Acraea encedon

White-barred acraea
both Acraea encedon encedon
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Nymphalidae
Genus:	Acraea
Species:	A. encedon
Binomial name
Acraea encedon (Linnaeus, 1758)
Synonyms
Papilio encedon Linnaeus, 1758 Hyalites encedon (Linnaeus, 1758) Telchinia encedon (Linnaeus, 1758) Papilio encedonia Linnaeus, 1767 Papilio lycia Fabricius, 1775 Acraea sganzini Boisduval, 1833 Acraea lycia var. fulva Doubleday, 1848 Acraea daira Godman and Salvin, 1884 Acraea braunei Staudinger, 1885 Acraea lycia ab. infuscata Staudinger, 1885 Acraea usagarae Vuillot, 1891 Acraea encedon lycia ab. ascrepticia Strand, 1912 Acraea encedon ab. fumosa Aurivillius, 1913 Acraea encedon f. commixta Poulton, 1913 Acraea encedon f. alcippoides Le Doux, 1923 Acraea encedon var. nigeriae Schultze, 1923 Acraea encedon f. perradiata Le Cerf, 1927 Acraea encedon lycia f. carbonaria Le Cerf, 1927 Acraea encedon f. poultoni Le Doux, 1931 Acraea encedon f. infuscatoides Le Doux, 1931 Acraea encedon f. umbratalcippina Le Doux, 1931 Acraea encedon f. lycoides Le Doux, 1931 Acraea lycia f. fulvoides Le Doux, 1931 Acraea lycia encedonoides Le Doux, 1931 Acraea lycia f. aurantiaca Le Doux, 1931

Acraea encedon, the common acraea, white-barred acraea or encedon acraea, is a butterfly of the family Nymphalidae. It is found in tropical Africa and south-western Arabia. It is one of the species of Acraea sometimes separated in Telchinia.

Description

The wingspan is 40–50 mm (1.6–2.0 in), with the female being slightly larger than the male, but otherwise similar in pattern and colour. The apex of the forewing is blackish and divided by a white bar. The rest of the surface of the wings are usually orange with black spots, however paler varieties with a greyish or yellowish base colour are also found.

The butterfly is a polymorphic Müllerian mimic of Danaus chrysippus, which is a highly unusual phenomenon as Müllerian mimicry is almost always monomorphic.

Distribution

There are two subspecies:

• Acraea encedon encedon is found in Africa south of the Sahara and in Madagascar. In South Africa this species is absent from the dry western parts of the country, but common in KwaZulu-Natal coastal areas on the eastern side of the country.
• Acraea encedon rathjensi Le Doux, 1933 is found in south-western Arabia.

Life cycle

The eggs are oval in shape. The larvae feed on Commelina species, such as C. diffusa. The flight period of the adults is all year, but they are most common from March to May. They are slow fliers, and perch on low-growing vegetation.

In some populations there are two kinds of females, one producing offspring in a normal 1:1 sex ratio, the other producing females only. In other populations the sex ratio is apparently normal. Scientists first believed the distorted sex-ratio was caused by a driving W chromosome. Later research suggests it is caused by cytoplasmic bacteria.

Gallery

• 
  Acraea encedon from Eritrea; mounted specimen
• 
  Acraea encedon encedon
• 
  Larva of Acraea encedon encedon

Mimicry

A. encedon is a Müllerian mimic of the butterfly Danaus chrysippus, which is also prevalent in Uganda.

External links

• Die Gross-Schmetterlinge der Erde 13: Die Afrikanischen Tagfalter. Plate XIII 56 e as encedon, sganzini and lycia g as daira
• Images representing Acraea encedon at Bold
• Images representing Acraea encedon encedon at Bold
• All-female broods and mimetic polymorphism in Acraea encedon (L.) (Lepidoptera: Acraeidae) in Tanzania
• Sex ratio distortion in Acraea encedon (Lepidoptera: Nymphalidae) is caused by a male-killing bacterium