Aim: We investigated the spatial and temporal patterns of diversification among colourful and flightless weevils, the Pachyrhynchus orbifer complex, to test the stepping-stone hypothesis of colonization across the Taiwan-Luzon volcanic belt.Location: Southeast Asia.Methods: The phylogeny of the P. orbifer complex was reconstructed from a multilocus data set of mitochondrial and nuclear genes using maximum likelihood in RAxML and Bayesian inference in MRBAYES. Likelihood-based tests in CONSEL were used to evaluate alternative tree topologies. Divergence times were estimated in BEAST based on a range of mutation rates. Ancestral range and biogeographical history were reconstructed using Bayesian binary MCMC (BBM) methods in RASP and in BioGeoBEARS. Demographic histories were inferred using the extended Bayesian skyline plot (EBSP). Species boundaries were tested using BPP.Results: The phylogeny of the P. orbifer complex indicated strong support for seven recip- The statistically delimited seven cryptic species imply that the diversity of Pachyrhynchus from small peripheral islands continues to be largely under-estimated.Main conclusions: The non-linear, more complex spatial and temporal settings of the archipelago and stochastic dispersal were probable key factors shaping the colonization history of the P. orbifer complex. Speciation of the P. orbifer complex may have occurred only between islands, indicating that peripatric speciation through the founders of stochastic dispersals was the major evolutionary driver.
K E Y W O R D Scryptic species, Kuroshio current, long-distance dispersal, oceanic islands, stepping-stone hypothesis, the Philippines, weevils
Abstract. We describe several new species of the previously monotypic Panjange lanthana species group from the Philippines and document their extraordinary morphology. Some species show strong male genital asymmetry, a phenomenon that seems to be exceedingly rare in spiders. Males of most species have eye stalks, and in two species these eye stalks are among the longest ever recorded in spiders. Some species show a tendency for male genital (pedipalp) elongation, and one species has the longest and thinnest palps ever recorded in Pholcidae. A cladistic analysis is performed including all described and several undescribed species of Panjange (except for one "problem species"), supporting the lanthana group and its close relationship with members of the possibly paraphyletic cavicola group.
Abstract. We describe eight new species of the genus Pholcus, and document their microhabitats. Four species are assigned to the previously described Pholcus ethagala group: P. tanahrata Huber sp. nov., P. uludong Huber sp. nov., and P. bukittimah Huber sp. nov. from the Malay Peninsula, and P. barisan Huber sp. nov. from Sumatra. These species are all litter-dwellers that build domed sheet webs on the undersides of large dead leaves on the ground. The other four species are assigned to newly created species groups: the P. tambunan group with two species from northern Borneo: P. tambunan Huber sp. nov. and P. bario Huber sp. nov.; and the P. domingo group with two species from the Philippines, Mindanao: P. domingo Huber sp. nov. and P. matutum Huber sp. nov. These latter four species are leafdwellers that build barely visible silk platforms tightly attached to the undersides of live leaves. The
R e s e a r c h a r t i c l eurn:lsid:zoobank.org:pub:404329BA-FD12-4F24-ABB6-0AC78A11DE54 1 main rationale for this paper is to provide part of the taxonomic and natural history background for upcoming phylogenetic and evolutionary (microhabitat shifts) analyses.
Aim We investigated the biogeographical history of an endemic Philippine treehopper, Pyrgonota bifoliata (Membracidae), to test the effect of Neogene geological events and Pleistocene climate change in generating speciation within the Philippines.Location The Philippine archipelago.Methods Phylogenies were reconstructed based on the mitochondrial cytochrome c oxidase I subunit (cox1) and nuclear wingless (wg) genes using maximum parsimony, maximum likelihood and Bayesian criteria. Divergence times were estimated in beast based on a range of mutation rates. Ancestral ranges were reconstructed using rasp (Reconstruct Ancestral State in Phylogenies) and Bayesian stochastic search variable selection (BSSVS). Species boundaries were tested using the Bayesian general mixed Yule coalescent (bGMYC) and Bayesian phylogenetic and phylogeography (BPP) methods.Results Pyrgonota bifoliata showed one of the lowest levels of between-Pleistocene island genetic variation among all the taxa examined. Most Pleistocene aggregate island complex (PAIC) lineages and extant P. bifoliata originated before the onset of the first extensive Pleistocene glacial cycle. Ancestral P. bifoliata originated in the late Miocene from Mindanao, followed by a sequential northwards colonization of the Visayan Islands and Luzon in the Pliocene-early Pleistocene, which coincided with the spatial reorganization of the Philippines. The statistically delimited nine provisional species of what we now view as the P. bifoliata species complex correspond to current island boundaries and specialized host plants.
Main conclusionsThe temporally calibrated phylogeny of P. bifoliata represents the first invertebrate study to support the hypothesis that Miocene-Pliocene geological events and consequent cross-island dispersal were pivotal promoters of species diversity in the Philippines. We hypothesize that ecological adaptation to specialized host plants, together with either local selection or genetic drift through within-island allopatric isolation, present a plausible in situ speciation mechanism for the origin of these herbivorous insects.
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