Thestor Butterfly and Anoplolepsis Ant
Thestor (Lepdoptera: Lycaenidae) comprises 27 recognized species, all of which are endemic to southern Africa. All species are believed to be parasitic, feeding on homopterans and/or the brood, regurgitations, and/or worker of the ant, Anoplolepis custodiens. The western Cape region contains by far the greatest concentration of species. Most prefer sparsely vegetated, arid or montane habitats, and have not been recorded on flowers.
Jack Boyle and I are using RAD tags of both the butterflies and the ants to investigate how Thestor has achieved such diversity if all species utilize the same food resource and are confined to a highly restricted distribution in the western Cape region of southern Africa.
Ecological theory would suggest that the degree of diversification exhibited by Thestor, all occurring in close proximity and on a single resource is not possible. The question, then, is: Did Thestor radiate onto a pre-existing template of Anoplolepis species, or did Thestor diversify with a contemporaneously-diversifying Anoplolepis template? Is Thestor significantly older or younger than the Anoplolepis with which it associates, or could the two have co-speciated? Were the diversifications of ants and lycaenids driven by similar geographic processes?
photo by Ada Kaliszewska