Cladistic analysis of Maladera (Omaladera): Implications on taxonomy, evolution and biogeography of the Himalayan species (Coleoptera: Scarabaeidae: Sericini)

The phylogeny of Maladera (subgenus Omaladera) is investigated with morphological data. Twenty-one species or subspecies in one of four subgenera of Maladera (Macroserica, Maladera, Cephaloserica, and Omaladera) were included in the cladistic analysis, with Stilbolemma sericea chosen as the outgroup. Data were analysed using two approaches, the parsimony ratchet and heuristic search with successive weighting based on the rescaled consistency index. The results of both analyses provide evidence for the monophyly of the subgenus M. (Omaladera) and the group of species occurring in the Himalayas. Each of the three principal lineages of Omaladera has diversified independently in separate geographical regions. The present phylogenetic hypothesis provides no evidence that faunal exchange has occurred between these regions as regards ancestral and terminal taxa of Omaladera. The phylogenetic analyses support the hypothesis that the strictly parapatric M. himalayica, M. incola, M. immunda, and M. thakkholae are valid species rather than subspecies.