Revision of the New Caledonian endemic genus Gracilipsodes (Trichoptera: Leptoceridae: Grumichellini)

The taxonomy and systematics of the New Caledonian endemic caddisfly genus Gracilipsodes Sykora, 1967 (Trichoptera: Leptoceridae: Grumichellini) are reviewed. Seven new species represented by males are described and illustrated: Gracilipsodes aoupiniensis sp. nov. , Gracilipsodes aureus sp. nov. , Gracilipsodes aurorus sp. nov. , Gracilipsodes grandis sp. nov. , Gracilipsodes koghiensis sp. nov. , Gracilipsodes lanceolatus sp. nov. , and Gracilipsodes robustus sp. nov. Molecular phylogenetic analyses are applied to discern the relationships among the species of the genus and their closest relatives, based on sequence characters from the nuclear gene translation elongation factor-1α (EF-1α) and the three mitochondrial genes cytochrome oxidase I (COI), COII, and ribosomal large subunit (16S). The data are analyzed using parsimony and Bayesian inference, revealing a monophyletic Gracilipsodes with the eastern Australian monotypic genus Triplexa as its closest relative. Gracilipsodes is in turn divided into two major lineages.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 153 , 425–452.     

Cryptic species,gene recombination and hybridization in the genus Spiraeanthemum (Cunoniaceae) from New Caledonia

The Oceanian plant genus Spiraeanthemum (Cunoniaceae) has a centre of diversity in New Caledonia, where it is represented by seven species. Its diversification was investigated using two low‐copy nuclear genes, ncpGS and GapC, and phylogenetic analyses were based on maximum parsimony, maximum likelihood and recombination networks. We detected several cases of gene recombination in both datasets, and these have obscured the history within the genus. For S. ellipticum and S. pubescens, accessions from southern populations on ultramafic soils were genetically distinct from accessions from northern populations on non‐ultramafic soils. Given that no obvious morphological characters distinguish northern and southern populations in either taxon, both may be considered as examples of cryptic species. Incongruence between gene trees and species' delimitation may be explained by the parallel evolution of similar morphology, differential lineage sorting leading to differential fixation of alleles or different introgression patterns in the north and south leading to allele displacement. In New Caledonia, some species with broad ecological preferences may thus be artificial concepts. This suggests that they should be treated more critically in monographs and that the species' richness of the New Caledonian flora may be underestimated. Problems associated with the typification of S. ellipticum and evidence of hybridization events in the history of Spiraeanthemum are also discussed. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 137–152.     

New Caledonian biogeography: a reply to Murienne

This note replies to criticisms raised by Murienne (Journal of Biogeography, 2010, doi: 10.1111/j.1365‐2699.2010.02321.x ). Herein it is argued that assuming distributions in New Caledonia are caused by current environmental factors overlooks the possible importance of regional tectonic history for the biogeography.     

The effect of environmental diversification on species diversification in New Caledonian caddisflies (Insecta: Trichoptera: Hydropsychidae)

Aim To test whether environmental diversification played a role in the diversification of the New Caledonian Hydropsychinae caddisflies. Location New Caledonia, south‐west Pacific. Methods The phylogeny of the New Caledonian Hydropsychinae caddisflies was hypothesized using parsimony and Bayesian methods on molecular characters. The Bayesian analysis was the basis for a comparative analysis of the correlation between phylogeny and three environmental factors: geological substrate (ultrabasic, non‐ultrabasic), elevation and precipitation. Phylogenetic divergence times were estimated using a relaxed clock method, and environmental factors were mapped onto a lineage‐through‐time plot to investigate the timing of environmental diversification in relation to species radiation. The correlation between rainfall and elevation was tested using independent contrasts, and the gamma statistic was calculated to infer the diversification pattern of the group. Results The diversification of extant Orthopsyche–Caledopsyche species began in the Middle–Late Oligocene, when much of the island of New Caledonia was covered by ultrabasic substrate and mountain forming was prevalent. Most lineages originated in the Middle–Late Miocene, a period associated with long‐term climate oscillation. Optimization of environmental factors on the phylogeny demonstrated that the New Caledonian Hydropsychinae group adapted to ultrabasic substrate early in its evolutionary history. The clade living mostly on ultrabasic substrate was far more species‐rich than the clade living mostly on non‐ultrabasic substrate. Elevation and rainfall were significantly correlated with each other. The lineage‐through‐time plot revealed that the main environmental diversification preceded species diversification. A constant speciation through time was rejected, and the negative gamma indicates that most of the diversification occurred early in the history of the clade. According to the inferred phylogeny, the genus Orthopsyche McFarlane is a synonym under Caledopsyche Kimmins, and Abacaria caledona Oláh & Barnard should also be included in Caledopsyche. Main conclusions The age of the radiation does not support a vicariance origin of New Caledonian Hydropsychinae caddisflies. Environmental diversification pre‐dates lineage diversification, and thus environmental heterogeneity potentially played a role in the diversification of the group, by providing a variety of fragmented habitats to disperse into, promoting speciation. The negative gamma indicates that the speciation rate slowed as niches started to fill.     

