Small Tortoiseshell
Aglais urticae
The Small Tortoiseshell is a medium-sized butterfly belonging to the Nymphalidae family. It is distinguished by its striking orange-red wing coloration with black, yellow, and white patches along the forewing edge and a border of blue spots. The species is a synanthrope, inhabiting a wide range of open landscapes from gardens to high mountains, with larvae being almost entirely dependent on nettles.
Details
Identification
Orange-red upper wings, blue marginal crescents, three black spots on the leading edge of the forewings, underside of wings dark brown marbled.
Social behavior
Adults are solitary; caterpillars live gregariously in communal webs during their early stages.
Diet
Caterpillars feed monophagously on nettles. Adults feed on nectar from a variety of plants such as thistles, buddleia, or pussy willow.
Hunting strategy
Nectar foraging using a proboscis on various flowering plants.
Spawning substrate
Underside of leaves of the Common Nettle (Urtica dioica) in sunny locations.
Overwintering
Overwinters as an imago (adult butterfly) in frost-free, dark quarters such as cellars, attics, or hollow trees.
Ecology
Ecological role
Important pollinator for wild plants; serves as a food source for birds, spiders, and parasitoids in various life stages.
Natural predators
Insectivorous birds, spiders, assassin bugs, ichneumon wasps (e.g., Sturmia bella).
Competitor species
Other nymphalids using nettles as host plants, such as the European Peacock or the Map butterfly.
Ecosystem service
Pollination of flowering plants in gardens, agriculture, and nature.
Threats
Habitat loss, pesticide use, climate change, and intensive mowing of nettle patches.
Scientific profile
Profile
Distinguishing features
Characteristic blue marginal lunules on a black background on all wing edges; three prominent black spots on the leading edge of the forewings; underside of hindwings darkly colored (camouflage as a dry leaf).
Habitat
Ubiquitous; inhabits open landscapes, gardens, parks, forest edges, and agricultural areas up to alpine altitudes (approx. 3000 m).
Protection & threats
Main threats
Drought periods due to climate change (desiccation of food plants), intensive agriculture, pesticide use, loss of overwintering sites in buildings.
Population trend
Still common in large parts of Europe, but regional (e.g., Western Europe) significant population declines recorded since the 2000s.
Conservation measures
Protection of nettle patches in sunny locations, reduction of insecticides, preservation of natural overwintering sites.