''Stygionympha vigilans'', the western hillside brown, is a butterfly of the family Nymphalidae. It is found in South Africa on the seaward side of the mountains from

Cederberg The Cederberg mountains are located near Clanwilliam, approximately 300 km north of Cape Town, South Africa at about . The mountain range is named after the endangered Clanwilliam cedar (''Widdringtonia wallichii''), which is a tree end ...

south to the Cape Peninsula in the Western Cape and along the Drakensberg mountains to Grahamstown in the

Eastern Cape The Eastern Cape is one of the provinces of South Africa. Its capital is Bhisho, but its two largest cities are East London and Gqeberha. The second largest province in the country (at 168,966 km2) after Northern Cape, it was formed in ...

. The wingspan is 45–48 mm. Adults are on wing from October to December and from August to April (with peaks from October to November and February). There are probably multiple generations per year. The larvae feed on

Poaceae Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...

grasses. Larvae have also been reared on ''

Ehrharta erecta ''Ehrharta erecta'' is a species of grass commonly known as panic veldtgrass. The species is native to Southern Africa and Yemen. It is a documented invasive species in the United States, New Zealand, Australia, southern Europe, and China ...

'' and '' Ischyrolepsis cinncinnata''.

References

Butterflies described in 1887 Satyrini Butterflies of Africa Taxa named by Roland Trimen {{Satyrini-stub