Time and tempo of diversification in the flora of New Caledonia

New Caledonia is well known for its rich and unique flora. Many studies have focused on the biogeographical origins of New Caledonian plants but rates of diversification on the island have scarcely been investigated. Here, dated phylogenetic trees from selected published studies were used to evaluate the time and tempo of diversification in New Caledonia. The 12 plant lineages investigated all appear to have colonized the island < 37 Mya, when New Caledonia re‐emerged after a period of inundation, and the timing of these arrivals is spread across the second half of the Cenozoic. Diversification rates are not particularly high and are negatively correlated with lineage age. The palms have the fastest diversification rates and also the most recent arrival times. The lineage ages of rainforest plants suggest that this ecosystem has been present for at least 6.9 Myr. The New Caledonian flora is apparently a relatively old community that may have reached a dynamic equilibrium. Colonization by new immigrants has been possible until relatively recently and diversity‐dependent processes may still be affecting the diversification rates of the earlier colonizers. Further studies on the diversification of large plant clades with exhaustive sampling should help to clarify this. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 170 , 288–298.     

Molecular phylogeny of the endemic Philippine rodent Apomys (Muridae) and the dynamics of diversification in an oceanic archipelago

We analysed the phylogenetic relationships of ten of the 13 known species of the genus Apomys using DNA sequences from cytochrome b . Apomys, endemic to oceanic portions of the Philippine archipelago, diversified during the Pliocene as these oceanic islands arose de novo . Several of the speciation events probably took place on Luzon or Mindanao, the two largest, oldest, and most topographically complex islands. Only one speciation event is associated with vicariance due to Pleistocene sea-level fluctuation, and a Pleistocene diversification model in which isolation is driven by sea-level changes is inconsistent with the data. Tectonic vicariance is nearly absent from the Philippines, in which tectonic coalescence plays a significant role. Most speciation events (about two-thirds) are associated with dispersal to newly developed oceanic islands. The data imply that the species have persisted for long periods, measured in millions of years after their origins; further implications therefore are that faunal turnover is very slow, and persistence over geological time spans is more prominent than repeated colonization and extinction. Neither the equilibrium nor the vicariance model of biogeography adequately encompasses these results; a model incorporating colonization, extinction, and speciation is necessary and must incorporate long-term persistence to accommodate our observations.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society, 2003, 80 , 699–715.     

Species' diversity in the New Caledonian endemic genera Cephalidiosus and Nobarnus (Insecta: Heteroptera: Tingidae), an approach using phylogeny and species' distribution modelling

The patterns of local endemism in New Caledonia were analysed in two endemic genera of Tingidae (Insecta, Heteroptera), Cephalidiosus and Nobarnus , through a phylogenetic analysis and species' distribution modelling. The aim was to determine the possible causes of diversification and endemism in New Caledonia. Our results show that environmental conditions are probably important for the distribution of the genus Cephalidiosus , in conjunction with other factors such as resource (host plant) distribution, but suggest that the same environmental conditions have not influenced the speciation processes and diversification in the genus.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 177–184.     

Panbiogeography of New Caledonia: a response to Heads (2008)

The definition of areas of endemism is one of the most important steps for historical biogeography. Here I review the dataset used by Heads (Journal of Biogeography, 2008, 35 , 2153–2175) for his panbiogeographical analysis of the New Caledonian biota. I highlight that some of the distribution data appear dubious (some localities should have been included while some others should have been deleted) when compared with current databases. In addition, some conclusions are not supported by the data themselves.     

