Our own elusive butterfly on Zandrivier Farm - Elandsbergia
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This small and beautiful butterfly was discovered on the summit of the Elandsberg mountains by E.L. and A.B. Pringle on 29th December 1982. There on the southern edge of the Karoo, the males fly on rocky ridges in arid Mountain Renosterbosveld, (referred to in Acocks (1975) as veld type 43, with some Macchia (Fynbos) elements).
A male will patrol its chosen, elevated rocky prominence, waiting for a female to ascend and mate. The males defend their territory vigorously against other males. After mating, the female will descend and search the slopes for suitable foodplants on which to lay her eggs. She will only do so if a certain species of ant is present on the foodplant. The butterflies in this genus are commonly referred to as "Opals", this is because of the opal-like colour on the wings, but also for the deeper blue iridescence on the wings of males when light is reflected at certain angles. Females have rather more orange markings, have more rounded wings and they lack the iridescence. This genus of butterflies are known for associating with certain ants during their larval stages. The ants are usually a species of "cocktail ant" (Crematogaster sp.). These ants tend the caterpillars and protect them from predators in exchange for a special nectar exuded from a dorsal gland by the caterpillar. During the early evening, the caterpillars emerge from their hiding places beneath the foodplant to feed on the foliage whilst some of the ants rush about looking for any enemy predators. The most likely foodplants for this butterfly are Zygophyllum and Thesium, both of which are present in suitable places on the mountain and were also growing close to where females were seen. On this trip it was noted that Crematogaster ants were present on both likely foodplants. This butterfly is on the wing during the months of October to December. Although its existence has been known for 25 years, it was only scientifically described and named by Heath & Pringle in 2007. It was described conservatively as a subspecies of Chrysoritis adonis adonis from the Gydo Mountain near Ceres, however, its behaviour and other small differences suggest it may be a distinct species in its own right. The ongoing molecular work at Harvard University (USA) may throw more light on its true status, as researchers compare its DNA with other closely related species. |
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