Dixeia pigea

Ant-heap White
Male Dixeia pigea
Female Dixeia pigea
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Pieridae
Genus:	Dixeia
Species:	D. pigea
Binomial name
Dixeia pigea (Boisduval, 1836)
Synonyms
Pieris pigea

The Ant-heap Small White^[1] or Ant-heap White^[2] (Dixeia pigea) is a butterfly in the Pieridae family and is native to Africa.

Two females of different forms viewed from the side

Description

The wingspan is 40–48 mm for males and 40–52 mm for females.^[3] The upperside of the wings of males is pure white with a narrow black forewing tip and small black dots on the hindwing margin.^[1] The underside is whitish with two rows of black spots on the hindwings,^[1] with the inner row sometimes absent or incomplete. The female has several colour forms,^[1] but is usually pale yellowish-white on the uppersurface with heavier black markings than the male,^[1] and has a dark spot on each forewing. There is a rare female form (luteola^[3]) where the upperside is orange-yellow^[1] or deep apricot.^[3] The underside of females is similar to the male but the rows of black dots are more pronounced and the base colour is pale to bright yellow. Another rare form (rubrobasalis) has orange suffusion at the base of the underside of the forwing^[1] and a creamy-yellow upperside.^[3] The dry season form (alba^[3]) has reduced black markings.^[1] A distinguishing feature of D. pigea is that the hindwing costal has a yellow streak, unlike other Dixeia species.^[3]

• 

  Female form rubrobasalis from Limpopo Province, South Africa Photo: Sharp I.C. & Sharp A.

• 

  Male viewed from the side; showing the yellow streak on the hindwing

Distribution

This species is found from the Eastern Cape Province of South Africa through KwaZulu-Natal, Swaziland, Mpumalanga and Limpopo Province,^[4] to Mozambique, Zimbabwe, Ethiopia, DRC, Angola, and Cameroon.^[2]

Life Cycle

Pupa of Dixeia pigea

Eggs

Groups of tiny, elongated eggs are laid on the undersurface of the leaves of the foodplants.

Larvae

The larvae are green in colour; pale green on the back and darker green on the sides when young, and develop two rows of pale green blotches down the length of the body as they grow older. The foodplants are Capparis sepiaria and Capparis tomentosa.^[1]

Pupae

The pupae have an unusual shape, with a pointed 'nose' and a notable spike on each side of the body protruding from a broad, flattened area mid way down the body. There is a smaller spike both to the fore and rear of each of these larger spikes, and a small spike on each side of the body just to the rear of the head. The larger spikes resemble to some extent the double, hooked thorns on the stems of the foodplant, Capparis tomentosa (see image). The pupae may be pale green, dark green or brown in colour. The wing areas show whitish or yellowish with dark spots near to hatching and the body becomes greyish.

Adults

The flight period is all year.^[1] They have been described as having a medium-fast, random flight pattern^[1] or as a rather weak, slow flying butterfly.^[5] They keep to open areas^[1] in riverine forest and thick bush^[5] or the edges of bush areas.^[1] Both sexes feed from flowers^[1] and are greatly attracted to flowering bushes exposed to the sun.^[5]

Gallery

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  Larvae of Dixeia pigea; just a few days old

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  Older Larvae

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  Larvae; the one on the left is near to pupating

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  Larva about to pupate

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  Brown coloured pupa

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  Green coloured pupa

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  Underside of female pupa; yellow wings showing through

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  Pupa near to hatching

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  Female hatching from pupa

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  Female extending wings after hatching

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  Side view of female

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  Captive raised female released onto larval foodplant

References

1. ^ ^{a b c d e f g h i j k l m n} Williams, M. (1994). Butterflies of Southern Africa; A Field Guide. Southern Book Publishers. ISBN 1-86812-516-5.
2. ^ ^{a b} Markku Savela's pages: Dixeia, retrieved 4 August 2010.
3. ^ ^{a b c d e f} Woodhall, S. (2005) Field Guide to Butterflies of South Africa Struik Publishers, Cape Town. ISBN 1-86872-724-6.
4. ^ Biodiversity data provided by: Data contributors to the Southern African Butterfly Conservation Assessment (SABCA) (list of contributors accessible here: http://sabca.adu.org.za/thanks.php), a joint project of the South African National Biodiversity Institute, the Animal Demography Unit, University of Cape Town, and the Lepidopterists' Society of Africa (accessed via SABCA’s online virtual museum, http://sabca.adu.org.za/vm_redirect.php, 04-08-2010).
5. ^ ^{a b c} Cooper, R. (1973). Butterflies of Rhodesia.