Reconstructing the nonadaptive radiation of an ancient lineage of ground?dwelling stick insects (Phasmatodea: Heteropterygidae)

Stick and leaf insects (Phasmatodea) are large terrestrial herbivorous arthropods known for masquerading as plant parts such bark, twigs leaves. Their evolutionary history is largely shaped by convergent evolution associated with adaptive radiations on geographically isolated landmasses that have repeatedly generated ground-dwelling ecomorphs. The members of one lineage, however, the Oriental Heteropterygidae, morphologically rather uniform, a predominantly lifestyle. phylogeny Heteropterygidae comprises approximately 130 described species controversial remains uncertain. In particular, systematic position giant Jungle Nymph Heteropteryx dilatata, whose males capable flight exhibit most plesiomorphic wing morphology among extant phasmatodeans, major interest to scientific community. Here, we analysed set seven nuclear mitochondrial genes infer covering group's overall diversity. divergence time estimation reconstruction historical biogeography resulted in an ancestral distribution across Sundaland long distance dispersal events Wallacea, Philippines South Pacific. We were able resolve relationships three principal subgroups revealed Dataminae, which contain entirely wingless small forms, sister group Heteropteryginae + Obriminae. Within Heteropteryginae, Haaniella recovered paraphyletic regard Heteropteryx. Consequently, must be considered subordinate taxon deeply embedded within flightless clade stick insects. Obriminae, Bornean Hoploclonia strongly supported earliest diverging lineage. Based this finding, recognize only two tribes equal rank Hoplocloniini trib. nov. Obrimini sensu latter, demonstrate previous tribal assignments do not reflect phylogenetic basal splitting event occurred between wing-bearing Miroceramia Pterobrimus remaining Obrimini. Philippine genus Tisamenus Ilocano hebardi, thus, transfer latter hebardi comb. synonymize Tisamenus. discuss character transformations light new results conclude current taxonomic diversity appears mainly driven allopatry result niche differentiation. This radiation thus best nonadaptive radiation.