Complex taxonomy of the 'brush tail' peregrine earthworm Pontoscolex corethrurus.

Pontoscolex corethrurus is the most widespread earthworm species in tropical and sub-tropical zones and one of the most studied in soil science. Although, ecological interactions of P. corethrurus with its environment are well documented, the taxonomic status of the species remains unclear. In this study, we investigated phylogenetic relationships within the genus Pontoscolex, in particular focusing on morphologically indistinguishable (i.e., cryptic) lineages. A total of 792 specimens collected from 25 different countries and islands all over the world were analyzed using two mitochondrial (COI and 16S rDNA) and two nuclear (internal transcribed spacers 2 and 28S rDNA) markers, and a total of 11 morphological characters both internal and external were investigated in all genetically characterized lineages. A large-scale multilocus sequence data matrix was also obtained for Pontoscolex spp. specimens using the Anchored Hybrid Enrichment (AHE) method. Multilocus phylogenetic and phylogenomic analyses, combined with species delimitation methods; including single locus (mPTP, ABGD) and multilocus (BPP) approaches, revealed congruent results. Four cryptic species were supported within the P. corethrurus species complex, and four potentially new species within the genus Pontoscolex. One widespread lineage (L1), within P. corethrurus complex was observed in the current population of Fritz Müller's garden where P. corethrurus was first described in 1856. Cryptic lineages were observed in sympatry at several localities. This, in combination with observed heteroplasmy in COI gene in one population raises an important question of reproductive isolation between these species.

Stay out (almost) all night: contrasting responses in flight activity among tropical moth assemblages.

Variations in diel activity among hyperdiverse tropical communities of moths, despite representing a key component of niche partitioning between species, have barely been studied so far. Using light trapping from dawn to sunset over a 1-year period in French Guiana, we investigated these variations within and between two families of moths (Sphingidae and Saturniidae). Our results revealed contrasting patterns in flight activity at night between Sphingidae and Saturniidae. Sphingidae reached their peak in species richness and abundance between 7:00 and 8:00 p.m., followed by a decrease around 11:00 p.m. to midnight, whereas Saturniidae were continuously present throughout the night, with a peak around midnight. In addition, we found changes in diel activity among some of the most common genera in each family, highlighting distinct behavioral, physiological, and functional traits among taxa. Given differences in flight activity at different taxonomic levels, it is strongly recommended to monitor by light trapping throughout the night to effectively sample saturniid and sphingid assemblages, even though the activity of Sphingidae sharply declines after midnight. These results improve the general natural history information of tropical moths and reinforce the need of further research on the ecological and taxonomic consequences of differences in diel activity.

DNA barcoding reveals a largely unknown fauna of Gracillariidae leaf-mining moths in the Neotropics.

Higher taxa often show increasing species richness towards tropical low latitudes, a pattern known as the latitudinal biodiversity gradient (LBG). A rare reverse LBG (with greater richness towards temperate high latitudes) is exhibited by Gracillariidae leaf-mining moths, in which most described species occur in northern temperate areas. We carried out the first assessment of gracillariid species diversity in two Neotropical regions to test whether the relatively low tropical species diversity of this family is genuine or caused by insufficient sampling and a strong taxonomic impediment. Field surveys in six French Guianan and one Ecuadorian site produced 516 gracillariid specimens that were DNA barcoded to facilitate identification and to match larvae inside leaf mines with adults. Species delineation from sequence data was approximated using Automatic Barcode Gap Discovery and Refined Single Linkage Analysis through the Barcode Index Number system, and the proportion of described/undescribed species was estimated after comparison with types of 83% of described species. Locally, alpha-diversity far exceeds that of any known temperate fauna, with as many as 108 candidate species (59.3% as singletons) collected at one site, and with an estimated species richness lower bound of 240 species. Strikingly, at least 85% of the species collected as adults were found to be undescribed. Our sampling represents the most thorough survey of gracillariid species diversity in the Neotropics to date and the results from both our molecular and morphological analyses indicate that the current reverse LBG seen in this group is an artefact of insufficient sampling and a strong description deficit in the Neotropics.