Immediate impacts of invasion by Wasmannia auropunctata (Hymenoptera: Formicidae) on native litter ant fauna in a New Caledonian rainforest

Abstract For the last 30 years, Wasmannia auropunctata (the little fire ant) has spread throughout the Pacific and represents a severe threat to fragile island habitats. This invader has often been described as a disturbance specialist. Here we present data on its spread in a dense native rainforest in New Caledonia. We monitored by pitfall trapping the litter ant fauna along an invasive gradient from the edge to the inner forest in July 1999 and March 2000. When W. auropunctata was present, the abundance and richness of native ants drops dramatically. In invaded plots, W. auropunctata represented more than 92% of all trapped ant fauna. Among the 23 native species described, only four cryptic species survived. Wasmannia auropunctata appears to be a highly competitive ant that dominates the litter by eliminating native ants. Mechanisms involved in this invasive success may include predation as well as competitive interactions (exploitation and interference). The invasive success of W. auropunctata is similar to that of other tramp ants and reinforces the idea of common evolutionary traits leading to higher competitiveness in a new environment.     

A multi-locus plastid phylogenetic analysis of the pantropical genus Diospyros (Ebenaceae), with an emphasis on the radiation and biogeographic origins of the New Caledonian endemic species

We aimed to clarify phylogenetic relationships within the pantropical genus Diospyros (Ebenaceae sensu lato), and ascertain biogeographical patterns in the New Caledonian endemic species. We used DNA sequences from eight plastid regions (rbcL, atpB, matK, ndhF, trnK intron, trnL intron, trnL-trnF spacer, and trnS-trnG spacer) and included 149 accessions representing 119 Diospyros species in our analysis. Results from this study confirmed the monophyly of Diospyros with good support and provided a clearer picture of the relationships within the genus than in previous studies. Evidence from phylogenetic analyses suggests that Diospyros colonized New Caledonia multiple times. The four lineages of Diospyros in New Caledonia also differ in their degree of diversification. The molecular data indicate that one lineage is paleoendemic and derived from an ancient Australian species. The other three lineages are more closely related to several Southeast Asian species; two of them are neoendemics, and one has radiated rapidly and recently.     

Biogeographical affinities of the New Caledonian biota: a puzzle with 24 pieces

Aim The distributions of many New Caledonian taxa were reviewed in order to ascertain the main biogeographical connections with other areas. Location Global. Methods Panbiogeographical analysis. Results Twenty‐four areas of endemism (tracks) involving New Caledonia and different areas of Gondwana, Tethys and the central Pacific were retrieved. Most are supported by taxa of lower and higher plants, and lower and higher animals. Main conclusions Although parts of New Caledonia were attached to Gondwana for some time in the mid‐Cretaceous, most of the New Caledonian terranes formed as oceanic island arcs and sections of sea floor bearing seamounts. The flora and fauna have evolved and survived for tens of millions of years as metapopulations on ephemeral islands. Later, the biotas were juxtaposed and fused during terrane accretion. This process, together with the rifting of Gondwana, explains the biogeographical affinities of New Caledonia with parts of Gondwana, Tethys and the Pacific.     

Reticulate evolution and sea‐level fluctuations together drove species diversification of slipper orchids (Paphiopedilum) in South‐East Asia

South‐East Asia covers four of the world's biodiversity hotspots, showing high species diversity and endemism. Owing to the successive expansion and contraction of distribution and the fragmentation by geographical barriers, the tropical flora greatly diversified in this region during the Tertiary, but the evolutionary tempo and mode of species diversity remain poorly investigated. Paphiopedilum, the largest genus of slipper orchids comprising nearly 100 species, is mainly distributed in South‐East Asia, providing an ideal system for exploring how plant species diversity was shaped in this region. Here, we investigated the evolutionary history of this genus with eight cpDNA regions and four low‐copy nuclear genes. Discordance between gene trees and network analysis indicates that reticulate evolution occurred in the genus. Ancestral area reconstruction suggests that vicariance and long‐distance dispersal together led to its current distribution. Diversification rate variation was detected and strongly correlated with the species diversity in subg. Paphiopedilum (~80 species). The shift of speciation rate in subg. Paphiopedilum was coincident with sea‐level fluctuations in the late Cenozoic, which could have provided ecological opportunities for speciation and created bridges or barriers for gene flow. Moreover, some other factors (e.g. sympatric distribution, incomplete reproductive barriers and clonal propagation) might also be advantageous for the formation and reproduction of hybrid species. In conclusion, our study suggests that the interplay of reticulate evolution and sea‐level fluctuations has promoted the diversification of the genus Paphiopedilum and sheds light into the evolution of Orchidaceae and the historical processes of plant species diversification in South‐East Asia.     

