Taxonomy

Aglais urticae | Small Tortoiseshell | Ruán beag

Distribution

Status

Conservation status

Ireland: Least Concern (Regan et al., 2010)
Europe: Least Concern (van Swaay et al., 2010)
Climate risk category: Climate Change Risk; present distribution in Europe can be explained by climate to a moderate extent (Settele et al., 2008)

Legal status

The Small Tortoiseshell is not afforded legal protection in Ireland.

Native status

Resident

Species Biology

Identification

Key identification features include:

  • Medium size, wingspan: 45 - 62 mm
  • Alternating black and yellow bands on front of forewing
  • Necklace of deep blue spots on upper wing
  • Contrast between very dark and much lighter mottling on hindwing

Habitat

Generalist on wide variety of habitats, including: tall herb and grassy forest clearings, fallow crops, field margins, urban parks and
gardens. Adults select sheds, attics or other similar sites for roosting prior to hibernation, and then choose these sites for hibernation. In spring, adults frequently roost low within nettle patches and bask on a variety of flowers (Bond & Gittings, 2008).

Flight period

Bivoltine: overwintering adults appear on the wing as early as February in favourable weather, and continue until about mid-May, peaking in April. Summer adults appear about the end of June, and increase until late August and early September, when increasing numbers enter hibernation, with late specimens flying well into October (Bond & Gittings, 2008).

Life cycle

Eggs are laid on the underside of the near-terminal leaves of the foodplant, in clusters of about 80, with some eggs piled up on top of others. Small plants on the southeastern edge of nettle patches are most favoured. The young larvae live gregariously within the retreat, but as the plant becomes defoliated groups of larvae move to another plant to continue feeding. The silken structure becomes festooned with faeces, larval skins and plant fragments. Later the larvae become solitary. Feeding occurs both by day and by night. Prior to pupation the larvae disperse several metres to pupate suspended from vegetation about one metre above ground. Larvae occur mainly from May to June and again from July to August, but possibly in three generations in warm summers. This species overwinters as an adult (Bond & Gittings, 2008).

Food plants

Specialist, larva primarily feed on Common nettle (Urtica dioica) and rarely on Dwarf Nettle (U. urens).

Flowers visited

Generalist, the adult’s nectar sources include: Bramble (Rubus fruticosus), Carline Thistle (Carlina vulgaris), Dandelion (Taraxacum agg.), Devil's-bit Scabious (Succisa pratensis), Field Scabious (Knautia arvensis), Greater Stitchwort (Stellaria holostea), Hawkweeds (Hieracium/Hypochoeris), Heather (Calluna vulgaris / Erica spp.), Hemp Agrimony (Eupatorium cannabinum), Ivy (Hedera helix), Knapweeds (Centaurea spp.), Marjoram (Origanum vulgare), Primrose (Primula vulgaris), Privet (Ligustrum vulgare), Ragwort (Senecio jacobaea), Thistles (Cirsium spp. and Carduus spp.), Thyme (Thymus polytrichus) and Water Mint (Mentha aquatica).

Distribution

World distribution(GBIF)

Small tortoiseshell is widely distributed in the northern hemisphere from the western European Atlantic to the Asian Pacific (Nash, et al, 2012).

Irish distribution

Found throughout the country.

Temporal change

Records submitted to Data Centre in 2020

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References

Publications

Bond, K.G.M. and Gittings, T. 2008. Database of Irish Lepidoptera. 1 - Macrohabitats, microsites and traits of Noctuidae and butterflies. Irish Wildlife Manuals, No. 35. National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Dublin, Ireland.

Regan, E.C., Nelson, B., Aldwell, B., Bertrand, C., Bond, K., Harding, J., Nash, D., Nixon, D. and Wilson, C.J. 2010. Ireland Red List No. 4 – Butterflies. National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Ireland.

Settele, J., Kudrna, O., Harpke, A., Kühn, I., Van Swaay, C., Verovnik, R., Warren, M.S., Wiemers, M., Hanspach, J., Hickler, T. and Kühn, E. 2008. Climatic risk atlas of European butterflies. Sofia-Moscow: Pensoft.

Van Swaay, C., Cuttelod, A., Collins, S., Maes, D., López Munguira, M., Šašic, M., Settele, J., Verovnik, R., Verstrael, T., Warren, M., Wiemers, M. and Wynhof, I. 2010. European Red List of Butterflies. Luxembourg: Publications Office of the European Union.

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