Review of Apanteles sensu stricto (Hymenoptera, Braconidae, Microgastrinae) from Area de Conservación Guanacaste, northwestern Costa Rica, with keys to all described species from Mesoamerica

More than half a million specimens of wild-caught Lepidoptera caterpillars have been reared for their parasitoids, identified, and DNA barcoded over a period of 34 years (and ongoing) from Area de Conservación de Guanacaste (ACG), northwestern Costa Rica. This provides the world's best location-based dataset for studying the taxonomy and host relationships of caterpillar parasitoids. Among Hymenoptera, Microgastrinae (Braconidae) is the most diverse and commonly encountered parasitoid subfamily, with many hundreds of species delineated to date, almost all undescribed. Here, we reassess the limits of the genus Apanteles sensu stricto, describe 186 new species from 3,200+ parasitized caterpillars of hundreds of ACG Lepidoptera species, and provide keys to all 205 described Apanteles from Mesoamerica - including 19 previously described species in addition to the new species. The Mesoamerican Apanteles are assigned to 32 species-groups, all but two of which are newly defined. Taxonomic keys are presented in two formats: traditional dichotomous print versions and links to electronic interactive versions (software Lucid 3.5). Numerous illustrations, computer-generated descriptions, distributional information, wasp biology, and DNA barcodes (where available) are presented for every species. All morphological terms are detailed and linked to the Hymenoptera Anatomy Ontology website. DNA barcodes (a standard fragment of the cytochrome c oxidase I (COI) mitochondrial gene), information on wasp biology (host records, solitary/gregariousness of wasp larvae), ratios of morphological features, and wasp microecological distributions were used to help clarify boundaries between morphologically cryptic species within species-complexes. Because of the high accuracy of host identification for about 80% of the wasp species studied, it was possible to analyze host relationships at a regional level. The ACG species of Apanteles attack mainly species of Hesperiidae, Elachistidae and Crambidae (Lepidoptera). About 90% of the wasp species with known host records seem to be monophagous or oligophagous at some level, parasitizing just one host family and commonly, just one species of caterpillar. Only 15 species (9%) parasitize species in more than one family, and some of these cases are likely to be found to be species complexes. We have used several information sources and techniques (traditional taxonomy, molecular, software-based, biology, and geography) to accelerate the process of finding and describing these new species in a hyperdiverse group such as Apanteles. The following new taxonomic and nomenclatural acts are proposed. Four species previously considered to be Apanteles are transferred to other microgastrine genera: Dolichogenidea hedyleptae (Muesebeck, 1958), comb. n., Dolichogenidea politiventris (Muesebeck, 1958), comb. n., Rhygoplitis sanctivincenti (Ashmead, 1900), comb. n., and Illidops scutellaris (Muesebeck, 1921), comb. rev. One European species that is a secondary homonym to a Mesoamerican species is removed from Apanteles and transferred to another genus: Iconella albinervis (Tobias, 1964), stat. rev. The name Apanteles albinervican Shenefelt, 1972, is an invalid replacement name for Apanteles albinervis (Cameron, 1904), stat. rev., and thus the later name is reinstated as valid. The following 186 species, all in Apanteles and all authored by Fernández-Triana, are described as species nova: adelinamoralesae, adrianachavarriae, adrianaguilarae, adrianguadamuzi, aichagirardae, aidalopezae, albanjimenezi, alejandromasisi, alejandromorai, minorcarmonai, alvarougaldei, federicomatarritai, anabellecordobae, rostermoragai, anamarencoae, anamartinesae, anapiedrae, anariasae, andreacalvoae, angelsolisi, arielopezi, bernardoespinozai, bernyapui, bettymarchenae, bienvenidachavarriae, calixtomoragai, carloscastilloi, carlosguadamuzi, eliethcantillanoae, carlosrodriguezi, carlosviquezi, carloszunigai, carolinacanoae, christianzunigai, cinthiabarrantesae, ciriloumanai, cristianalemani, cynthiacorderoae, deifiliadavilae, dickyui, didiguadamuzi, diegoalpizari, diegotorresi, diniamartinezae, duniagarciae, duvalierbricenoi, edgarjimenezi, edithlopezae, eduardoramirezi, edwinapui, eldarayae, erickduartei, esthercentenoae, eugeniaphilipsae, eulogiosequeira, felipechavarriai, felixcarmonai, fernandochavarriai, flormoralesae, franciscopizarroi, franciscoramirezi, freddyquesadai, freddysalazari, gabrielagutierrezae, garygibsoni, gerardobandoi, gerardosandovali, gladysrojasae, glenriverai, gloriasihezarae, guadaluperodriguezae, guillermopereirai, juanmatai, harryramirezi, hectorsolisi, humbertolopezi, inesolisae, irenecarrilloae, isaacbermudezi, isidrochaconi, isidrovillegasi, ivonnetranae, jairomoyai, javiercontrerasi, javierobandoi, javiersihezari, jesusbrenesi, jesusugaldei, jimmychevezi, johanvargasi, jorgecortesi, jorgehernandezi, josecalvoi, josecortesi, josediazi, josejaramilloi, josemonteroi, joseperezi, joserasi, juanapui, juancarrilloi, juangazoi, juanhernandezi, juanlopezi, juanvictori, juliodiazi, juniorlopezi, keineraragoni, laurahuberae, laurenmoralesae, leninguadamuzi, leonelgarayi, lilliammenae, lisabearssae, luciariosae, luisbrizuelai, luiscanalesi, luiscantillanoi, luisgarciai, luisgaritai, luishernandezi, luislopezi, luisvargasi, manuelarayai, manuelpereirai, manuelriosi, manuelzumbadoi, marcobustosi, marcogonzalezi, marcovenicioi, mariachavarriae mariaguevarae, marialuisariasae, mariamendezae, marianopereirai, mariatorrentesae, sigifredomarini, marisolarroyoae, marisolnavarroae, marvinmendozai, mauriciogurdiani, milenagutierrezae, monicachavarriae, oscarchavesi, osvaldoespinozai, pablotranai, pabloumanai, pablovasquezi, paulaixcamparijae, luzmariaromeroae, petronariosae, randallgarciai, randallmartinezi, raulacevedoi, raulsolorsanoi, wadyobandoi, ricardocaleroi, robertmontanoi, robertoespinozai, robertovargasi, rodrigogamezi, rogerblancoi, rolandoramosi, rolandovegai, ronaldcastroi, ronaldgutierrezi, ronaldmurilloi, ronaldnavarroi, ronaldquirosi, ronaldzunigai, rosibelelizondoae, ruthfrancoae, sergiocascantei, sergioriosi, tiboshartae, vannesabrenesae, minornavarroi, victorbarrantesi, waldymedinai, wilbertharayai, williamcamposi, yeissonchavesi, yilbertalvaradoi, yolandarojasae, hazelcambroneroae, zeneidabolanosae.