Historical biogeography and diversification within the Neotropical parrot genus Pionopsitta (Aves: Psittacidae)

Aim We investigate spatial and temporal patterns of diversification within the Neotropical avifauna using the phylogenetic history of parrots traditionally belonging to the genus Pionopsitta Bonaparte 1854. This genus has long been of interest for those studying Neotropical biogeography and diversity, as it encompasses species that occur in most Neotropical forest areas of endemism. Location The Neotropical lowland forests in South and Central America. Methods Phylogenetic relationships were investigated for all species of the genus Pionopsitta and five other short‐tailed parrot genera using complete sequences of the mitochondrial genes cyt b and ND2 as well as 26 plumage characters. The resulting phylogeny was used to test the monophyly of the genus, investigate species limits, and as a framework for reconstructing their historical biogeography and patterns of diversification. Results We found that the genus Pionopsitta, as previously defined, is not monophyletic and thus the Chocó, Central American and Amazonian species will now have to be placed in the genus Gypopsitta. The molecular and morphological phylogenies are largely congruent, but disagree on the position of one of the Amazon basin taxa. Using molecular sequence data, we estimate that species within Gypopsitta diversified between 8.7 and 0.6 Ma, with the main divergences occurring between 3.3 and 6.4 Ma. These temporal results are compared to other taxa showing similar vicariance patterns. Main conclusions The results suggest that diversification in Gypopsitta was influenced mainly by geotectonic events, marine transgressions and river dynamics, whereas Quaternary glacial cycles of forest change seem to have played a minor role in the origination of the currently recognized species.     

New species of Pachycotes Sharp and Xylechinus Chapuis (Coleoptera: Curculionidae: Scolytinae,Tomicini) from New Caledonian Araucaria spp. (Coniferales: Araucariaceae)

Abstract

Three new bark beetle species, Pachycotes grandis sp. n., P. engelsi sp. n., and Xylechinus araucariae sp. n. (Curculionidae, Scolytinae, Tomicini), are described and illustrated. Brief notes on their life histories are given. The beetles were collected from dead branches and logs of Araucaria laubenfelsii and A. muelleri trees in New Caledonia. In addition, a key for all nine known Pachycotes species (P. araucariae Schedl, P. australis Schedl, P. clavatus Schedl, P. grandis sp. n., P. engelsi sp. n., P. kuscheli Schedl, P. minor Wood, P. peregrinus (Chapuis), and P. villosus Schedl) is presented.     

Phylogeography and demography of Guianan harlequin toads (Atelopus): diversification within a refuge

We investigated the genetic structure of populations of Guianan harlequin toads (genus Atelopus) and their evolutionary affinities to extra-Guianan congeners. Phylogenetic analysis of mitochondrial cytochrome b (cyt b) and NADH dehydrogenase subunit 2 (ND2) gene sequences produced well-supported clades largely corresponding to the four recognized taxa in the Guianas (Atelopus spumarius hoogmoedi, Atelopus spumarius barbotini, Atelopus franciscus, and Atelopus flavescens). Our findings suggest that the Guianan A. spumarius represent distinct evolutionary lineages that merit distinction from Amazonian conspecifics, and that the status of A. flavescens and A. franciscus is somewhat less clear. Approximately 69% of the observed genetic variation is accounted for by differences between these four recognized taxa. Coalescent-based estimates of gene flow between taxa suggest that these lineages are largely isolated from one another. Negligible rates of migration between populations and significant divergence within such close proximity suggests that although the region inhabited by these taxa is almost entirely undisturbed, significant habitat heterogeneity exists as to have produced a remarkable diversification of Atelopus within the eastern Guiana Shield. These results contradict the commonly held view of the Guiana Shield as a 'refuge' whose stability during late Tertiary and Quaternary climatic fluctuations served as a biotic reservoir. Instead, we provide evidence that climatic fluctuations during this time had a diversifying effect within the Guianan region.     

