On the Morphological and Genotypic Variations of Two Congeneric species of Banana Aphid Pentalonia (Homoptera: Aphididae) from India

Banana aphid Pentalonia has already been described in its two taxonomic forms from hosts of Zingiberaceae and Araceae were regarded as separate taxa, P. nigronervosa Coquerel and P. caladii van der Goot, respectively, based on morphological and molecular differences. Between the two species of Pentalonia tested in our earlier study, the nigronervosa speciesexpressed fitness for banana host plants and the caladii species for taro host plant suggesting strong genotype(aphids)-environment(host plants) interactions and increased genetic variation. This study shows the morphological variations of the two species and the isozyme variations of the two taxa from Araceae and Musaceae plants, respectively, an indicative of this separation as the laboratory-reared clones of banana aphidfrom the host plants also occur as two variants of the aphid species. In the existing conditions of information, the two species can be certainly considered as separate species.