Apatura ilia

Apatura ilia, Espoo, 19.7.2012

Apatura ilia was a rare butterfly in Finland in early- to mid-2000s. First recorded in 2000, the species slowly grew more common, until after 2007 the influxes (also in 2009 and 2010) gave it a foothold on the southern coast of Finland. In Western Nyland (Uusimaa) region the ilia has displaced Apatura iris as the more common of the two. I saw my first iris in 2008 or -09, and my first ilia in 2010. Now I have seen five ilias in the span of two days. The species seems to have become established in the Helsinki region.

Identification is quite straightforward and easy. Large, dark and white-marked butterfly, with a yellow proboscis, distinct blue hue if seen well, rufous-white underparts and eyespots on the top of each wing (iris only has eyespots on the hindwing). Limenitis populi is larger, darker, without the blue hue or eyespots, and has a row of orange spots in the rear hindwing.

Larva lives on Salix caprea and other willows Salix spp., as well as Populus spp. (poplars and aspen). Favours forest edges, and flies relatively high. Often lands on bare soil, where it feeds on minerals; also likes trap liquids and rotten organic matter (feces, urea, carcasses etc.)