Recovery of DNA barcodes from blackfly museum specimens (Diptera: Simuliidae) using primer sets that target a variety of sequence lengths

In this study, we evaluated the efficacy of various primers for the purpose of DNA barcoding old, pinned museum specimens of blackflies (Diptera: Simuliidae). We analysed 271 pinned specimens representing two genera and at least 36 species. Due to the age of our material, we targeted overlapping DNA fragments ranging in size from 94 to 407 bp. We were able to recover valid sequences from 215 specimens, of which 18% had 500- to 658-bp barcodes, 36% had 201- to 499-bp barcodes and 46% had 65- to 200-bp barcodes. Our study demonstrates the importance of choosing suitable primers when dealing with older specimens and shows that even very short sequences can be diagnostically informative provided that an appropriate gene region is used. Our study also highlights the lack of knowledge surrounding blackfly taxonomy, and we briefly discuss the need for further phylogenetic studies in this socioeconomically important family of insects.

Genetic patterns in European geometrid moths revealed by the Barcode Index Number (BIN) system

Background

The geometrid moths of Europe are one of the best investigated insect groups in traditional taxonomy making them an ideal model group to test the accuracy of the Barcode Index Number (BIN) system of BOLD (Barcode of Life Datasystems), a method that supports automated, rapid species delineation and identification.

Methodology/Principal Findings

This study provides a DNA barcode library for 219 of the 249 European geometrid moth species (88%) in five selected subfamilies. The data set includes COI sequences for 2130 specimens. Most species (93%) were found to possess diagnostic barcode sequences at the European level while only three species pairs (3%) were genetically indistinguishable in areas of sympatry. As a consequence, 97% of the European species we examined were unequivocally discriminated by barcodes within their natural areas of distribution. We found a 1:1 correspondence between BINs and traditionally recognized species for 67% of these species. Another 17% of the species (15 pairs, three triads) shared BINs, while specimens from the remaining species (18%) were divided among two or more BINs. Five of these species are mixtures, both sharing and splitting BINs. For 82% of the species with two or more BINs, the genetic splits involved allopatric populations, many of which have previously been hypothesized to represent distinct species or subspecies.

