The Violet Copper (Lycaena helle)

With a wingspan of only 25-30 mm, the Violet Copper (Lycaena helle) is a rather small species of butterfly from the family of Coppers. However, it impresses with its iridescent, metallic, purple-blue wing colour. Its colour does not fade because it is not the result of pigments. Instead, depending on the viewing angle of the observer, the amazing colour effect is created by the refraction of light. The colourful shimmer extends over the whole body of the male. The female has a striking appearance as well, showing the characteristic bluish shimmer in individual bands and spots, especially along the edges of the wings.

Habitat and way of life

The Violet Copper inhabits moist meadow fallows or nutrient-poor to moderately nutrient-rich wet meadows with abundant populations of Common Bistort, which is the only food plant for caterpillars of this butterfly species in Germany. Egg-laying also occurs exclusively on this plant. Common Bistort grows in microclimatically cooler locations. In northeastern Germany (and Eastern Europe), the Violet Copper produces two generations of butterflies per year, in southern and western Germany only one generation. In the Euskirchen district, the species produces one generation per year. The adult butterflies can be seen from May to June, depending on the weather conditions of the year. The adults only live for 7 to 14 days. Females lay eggs, which resemble small golf balls, on the underside of Common Bistort leaves. The caterpillars that hatch from the eggs initially feed on the undersides of this caterpillar food plant. After moulting several times, the caterpillars pupate and, unique among coppers, overwinter as pupae in dry litter close to the ground.

“The populations of Violet Copper are sensitive to intensive mowing or grazing regimes and to elevated nutrient levels. If left unmanaged for too long, its habitat becomes overgrown with shrubs; the butterfly can tolerate this for a while because open moist forests are its original habitat. However, if it becomes too shady, eventually it will disappear from these areas as well. The Violet Copper also requires effective connectivity between its occurrences – the next suitable habitat should not be too far away. Its greatest threat, however, is climate change. As a species adapted to cool summers and cold winters, conditions are gradually becoming too warm. It has already abandoned the lowlands of the Westerwald and Eifel regions and is now restricted to areas of higher elevations in these locations. Moving even higher up is not possible as the species has already reached the highest possible elevations in these areas at around 650 to 700 meters above sea level.

Lycaena helle is listed in Annex IV of the EU Habitats Directive. This allows conservation authorities to carry out EU-funded LIFE projects to improve the species’ population status, such as those in the North Rhine-Westphalian part of the Eifel region. The Violet Copper is one of the most endangered butterfly species in Europe!