To and fro in the archipelago: Repeated inter-island dispersal and New Guinea's orogeny affect diversification of Delias, the world's largest butterfly genus.

The world's largest butterfly genus Delias, commonly known as Jezebels, comprises ca. 251 species found throughout Asia, Australia, and Melanesia. Most species are endemic to islands in the Indo-Australian Archipelago or to New Guinea and nearby islands in Melanesia, and many species are restricted to montane habitats over 1200 m. We inferred an extensively sampled and well-supported molecular phylogeny of the group to better understand the spatial and temporal dimensions of its diversification. The remarkable diversity of Delias evolved in just ca. 15-16 Myr (crown age). The most recent common ancestor of a clade with most of the species dispersed out of New Guinea ca. 14 Mya, but at least six subsequently diverging lineages dispersed back to the island. Diversification was associated with frequent dispersal of lineages among the islands of the Indo-Australian Archipelago, and the divergence of sister taxa on a single landmass was rare and occurred only on the largest islands, most notably on New Guinea. We conclude that frequent inter-island dispersal during the Neogene-likely facilitated by frequent sea level change-sparked much diversification during that period. Many extant New Guinea lineages started diversifying 5 Mya, suggesting that orogeny facilitated their diversification. Our results largely agree with the most recently proposed species group classification system, and we use our large taxon sample to extend this system to all described species. Finally, we summarize recent insights to speculate how wing pattern evolution, mimicry, and sexual selection might also contribute to these butterflies' rapid speciation and diversification.

Addendum to "Leaf insects from Luzon, Philippines, with descriptions of four new species, the new genus Pseudomicrophyllium, and redescription of Phyllium (Phyllium) geryon Gray, 1843, (Phasmida: Phylliidae)".

At the time Cumming et al. (2017) was published, the GenBank accession numbers for partial cytochrome c oxidase subunit I (COI) DNA barcode sequences from Microphyllium specimens sampled in the phylogenetic analysis were not yet available. This information is provided in Table 1.

Leaf insects from Luzon, Philippines, with descriptions of four new species, the new genus Pseudomicrophyllium, and redescription of Phyllium (Phyllium) geryon Gray, 1843, (Phasmida: Phylliidae).

Examination of unidentified Phylliidae specimens revealed a number of undescribed species from the island of Luzon, Philippines. Morphological and molecular study of specimens from the obscure phasmid genus Microphyllium Zompro, 2001, revealed a new species, which we describe as Microphyllium haskelli Cumming sp. nov.. It is here described and differentiated from the two other species in the genus, both currently only known from adults of a single sex. Pseudomicrophyllium Cumming gen. nov. is described as a new genus within Phylliidae with the type species Pseudomicrophyllium faulkneri Cumming gen. et sp. nov. as the sole known species in the genus. As is unfortunately often the case in the leaf-mimicking family Phylliidae, this new genus and species is only known from a single specimen. In addition to the new genus, two new Phyllium (Phyllium) species from the siccifolium species-group are named and described as Ph. (Ph.) antonkozlovi Cumming sp. nov. and Ph. (Ph.) bourquei Cumming Le Tirant sp. nov.. In addition to the newly described species, Phyllium (Phyllium) geryon Gray, 1843 is redescribed from a nearly perfect specimen, completing some of the morphological knowledge gaps currently missing because of the severely damaged holotype specimen. A key to all known species of Phylliidae from Luzon is included. Holotype specimens for all four new species will be deposited in the National Museum of the Philippines type collection and paratype specimens will be deposited into the San Diego Natural History Museum collection or retained within the first author's collection.