Conclusions/Significance

This study confirms the effectiveness of DNA barcoding as a tool for species identification and illustrates the potential of the BIN system to characterize formal genetic units independently of an existing classification. This suggests the system can be used to efficiently assess the biodiversity of large, poorly known assemblages of organisms. For the moths examined in this study, cases of discordance between traditionally recognized species and BINs arose from several causes including overlooked species, synonymy, and cases where DNA barcodes revealed regional variation of uncertain taxonomic significance.

Shared but overlooked: 30 species of Holarctic Microlepidoptera revealed by DNA barcodes and morphology

This study reports 30 species of Lepidoptera previously known from either the Palearctic or the Nearctic that are newly recorded as Holarctic. For 28 of these species, their intercontinental distributions were initially detected through DNA barcode analysis and subsequently confirmed by morphological examination; two Palearctic species were first detected in North America through morphology and then barcoded. When possible, the origin and status of each species (introduced, overlooked Holarctic species, or unknowingly re-described) is discussed, and its morphology is diagnosed and illustrated. The species involved include Tineidae: Scardia amurensis Zagulajev, Triaxomera parasitella (Hübner), Nemapogon cloacella (Haworth), Elatobia montelliella (Schantz), Tinea svenssoni Opheim; Gracillariidae: Caloptilia suberinella (Tengström), Parornix betulae (Stainton); Phyllonorycter maestingella (Müller); Yponomeutidae: Paraswammerdamia albicapitella (Scharfenberg), P. conspersella (Tengström); Plutellidae: Plutella hyperboreella Strand; Lyonetiidae: Lyonetia pulverulentella Zeller; Autostichidae: Oegoconia deauratella (Herrich-Schäffer), O. novimundi (Busck); Blastobasidae: Blastobasis glandulella (Riley), B. maroccanella (Amsel), B. tarda Meyrick; Depressariidae: Agonopterix conterminella (Zeller), Depressaria depressana (F.); Coleophoridae: Coleophora atriplicis Meyrick, C. glitzella Hofmann, C. granulatella Zeller, C. texanella Chambers, C. vitisella Gregson; Scythrididae: Scythris sinensis (Felder & Rogenhofer); Gelechiidae: Altenia perspersella (Wocke), Gnorimoschema jalavai Povolný, Scrobipalpa acuminatella (Sircom), Sophronia gelidella Nordman; Choreutidae: Anthophila fabriciana (L.); and Tortricidae: Phiaris bipunctana (F.). These cases of previously unrecognized faunal overlap have led to their redescription in several instances. Five new synonyms are proposed: Blastobasis glandulella (Riley, 1871) = B. huemeri Sinev, 1993, syn. nov.; B. tarda Meyrick, 1902 = Neoblastobasis ligurica Nel & Varenne, 2004, syn. nov.; Coleophora atriplicis Meyrick, 1928 = C. cervinella McDunnough, 1946, syn. nov.; C. texanella Chambers, 1878 = C. coxi Baldizzone & van der Wolf, 2007, syn. nov., and = C. vagans Walsingham, 1907, syn. nov. Lectotypes are designated for Blastobasis tarda Meyrick and Coleophora texanella Chambers. Type specimens were examined where pertinent to establish new synonymies. We identify 12 previously overlooked cases of species introductions, highlighting the power of DNA barcoding as a tool for biosurveillance.

Spiders (Araneae) of Churchill, Manitoba: DNA barcodes and morphology reveal high species diversity and new Canadian records

BACKGROUND

Arctic ecosystems, especially those near transition zones, are expected to be strongly impacted by climate change. Because it is positioned on the ecotone between tundra and boreal forest, the Churchill area is a strategic locality for the analysis of shifts in faunal composition. This fact has motivated the effort to develop a comprehensive biodiversity inventory for the Churchill region by coupling DNA barcoding with morphological studies. The present study represents one element of this effort; it focuses on analysis of the spider fauna at Churchill.

