, whitish foliage, which is used to beautify the margins of biological pools. Thus, these, for some part of the year, become cradles for a daytime butterfly of American origin, but now considered Portuguese, which will delight with its flights throughout the summer.