Sierra Nevada blue (Polyommatus golgus)
|Also known as:||Nevada blue, Niña de Sierra Nevada|
|Size||Wingspan: 26.3 - 29.8 mm (2)|
- The Sierra Nevada blue is a small blue butterfly from the Sierra Nevada Mountains, Spain.
- Male Sierra Nevada blues have blue upperwings, but in females the upperwings are dark brown with orange crescent-shaped markings.
- Sierra Nevada blue caterpillars initially live and feed on their host plant, but are later tended by a specific species of ant.
- Adult Sierra Nevada blue butterflies are generally only seen in July.
The Sierra Nevada blue is classified as Vulnerable (VU) on the IUCN Red List (1).
The Sierra Nevada blue, also known as the Niña de Sierra Nevada, is a flagship species of an endangered habitat within the Sierra Nevada National Park, Spain, where 53 endemic plant species and at least 50 endemic insect species occur, including this beautiful butterfly (3).
This species is sexually dimorphic, meaning its appearance differs between the sexes. While the lower sides of the wings are grey to brown with conspicuous patterning in both the male and female (4), the upper sides differ significantly. The upper sides of the male Sierra Nevada blue’s wings are an iridescent blue, with black margins along the edge of both the forewings and hind wings which quickly diffuse towards the centre of the wing. In contrast, the upper sides of the female Sierra Nevada blue’s wings are brown to almost black (2) (4), with small orange, crescent-shaped markings present along the margins of the hind wings but absent from the forewings (2).
The newly hatched caterpillars of the Sierra Nevada blue are creamy-yellow, gradually becoming light green with a darker green to black head. The caterpillars also have long white hairs on the body which, together with the green colouration, help camouflage the caterpillars against the leaves of their host plant (2).
The Sierra Nevada blue is so called due to its distribution within the Sierra Nevada Mountains in southern Spain, and populations are known to exist in both the Granada and Almeria provinces (5). This species is endemic to the region, meaning it only occurs in this part of southern Spain (1).
A subspecies of the Sierra Nevada blue found in Sierra de la Sagra, Polyommatus golgus sagratrox, is sometimes considered to be a separate species, Polyommatus sagratrox (1) (2).
The host plant on which the Sierra Nevada blue lays its eggs and which the caterpillars eat is Anthyllis vulneraria pseudoarundana. This plant occurs at elevations of 2,200 to 3,400 metres and is endemic to the Sierra Nevada region (6). It is one of the few plants that can withstand the extreme weather in this region, which is covered in snow for nine months of the year (1) (3). Anthyllis vulneraria pseudoarundana is part of a grassland community characterised by strong-rooted perennial plants which lie close to the ground due to the harsh conditions in this mountainous region (3) (4).
The Sierra Nevada blue is generally found in open patches of creeping juniper scrub and in acidic grassland and meadows growing on slate rocks and schist (1) (2) (3) (4) (7).
The adult Sierra Nevada blue butterflies emerge in July and feed on nectar from plants such as Spanish sandwort (Arenaria tetraquetra), rock campion(Silene rupestris), Jasione amethystina and mouse-ear hawkweed (Hieracium pilosella), which are abundant at this time of the year (3) (4) (7). Adult male Sierra Nevada blues are known to defend perching sites against other males (3).
The female Sierra Nevada blue lays her eggs in late July, placing them singly on the upper side of curled leaves of the host plant, Anthyllis vulneraria pseudoarundana (3) (4) (7). The eggs of this butterfly are usually greenish-white to light green (2). Once the caterpillar hatches, it feeds on the host plant until it reaches its third instar (the larval stage after a moult), after which it is tended to by ants, Tapinoma nigerrimum, over winter (2) (3) (4) (7). This species of ant often sites its nests next to the food plant of the Sierra Nevada blue (3) (4) (7).
Pupation in the Sierra Nevada blue occurs after the fifth instar the following June, and takes place within the soil close to the food plant (4) (7). The pupa or chrysalis of this species is generally a brownish-green to pale yellowish colour and measures up to 8.5 millimetres in length (2).
While the Sierra Nevada blue is considered to be globally rare as its entire range is restricted to a small part of Europe (8), its localised populations appear to be abundant (3).
Due to its restricted range, any changes to the native vegetation could have a negative impact on this species. The main threat to the Sierra Nevada blue is development in the area for the tourism and skiing industries, including activities such as construction of new roads and buildings and reshaping of slopes, which can substantially alter the composition of local vegetation (1) (3) (4) (7). A threat for the future may be climate change (1), which could potentially shift the Sierra Nevada blue’s range to higher elevations where the habitat is not suitable for this species (4).