RESULTS

198 species were detected among 2704 spiders analyzed, tripling the count for the Churchill region. Estimates of overall diversity suggest that another 10-20 species await detection. Most species displayed little intraspecific sequence variation (maximum <1%) in the barcode region of the cytochrome c oxidase subunit I (COI) gene, but four species showed considerably higher values (maximum = 4.1-6.2%), suggesting cryptic species. All recognized species possessed a distinct haplotype array at COI with nearest-neighbour interspecific distances averaging 8.57%. Three species new to Canada were detected: Robertus lyrifer (Theridiidae), Baryphyma trifrons (Linyphiidae), and Satilatlas monticola (Linyphiidae). The first two species may represent human-mediated introductions linked to the port in Churchill, but the other species represents a range extension from the USA. The first description of the female of S. monticola was also presented. As well, one probable new species of Alopecosa (Lycosidae) was recognized.

CONCLUSIONS

This study provides the first comprehensive DNA barcode reference library for the spider fauna of any region. Few cryptic species of spiders were detected, a result contrasting with the prevalence of undescribed species in several other terrestrial arthropod groups at Churchill. Because most (97.5%) sequence clusters at COI corresponded with a named taxon, DNA barcoding reliably identifies spiders in the Churchill fauna. The capacity of DNA barcoding to enable the identification of otherwise taxonomically ambiguous specimens (juveniles, females) also represents a major advance for future monitoring efforts on this group.

DNA barcode identification of freshwater snails in the family Bithyniidae from Thailand

Freshwater snails in the family Bithyniidae are the first intermediate host for Southeast Asian liver fluke (Opisthorchis viverrini), the causative agent of opisthorchiasis. Unfortunately, the subtle morphological characters that differentiate species in this group are not easily discerned by non-specialists. This is a serious matter because the identification of bithyniid species is a fundamental prerequisite for better understanding of the epidemiology of this disease. Because DNA barcoding, the analysis of sequence diversity in the 5’ region of the mitochondrial COI gene, has shown strong performance in other taxonomic groups, we decided to test its capacity to resolve 10 species/ subspecies of bithyniids from Thailand. Our analysis of 217 specimens indicated that COI sequences delivered species-level identification for 9 of 10 currently recognized species. The mean intraspecific divergence of COI was 2.3% (range 0-9.2 %), whereas sequence divergences between congeneric species averaged 8.7% (range 0-22.2 %). Although our results indicate that DNA barcoding can differentiate species of these medically-important snails, we also detected evidence for the presence of one overlooked species and one possible case of synonymy.

Integration of DNA barcoding into an ongoing inventory of complex tropical biodiversity

Inventory of the caterpillars, their food plants and parasitoids began in 1978 for today's Area de Conservacion Guanacaste (ACG), in northwestern Costa Rica. This complex mosaic of 120 000 ha of conserved and regenerating dry, cloud and rain forest over 0-2000 m elevation contains at least 10 000 species of non-leaf-mining caterpillars used by more than 5000 species of parasitoids. Several hundred thousand specimens of ACG-reared adult Lepidoptera and parasitoids have been intensively and extensively studied morphologically by many taxonomists, including most of the co-authors. DNA barcoding - the use of a standardized short mitochondrial DNA sequence to identify specimens and flush out undisclosed species - was added to the taxonomic identification process in 2003. Barcoding has been found to be extremely accurate during the identification of about 100 000 specimens of about 3500 morphologically defined species of adult moths, butterflies, tachinid flies, and parasitoid wasps. Less than 1% of the species have such similar barcodes that a molecularly based taxonomic identification is impossible. No specimen with a full barcode was misidentified when its barcode was compared with the barcode library. Also as expected from early trials, barcoding a series from all morphologically defined species, and correlating the morphological, ecological and barcode traits, has revealed many hundreds of overlooked presumptive species. Many but not all of these cryptic species can now be distinguished by subtle morphological and/or ecological traits previously ascribed to 'variation' or thought to be insignificant for species-level recognition. Adding DNA barcoding to the inventory has substantially improved the quality and depth of the inventory, and greatly multiplied the number of situations requiring further taxonomic work for resolution.

