Puparia and third instar of a new diminutive whitefly, Regiominutus ventralis gen. et sp. nov. found infesting underside leaves of Aglaia elaeagnoides (A. Juss) (Meliaceae) on the Andaman Islands, India, are diagnosed, described and discussed. Regiominutus gen. nov. differs from allied genera, Aleuroclava Singh, Aericerus Dubey, Aleuroparvus Dubey, Aleuropleurocelus Drews and Sampson and Tetralicia Harrison in having a submarginal ventral groove, from the former two in having a deflexed submargin and smaller ventral surface and from the latter two in having a caudal furrow. Affinities and differences of the new genus shared with related genera are discussed. Puparium characters observed in slide mounts versus scanning electron microscope (SEM) images are presented. Line drawings, habitus images and SEM, microphotographs of the type specimens are given for the new taxa. This is the first whitefly species to be recorded from this host plant. [ABSTRACT FROM AUTHOR]