The ecology and conservation of Thestor brachycerus brachycerus (Trimen, 1883): an aphytophagous miletine butterfly from South Africa

Abstract

The existing knowledge of the biology and ecology of the butterfly genus Thestor is summarised, and the conservation status of the Critically Endangered Thestor brachycerus brachycerus reviewed. The biotopes of two hitherto unknown littoral colonies are compared with the known inland fynbos site. The size of the extant populations is recorded as a future monitoring baseline. The relationship between habitat structure and territorial behaviour of males is explored. Female oviposition substrates are recorded, and it is inferred that the larvae are aphytophagous. No correlation was detected between vegetation composition and the presence of butterfly populations. A requirement for low level male perching sites to engender territorial and thence mating behaviour was assessed as a key habitat resource. The commonest ant found in pitfall traps both within and outside the butterfly colonies was Anoplolepis custodiens, a known associate of Thestor butterflies. Future research should focus on determining the ant associations and food resources of all larval stages.