A DNA 'barcode blitz': rapid digitization and sequencing of a natural history collection

DNA barcoding protocols require the linkage of each sequence record to a voucher specimen that has, whenever possible, been authoritatively identified. Natural history collections would seem an ideal resource for barcode library construction, but they have never seen large-scale analysis because of concerns linked to DNA degradation. The present study examines the strength of this barrier, carrying out a comprehensive analysis of moth and butterfly (Lepidoptera) species in the Australian National Insect Collection. Protocols were developed that enabled tissue samples, specimen data, and images to be assembled rapidly. Using these methods, a five-person team processed 41,650 specimens representing 12,699 species in 14 weeks. Subsequent molecular analysis took about six months, reflecting the need for multiple rounds of PCR as sequence recovery was impacted by age, body size, and collection protocols. Despite these variables and the fact that specimens averaged 30.4 years old, barcode records were obtained from 86% of the species. In fact, one or more barcode compliant sequences (>487 bp) were recovered from virtually all species represented by five or more individuals, even when the youngest was 50 years old. By assembling specimen images, distributional data, and DNA barcode sequences on a web-accessible informatics platform, this study has greatly advanced accessibility to information on thousands of species. Moreover, much of the specimen data became publically accessible within days of its acquisition, while most sequence results saw release within three months. As such, this study reveals the speed with which DNA barcode workflows can mobilize biodiversity data, often providing the first web-accessible information for a species. These results further suggest that existing collections can enable the rapid development of a comprehensive DNA barcode library for the most diverse compartment of terrestrial biodiversity – insects.

A DNA-based registry for all animal species: the barcode index number (BIN) system

Because many animal species are undescribed, and because the identification of known species is often difficult, interim taxonomic nomenclature has often been used in biodiversity analysis. By assigning individuals to presumptive species, called operational taxonomic units (OTUs), these systems speed investigations into the patterning of biodiversity and enable studies that would otherwise be impossible. Although OTUs have conventionally been separated through their morphological divergence, DNA-based delineations are not only feasible, but have important advantages. OTU designation can be automated, data can be readily archived, and results can be easily compared among investigations. This study exploits these attributes to develop a persistent, species-level taxonomic registry for the animal kingdom based on the analysis of patterns of nucleotide variation in the barcode region of the cytochrome c oxidase I (COI) gene. It begins by examining the correspondence between groups of specimens identified to a species through prior taxonomic work and those inferred from the analysis of COI sequence variation using one new (RESL) and four established (ABGD, CROP, GMYC, jMOTU) algorithms. It subsequently describes the implementation, and structural attributes of the Barcode Index Number (BIN) system. Aside from a pragmatic role in biodiversity assessments, BINs will aid revisionary taxonomy by flagging possible cases of synonymy, and by collating geographical information, descriptive metadata, and images for specimens that are likely to belong to the same species, even if it is undescribed. More than 274,000 BIN web pages are now available, creating a biodiversity resource that is positioned for rapid growth.

DNA barcoding a regional bee (Hymenoptera: Apoidea) fauna and its potential for ecological studies

DNA barcoding has been evaluated for many animal taxa and is now advocated as a reliable and rapid means for species-level identification. The coming-to-light of this identification tool is timely as we are now facing perhaps the greatest rate of species loss in recent millennia. This study contributes to an ever-increasing number of published accounts of DNA barcoding successfully and accurately distinguishing animal taxa, in this instance, the bee fauna of Nova Scotia, Canada. Most members of this well-known fauna were resolved with particular clarity; the average intraspecific divergence was less than 0.5%, and COI sequences from over 75% of the province's species are now in the Barcodes of Life Data System. DNA barcoding also revealed some surprises within this fauna, including the possible recognition of two undescribed genetically unique species, one in the genus Ceratina (subgenus Zadontomerus), the second in the genus Andrena (subgenus Larandrena); both are presently receiving further taxonomic study. In addition, DNA barcoding has allowed sex-associations among two pairs of cleptoparasitic species. The resulting utility of DNA barcoding for ecological studies of bee communities is discussed.

The front-end logistics of DNA barcoding: challenges and prospects

Building a global library of DNA barcodes will require efficient logistics of pre-laboratory specimen processing and seamless interfacing with molecular protocols. If not addressed properly, the task of aggregating specimens may become the biggest bottleneck in the analytical chain. Three years of experience in developing a collection management system to facilitate high-throughput DNA barcoding have allowed the Canadian Centre for DNA Barcoding to recognize and resolve the most common logistical obstacles. Dealing with these challenges on a larger scale will be an important step towards building a solid collection-based foundation for the international DNA barcoding effort.

