Grayling – Hipparchia semele – Butterflies of Northumberland

Featured image: Grayling ([1] @Pete Eeles)

Class: Insecta
Order: Lepidoptera
Family: Nymphalidae
Subfamily: Satyrinae
Genus: Hipparchia
Species: Semele

Conservation status: Priority species within the Uk. Part of the Biodiversity Action Plan (BAP). Classified as ‘least concern’ on the IUCN Redlist [4].

Appearance:

Wingspan: Male: 51 – 56mm Female: 54 – 62mm [1]
Sexual dimorphism: little, females are slightly larger
Wing Shape: Wavy edges
Dorsal Wing: Dark brown white orange highlights. Contain two black spots on the forewing and one on the hind wing. There wing edge of the hind wing has a black border and all wings have a small white fringe.
Ventral Wing: Brown striated with a feint white stripe. Looks rock like.
Body: Simple brown with no distinguishing features.

The Grayling is extremely camouflaged in stony conditions as well as on tree bark [1].

Grayling male ([1] @Millerd)

Grayling male ventral wing ([1] @Vince Massimo)

Grayling female ([1] @Neil Freeman)

Grayling Female ventral wing ([1] @Mark Colvin)

Distribution:

The Grayling is found across almost all of Europe favouring dry infertile habitats [4]. Within Britain, the species is restricted to the coastline and is very rarely seen further inland [1,4,5].

Populations are often isolated from one another due to low numbers and small dispersal [1]. The population of the Grayling is declining worldwide [4].

Sheltered, sunny areas with lots of bare ground are suited for Graylings [1]. Sand dunes and dry grasslands are common popular habitats [4].

Life Cycle:

The Grayling has a single brood each year and commonly uses Bristle Bent (Agrostis curtisii), Early hair grass (Aira praecox) amongst others as the larval food plant [1]. In sand dunes at the coast, Marram grass (Ammophila araenaria) is often the main food plant [2,6].

Butterfly: Emerge during July peaking at late July/early August [1].

Egg: Eggs laid singularly upon the stems of their food plant or nearby ground debris [1]. They are laid white but fade into pale yellow as they mature. The eggs hatch after 2-3 weeks.

Caterpillar: Caterpillars hatch in August where they begin to feed on their food plant. They feed nocturnally and spend the daytime hiding at the base of the plant. [4]. The small caterpillar hibernates throughout winter in the base of the food plant before reawakening and resuming feeding in spring [1].

Pupa: Forms during May/June and lasts for around 4 weeks [1]. The pupa is found laid on the earth or a few centimetres under the soil [1]

Grayling egg ([1] @Pete Eeles)

Grayling Caterpillar ([1] @Reg Fry)

Grayling pupa ([1] @Pete Eeles)

Behaviour:

The Grayling will always rest with its wings closed [1,2,5]. This is because the ventral wing surface is extremely effective at camouflage amongst bare ground and tree bark. The wings will also be orientated towards the sun in an attempt to avoid leaving a shadow [5]. When disturbed they will fly away immediately before landing on another surface which enhances their camouflage, e.g. stones, bare ground, tree bark [2].

Adult butterflies will feed on many food plants with Birds-Foot Trefoil (Lotus corniculatus) and bramble (Rubus fruticosus) being common sources [1].

Males are territorial and there is an elaborate courtship ritual that takes place before mating [1,6]. The male and female land on bare ground and the male will open his wings onto the female and secrete pheromones from sent glands in the wing [6]. The female will touch these pheromones with her antennae and will be encouraged to mate.

Grayling in Northumberland:

grayling 2015.png — 2015 Grayling sightings in the Northeast [8].

North East England Status: Resident [7]

The Grayling is resident to Northumberland with strongholds in the coastal dunes, especially Holy island [7]. Graylings are frequently seen in the sand dunes of Northumberland although it is rare to see them in large numbers [5].

In 2015 there was a total of 109 Grayling sightings which was an improvement on 2014 but still much less than in 2006 when there was 612 [8]. The first sighting in Northumberland was the 2nd July and the last on the 24th August on Holy island [8]. However the Grayling must be one of the regions most under recorded species due to it only being found in the most remote areas of Northumberland [8].

References:

[1] UK Butterflies (2017) Grayling. http://www.ukbutterflies.co.uk/species.php?species=semele Accessed 06 February 2017

[2] Learn about butterflies (2017) Grayling http://www.learnaboutbutterflies.com/Britain%20-%20Hipparchia%20semele.htm Accessed 06 February 2017

[3] Butterfly Conservation (2017) Grayling http://butterfly-conservation.org/679-1024/grayling.html Accessed 25 February 2017

[4] IUCN redlist (2017) Hipparchia semele. http://www.iucnredlist.org/details/173254/0 Accessed 06 February 2017

[5] Cook NJ (1990) An atlas of the butterflies of Northumberland and Durham. Northumberland biological records centre, the Hancock museum. Newcastle Upon Tyne

[6] Hammersley D (2003) A butterfly notebook. The book guild ltd. East Sussex

[7] North East Butterflies (2017) Butterfly Species http://www.northeast-butterflies.org.uk/speciesb/butterflies.html Accessed 06 February 2017

[8] Fleming S, Waller I, Perkins M, Norman R, Dover, Donnelly A (2015) Butterfly summary 2015. Northeast England branch. Butterfly Conservation. http://www.northeast-butterflies.org.uk/download_files/2015ButterflyReport.pdf Accessed 25 February 2017