Wingspan: 28–36 mm
Flight period of butterflies: in one generation from June to August
Host plants for caterpillars: medicinal burnet (Sanguisorba officinalis)
The Large Blue butterfly (Phengaris teleius or Maculinea teleius) is a large blue butterfly with a light gray-brown underside of the wings decorated with a pattern of white-edged black spots. The upperside of the wings in the male is silvery blue with a row of small, elongated to oval, black spots in the middle. On the outer edge of the male's wings runs a broad (about 2 mm), almost black band, the edge is adorned with white fringe. The female's underside is the same as the male's; the blue on the upperside of her wings is limited to the central part of the wings, the dark band along the edge of her wings also extends along the upper edge.
The Large Blue butterfly lives in wet meadows where the larval host plant grows and host ant species are present at the same time.
Similar to other butterflies in the genus Maculinea, the Large Blue also has an interesting and complex life cycle. When from the egg laid by the female on the inflorescence of medicinal burnet, the larva hatches, it first for several weeks feeds on developing seeds. When it grows enough the caterpillar crawls to the ground, where with its scent it attracts workers of a certain species of ant. The ant drags the caterpillar into its nest, there the butterfly larva begins to feed on the ant brood. When sufficiently developed, it pupates, then from the pupa emerges an adult butterfly, which must quickly escape from the ant nest, as it no longer smells like ants.
In Slovenia, the Large Blue butterfly is protected and listed as a vulnerable (V) species on the Red List. To preserve biodiversity for future generations, the European Community has listed it among Natura 2000 species, and with that Slovenia has also committed to protecting this species and its habitat.