The Sierra Nevada blue currently has a stable population (1) (9) and is listed under Annex II of the Bern Convention (10) and Annexes II and IV of the Habitats Directive (11). Both are international agreements to conserve endangered habitats and species within Europe and legally require member states to suitably protect and manage these habitats and the species within them (10) (11). The habitat of the Sierra Nevada blue is also part of the Sierra Nevada National Park and is a Biosphere Reserve, affording this species further protection (2) (4) (7).
Education is important for the conservation of the Sierra Nevada blue and the National Park. Many species are at the southernmost limit of their range in this area, so the populations there are important for protecting the species’ genetic diversity, and awareness of this scientifically important area needs to be raised (3) (7). In addition, more information is required on the distribution, populations and ecology of the Sierra Nevada blue, and its habitat needs to be appropriately managed and protected from development (1) (3) (4).
Finally, it will also be important to clarify whether the populations of the Sierra Nevada blue in the Sierra de la Sagra are in fact a separate species, P. sagratrox (4).
Find out more about the Sierra Nevada blue:
Atlas de los Invertebrados Amenazados de España - Polyommatus golgus:
Libro Rojo de los Invertebrados de España - Polyommatus golgus:
More information on butterfly conservation in Europe:
Butterfly Conservation Europe:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Genetic diversity: the variety of genes within a particular species, population or breed causing differences in morphology, physiology and behaviour.
- Instars: development stages of an immature insect. At the end of each instar, the insect sheds the rigid external skeleton (the exoskeleton), enabling it to grow and form a new, larger exoskeleton.
- Larval: of or relating to the immature stage in an animal’s lifecycle, after it hatches from an egg and before it changes into the adult form. Larvae are typically very different in appearance to adults; they are able to feed and move around but are usually unable to reproduce.
- Moult: in insects, a stage of growth whereby the hard outer layer of the body (the exoskeleton) is shed and the body becomes larger.
- Perennial: a plant that normally lives for more than two years. After an initial period, the plant usually produces flowers once a year.
- Pupa: in some insects, a stage in the life cycle during which the larval form is reorganised into the adult form. The pupa is usually inactive, and may be encased in a chrysalis, cocoon or other protective coating.
- Pupation: the process of becoming a pupa, the stage in the life cycle of some insects during which the larval form is reorganised into the adult form. The pupa is usually inactive, and may be encased in a chrysalis, cocoon or other protective coating.
- Sexual dimorphism: when males and females of the same species differ in appearance.
- Subspecies: a population usually restricted to a geographical area that differs from other populations of the same species, but not to the extent of being classified as a separate species.
IUCN Red List (June, 2012)
- Gil-T., F. (2003) Polyommatus (Plebicula) sagratrox (Aistleitner, 1986): Ecología, morfología comparada de sus estadios preimaginales con los de Polyommatus (Plebicula) golgus (Hübner, 1813), taxonomía y nuevos argumentos para su validez específica (Lepidoptera, Lycaenidae). Boletín de la Sociedad Entomológica Aragonesa (S.E.A.), 33:219-227.
- Munguira, M.L. and Martin. J. (1993)The Sierra Nevada blue, Polyommatus golgus (Hiibner). In: New, T.R. (Ed.) Conservation Biology of Lycaenidae (Butterflies). IUCN, Gland, Switzerland.
Munguira, M.L., Cano, J.M., García-Barros, E. and Pajarón, J.L. (2008) Polyommatus golgus (Hübner, ). In: Verdu, J.R. and Galante, E. (Eds.) Atlas de los Invertebrados Amenazados de España (Especies En Peligro Crítico y En Peligro). Direccion General para la Biodiversidad, Ministerio de Medio Ambiente, Madrid. Available at:
- Ibañez, S. and Gil-T., F. (2009) First records of the endemic Polyommatus golgus (Hübner, 1913) and Agriades zullichi (Hemming, 1933) in Almería province (E. Sierra Nevada, S. Spain). Atalanta, 40(1/2):191-192.
- Gil-T., F. (2007)The correct hostplant of Polyommatus golgus (Hübner, 1813): Anthyllis vulneraria pseudoarundana H. Lindb. (Lepidoptera, Lycaenidae). Atalanta, 38(1/2): 199-202.
Munguira, M.L., Martín, J. and García-Barros, E. (2005) Polyommatus golgus. In: Verdú, J.R. and Galante, E. (Eds.) Libro Rojo de los Invertebrados de España. Dirección General de Conservación de la Naturaleza, Madrid. Available at:
- Van Swaay, C.A.M. and Warren, M.S. (1999) Red Data book of European Butterflies (Rhopalocera). Nature and Environment, No. 99, Council of Europe Publishing, Strasbourg.
- Van Swaay, C.A.M. and Warren, M.S. (2006) Prime Butterfly Areas of Europe: an initial selection of priority sites for conservation. Journal of Insect Conservation, 10:5-11.
Council of Europe: Bern Convention (March, 2013)
EU Habitats Directive (March, 2013)