Species identification of aphids (Insecta: Hemiptera: Aphididae) through DNA barcodes

A 658-bp fragment of mitochondrial DNA from the 5' region of the mitochondrial cytochrome c oxidase 1 (COI) gene has been adopted as the standard DNA barcode region for animal life. In this study, we test its effectiveness in the discrimination of over 300 species of aphids from more than 130 genera. Most (96%) species were well differentiated, and sequence variation within species was low, averaging just 0.2%. Despite the complex life cycles and parthenogenetic reproduction of aphids, DNA barcodes are an effective tool for identification.

DNA barcode accumulation curves for understudied taxa and areas

Frequently, the diversity of umbrella taxa is invoked to predict patterns of other, less well-known, life. However, the utility of this strategy has been questioned. We tested whether a phylogenetic diversity (PD) analysis of CO1 DNA barcodes could act as a proxy for standard methods of determining sampling efficiency within and between sites, namely that an accumulation curve of barcode diversity would be similar to curves generated using morphology or nuclear genetic markers. Using taxa at the forefront of the taxonomic impediment - parasitoid wasps (Ichneumonidae, Braconidae, Cynipidae and Diapriidae), contrasted with a taxon expected to be of low diversity (Formicidae) from an area where total diversity is expected to be low (Churchill, Manitoba), we found that barcode accumulation curves based on PD were significantly different in both slope and scale from curves generated using names based on morphological data, while curves generated using nuclear genetic data were only different in scale. We conclude that these differences clearly identify the taxonomic impediment within the strictly morphological alpha-taxonomy of these hyperdiverse insects. The absence of an asymptote within the barcode PD trend of parasitoid wasps reflects the as yet incomplete sampling of the site (and more accurately its total diversity), while the morphological analysis asymptote represents a collision with the taxonomic impediment rather than complete sampling. We conclude that a PD analysis of standardized DNA barcodes can be a transparent and reproducible triage tool for the management and conservation of species and spaces.

DNA barcode analysis of butterfly species from Pakistan points towards regional endemism

DNA barcodes were obtained for 81 butterfly species belonging to 52 genera from sites in north-central Pakistan to test the utility of barcoding for their identification and to gain a better understanding of regional barcode variation. These species represent 25% of the butterfly fauna of Pakistan and belong to five families, although the Nymphalidae were dominant, comprising 38% of the total specimens. Barcode analysis showed that maximum conspecific divergence was 1.6%, while there was 1.7–14.3% divergence from the nearest neighbour species. Barcode records for 55 species showed <2% sequence divergence to records in the Barcode of Life Data Systems (BOLD), but only 26 of these cases involved specimens from neighbouring India and Central Asia. Analysis revealed that most species showed little incremental sequence variation when specimens from other regions were considered, but a threefold increase was noted in a few cases. There was a clear gap between maximum intraspecific and minimum nearest neighbour distance for all 81 species. Neighbour-joining cluster analysis showed that members of each species formed a monophyletic cluster with strong bootstrap support. The barcode results revealed two provisional species that could not be clearly linked to known taxa, while 24 other species gained their first coverage. Future work should extend the barcode reference library to include all butterfly species from Pakistan as well as neighbouring countries to gain a better understanding of regional variation in barcode sequences in this topographically and climatically complex region.

Advancing nematode barcoding: a primer cocktail for the cytochrome c oxidase subunit I gene from vertebrate parasitic nematodes

Although nematodes are one of the most diverse metazoan phyla, species identification through morphology is difficult. Several genetic markers have been used for their identification, but most do not provide species-level resolution in all groups, and those that do lack primer sets effective across the phylum, precluding high-throughput processing. This study describes a cocktail of three novel primer pairs that overcome this limitation by recovering cytochrome c oxidase I (COI) barcodes from diverse nematode lineages parasitic on vertebrates, including members of three orders and eight families. Its effectiveness across a broad range of nematodes enables high-throughput processing.

Diversification and reproductive isolation: cryptic species in the only New World high-duty cycle bat, Pteronotus parnellii

BACKGROUND

Molecular techniques are increasingly employed to recognize the presence of cryptic species, even among commonly observed taxa. Previous studies have demonstrated that bats using high-duty cycle echolocation may be more likely to speciate quickly. Pteronotus parnellii is a widespread Neotropical bat and the only New World species to use high-duty cycle echolocation, a trait otherwise restricted to Old World taxa. Here we analyze morphological and acoustic variation and genetic divergence at the mitochondrial COI gene, the 7th intron region of the y-linked Dby gene and the nuclear recombination-activating gene 2, and provide extensive evidence that P. parnellii is actually a cryptic species complex.

