Some aspects of zoogeography and speciation in the genusTeldeniaMoore (Drepanidae: Lepidoptera)

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Abstract
1.The Indo-Australian region is diverse having many oceanic islands on which much of the fauna is isolated. Dispersal may have taken place along Pleistocene land connections and since that time the sea has risen, thus separating populations which are now speciating independently. Over water migration has probably occurred to a limited extent. Some of the problems involved are discussed in relation to the Drepanid genus Teldenia. 2.Sundaland species occurring on Celebes possibly arrived there via the Philippines and not over water from Borneo. 3.Three species in the Teldenia niveata group occur in Celebes, indicating a multiple invasion. The topography and shape of Celebes lends itself to the speciation of its fauna. 4.Sundaland was probably the centre of the niveata species-group distribution, and specca is probably the species nearest to the ancestral form. 5.T. specca may have migrated north as far as Assam during the Pleistocene and diverged to form the species obsoleta, in Sundaland or Burma so the two are closely related, as are vestigiata and alba. 6.There is no evidence of introgressive hybridization in Teldenia. 7.The nigrinotata species-group extends from Celebes to Melanesia with latilinea confined to Celebes and psara to Ceram. Most other species occur on New Guinea or have radiated from there. T. sparsata may be the result of a second invasion of the ancestral home by nigrinotata. 8.The two forms of apata could represent intermediate stages in speciation since they have similar male genitalia but a different number of wing fasciae and occur on different islands. T. apata and helena may be derived from the New Guinea species inanis by over-water migration. T. moniliata is not likely to be closely related in spite of superficial external resemblance. 9.Wing markings are sometimes thought to be convergent and therefore misleading in showing relationships. Genitalia characters seem to be those most liable to undergo change. Interpretation of the phylogeny depends on whether wing markings are considered to be convergent and/or the genitalia characters divergent. Species, although isolated, may evolve the same phenotypes. This may apply to wing patterns. 10.The taxonomy of Teldenia is difficult, due in part to the number of grades of speciation found on the many oceanic islands. It has been difficult to decide what taxonomic rank some peripheral isolates and other border-line cases should take.