Adaptive radiation within New Zealand endemic species of the cockroach genus Celatoblatta Johns (Blattidae): a response to Plio-Pleistocene mountain building and climate change

The South Island of New Zealand offers unique opportunities to study insect evolution due to long-term physical isolation, recent alpine habitats and high levels of biotic endemism. Using DNA sequence data from cytochrome oxidase subunit 1, we investigated the phylogeographical pattern among 10 endemic cockroach species within the genus Celatoblatta Johns (Blattidae). We tested the hypothesis that an ancestral cockroach species underwent rapid speciation in response to major climatic differentiation induced by mountain building. Results suggest that speciation was a twofold process, with an interspecific radiation of Pliocene/Pleistocene age followed by intraspecific diversification during the mid Pleistocene. Average genetic distance (maximum likelihood GTR + I + Gamma) was 9.17%, with a maximum of 14.5%. Data revealed eight deep well-supported branches, each with terminal clades. Six clades were differentiated according to morphological species, while the seventh was composed of three sympatric species. We consider the latter to be a phylogenetic species, possibly as a result of hybridization within a defined geographical area. This finding seriously challenges species distinctions for these three cockroach species. Correlation between genetic distances and a Climate Similarity Index (CSI) was negative, suggesting that species found in similar habitats are also genetically closely related. A Mantel test on within-clade genetic distances vs. linear geographical distance was positive, suggesting allopatric isolation for those haplotypes. We present a model of speciation for South Island Celatoblatta.     

Origin and post-colonization evolution of the Chatham Islands skink (Oligosoma nigriplantare nigriplantare)

Island ecosystems provide an opportunity to examine a range of evolutionary and ecological processes. The Chatham Islands are an isolated archipelago situated approximately 800 km east of New Zealand. Geological evidence indicates that the Chatham Islands re-emerged within the last 1-4 million years, following a prolonged period of marine inundation, and therefore the resident flora and fauna is the result of long-distance overwater dispersal. We examine the origin and post-colonization evolution of the Chatham Islands skink, Oligosoma nigriplantare nigriplantare, the sole reptile species occurring on the archipelago. We sampled O. n. nigriplantare from across nine islands within the Chatham Islands group, and representative samples from across the range of its closest relative, the New Zealand mainland common skink (Oligosoma nigriplantare polychroma). Our mitochondrial sequence data indicate that O. n. nigriplantare diverged from O. n. polychroma 5.86-7.29 million years ago. This pre-dates the emergence date for the Chatham Islands, but indicates that O. n. nigriplantare colonized the Chatham Islands via overwater dispersal on a single occasion. Despite the substantial morphological variability evident in O. n. nigriplantare, only relatively shallow genetic divergences (maximum divergence approximately 2%) were found across the Chatham Islands. Our analyses (haplotypic diversity, Phi(ST), analysis of molecular variance, and nested clade phylogeographical analysis) indicated restricted gene flow in O. n. nigriplantare resulting in strong differentiation between islands. However, the restrictions to gene flow might have only arisen recently as there was also a significant pattern of isolation by distance, possibly from when the Chatham Islands were a single landmass during Pleistocene glacial maxima when sea levels were lower. The level of genetic and morphological divergence between O. n. nigriplantare and O. n. polychroma might warrant their recognition as distinct species.     

Review of the New Caledonian species of Acritoptila Wells, 1982 (Trichoptera,Insecta), with descriptions of 3 new species

We review the New Caledonian representatives of the Australasian endemic hydroptiline genus Acritoptila, based on examination of a considerable collection of material in the Swedish Museum of Natural History and of types of previously established species. A key for identification of males is given and includes 3 species newly described here: A. parallelasp. n., A. forficatasp. n. and A. macrospinasp. n. For all New Caledonian species, male genitalia are illustrated, and for 5 associated females, distinctive features are illustrated and described.