DNA barcoding and the taxonomy of Microgastrinae wasps (Hymenoptera, Braconidae): impacts after 8 years and nearly 20 000 sequences.

Microgastrine wasps are among the most species-rich and numerous parasitoids of caterpillars (Lepidoptera). They are often host-specific and thus are extensively used in biological control efforts and figure prominently in trophic webs. However, their extraordinary diversity coupled with the occurrence of many cryptic species produces a significant taxonomic impediment. We present and release the results of 8 years (2004-2011) of DNA barcoding microgastrine wasps. Currently they are the best represented group of parasitoid Hymenoptera in the Barcode of Life Data System (BOLD), a massive barcode storage and analysis data management site for the International Barcoding of Life (iBOL) program. There are records from more than 20 000 specimens from 75 countries, including 50 genera (90% of the known total) and more than 1700 species (as indicated by Barcode Index Numbers and 2% MOTU). We briefly discuss the importance of this DNA data set and its collateral information for future research in: (1) discovery of cryptic species and description of new taxa; (2) estimating species numbers in biodiversity inventories; (3) clarification of generic boundaries; (4) biological control programmes; (5) molecular studies of host-parasitoid biology and ecology; (6) evaluation of shifts in species distribution and phenology; and (7) fostering collaboration at national, regional and world levels. The integration of DNA barcoding with traditional morphology-based taxonomy, host records, and other data has substantially improved the accuracy of microgastrine wasp identifications and will significantly accelerate further studies on this group of parasitoids.

Re-integrating earthworm juveniles into soil biodiversity studies: species identification through DNA barcoding.

Species identification of earthworms is usually achieved by careful observation of morphological features, often sexual characters only present in adult specimens. Consequently, juveniles or cocoons are often impossible to identify, creating a possible bias in studies that aim to document species richness and abundance. DNA barcoding, the use of a short standardized DNA fragment for species identification, is a promising approach for species discrimination. When a reference library is available, DNA-based identification is possible for all life stages. In this study, we show that DNA barcoding is an unrivaled tool for high volume identification of juvenile earthworms. To illustrate this advance, we generated DNA barcodes for specimens of Lumbricus collected from three temperate grasslands in western France. The analysis of genetic distances between individuals shows that juvenile sequences unequivocally match DNA barcode clusters of previously identified adult specimens, demonstrating the potential of DNA barcoding to provide exhaustive specimen identification for soil ecological research.

Mitochondrial and microsatellite DNA markers reveal a Balkan origin for the highly invasive horse-chestnut leaf miner Cameraria ohridella (Lepidoptera, Gracillariidae).

Biological invasions usually start with a small number of founder individuals. These founders are likely to represent a small fraction of the total genetic diversity found in the source population. Our study set out to trace genetically the geographical origin of the horse-chestnut leafminer, Cameraria ohridella, an invasive microlepidopteran whose area of origin is still unkown. Since its discovery in Macedonia 25 years ago, this insect has experienced an explosive westward range expansion, progressively colonizing all of Central and Western Europe. We used cytochrome oxidase I sequences (DNA barcode fragment) and a set of six polymorphic microsatellites to assess the genetic variability of C. ohridella populations, and to test the hypothesis that C. ohridella derives from the southern Balkans (Albania, Macedonia and Greece). Analysis of mtDNA of 486 individuals from 88 localities allowed us to identify 25 geographically structured haplotypes. In addition, 480 individuals from 16 populations from Europe and the southern Balkans were genotyped for 6 polymorphic microsatellite loci. High haplotype diversity and low measures of nucleotide diversities including a significantly negative Tajima's D indicate that C. ohridella has experienced rapid population expansion during its dispersal across Europe. Both mtDNA and microsatellites show a reduction in genetic diversity of C. ohridella populations sampled from artificial habitats (e.g. planted trees in public parks, gardens, along roads in urban or sub-urban areas) across Europe compared with C. ohridella sampled in natural stands of horse-chestnuts in the southern Balkans. These findings suggest that European populations of C. ohridella may indeed derive from the southern Balkans.