Cardenolide content of Danaus chrysippus butterflies from three areas of East Africa

Abstract

The African butterfly Danaus chrysippus, like other members of the family Danaidae, feeds as a larva on species of milkweeds (Asclepiadaceae). I t has been demonstrated in a sample from a West African population that only a minority of adult D. chrysippus accumulated detectable amounts of poisonous and presumably emetic cardenolides from their larval foodplants. It has also been shown in D. chrysippus and the related monarch butterfly (D. plexippus) that the cardenolide content of adults varies with that of their respective milkweed foodplants.Three population samples of D. chrysippus from sites in East Africa are analysed for cardenolides using the spectrophotometric technique refined by Brower, Edmunds lk Moffitt (1975). which allows the assay of individual butterflies. The East African samples all have a palatability spectrum with a considerably higher percentage of cardenolide-containing individuals than the West African one. This is discussed in t e r m of its effect on potential bird predators and the 'automimicry' of emetic by palatable individuals. In East Africa D. chrysippus is polymorphic and appears to act as a model in a complex mimicry ring, whereas in West Africa it is monomorphic and may have 'shed' most of its mimics. This latter hypothesis is discussed in the light of our results.

The evolution of cardenolide‐resistant forms of Na+,K+‐ATPase in Danainae butterflies

“…The possibility that observed changes at position 111 may have little effect on ouabain sensitivity on their own raises the interesting question of how other Danaus spp., which lack N122H, also manage to sequester CGs, albeit at generally lower levels relative to monarchs (Brower et al. 1975, 1978; Cohen 1985; Mebs et al.…”

Polymorphism of the tropical butterfly, Danaus chrysippus L., in Africa

“…All three have been invoked for Danaus chrysippus (Owen and Chanter, 1968;Owen, 1970;Edmunds, 1969Edmunds, , 1974Brower, Edmunds and Moffitt, 1975;Brower et a!., 1978;Smith, 1973Smith, , 1975aSmith, , b, c, 1976aSmith, , b, 1979Smith, , 1980Smith, , 1981. The explanations offered by these authors are plausible, diverse and mutually compatible.…”

Incomplete sexual isolation in sympatry between subspecies of the butterfly Danaus chrysippus (L.) and the creation of a hybrid zone

“…The polymorphism is unique among the 157 species of the subfamily Danainae (Ackery and Vane-Wright, 1984); it is, moreover, a surprising feature in an aposematic species that is chemically defended (Rothschild et al, 1975;Brower et al, 1975Brower et al, , 1978Brown, 1984; JA Edgar in litt. to DASS) and supports numerous mimics (Smith, 1973a(Smith, , 1976(Smith, , 1979Owen and Smith, 1993;Owen et al, 1994).…”