RESULTS

Central American populations form a single species while three additional species exist in northern South America: one in Venezuela, Trinidad and western Guyana and two occupying sympatric ranges in Guyana and Suriname. Reproductive isolation appears nearly complete (only one potential hybrid individual found). The complex likely arose within the last ~6 million years with all taxa diverging quickly within the last ~1-2 million years, following a pattern consistent with the geological history of Central and northern South America. Significant variation in cranial measures and forearm length exists between three of the four groups, although no individual morphological character can discriminate these in the field. Acoustic analysis reveals small differences (5-10 kHz) in echolocation calls between allopatric cryptic taxa that are unlikely to provide access to different prey resources but are consistent with divergence by drift in allopatric species or through selection for social recognition.

CONCLUSIONS

This unique approach, considering morphological, acoustic and multi-locus genetic information inherited maternally, paternally and bi-parentally, provides strong support to conclusions about the cessation of gene flow and degree of reproductive isolation of these cryptic species.

DNA barcoding reveals diversity of Hymenoptera and the dominance of parasitoids in a sub-arctic environment

Background

Insect diversity typically declines with increasing latitude, but previous studies have shown conflicting latitude-richness gradients for some hymenopteran parasitoids. However, historical estimates of insect diversity and species richness can be difficult to confirm or compare, because they may be based upon dissimilar methods. As a proxy for species identification, we used DNA barcoding to identify molecular operational taxonomic units (MOTUs) for 7870 Hymenoptera specimens collected near Churchill, Manitoba, from 2004 through 2010.

Results

We resolved 1630 MOTUs for this collection, of which 75% (1228) were ichneumonoids (Ichneumonidae + Braconidae) and 91% (1484) were parasitoids. We estimate the total number of Hymenoptera MOTUs in this region at 2624-2840.

Conclusions

The diversity of parasitoids in this sub-Arctic environment implies a high diversity of potential host species throughout the same range. We discuss these results in the contexts of resolving interspecific interactions that may include cryptic species, and developing reproducible methods to estimate and compare species richness across sites and between surveys, especially when morphological specialists are not available to identify every specimen.

Species-specific primers designed from RAPD products for Bithynia funiculata, the first intermediate host of liver fluke, Opisthorchis viverrini, in North Thailand

Bithynia funiculata is the first intermediate host of the human liver fluke Opisthorchis viverrini in northern Thailand but its identification through morphological analysis is often problematic due to the shortage of gastropod taxonomists. As a consequence, we focused on the development of species-specific primers for use as an identification tool. Our work involved recovery of a 502-base pair (bp) amplicon of unknown function through species-specific primers whose effectiveness was tested by analyzing specimens of B. funiculata from 3 locations in northern Thailand. This primer set did not amplify other species in the Bithyniidae or in other gastropod families. By providing a tool to confirm morphological identifications of B. funiculata, and by enabling the identification of juvenile specimens and those with damaged shells, these primers will improve estimates of the prevalence of parasitic infections in this snail.

Revealing the hyperdiverse mite fauna of subarctic Canada through DNA barcoding

Although mites are one of the most abundant and diverse groups of arthropods, they are rarely targeted for detailed biodiversity surveys due to taxonomic constraints. We address this gap through DNA barcoding, evaluating acarine diversity at Churchill, Manitoba, a site on the tundra-taiga transition. Barcode analysis of 6279 specimens revealed nearly 900 presumptive species of mites with high species turnover between substrates and between forested and non-forested sites. Accumulation curves have not reached an asymptote for any of the three mite orders investigated, and estimates suggest that more than 1200 species of Acari occur at this locality. The coupling of DNA barcode results with taxonomic assignments revealed that Trombidiformes compose 49% of the fauna, a larger fraction than expected based on prior studies. This investigation demonstrates the efficacy of DNA barcoding in facilitating biodiversity assessments of hyperdiverse taxa.

Allopatry as a gordian knot for taxonomists: patterns of DNA barcode divergence in arctic-alpine lepidoptera

Many cold adapted species occur in both montane settings and in the subarctic. Their disjunct distributions create taxonomic complexity because there is no standardized method to establish whether their allopatric populations represent single or different species. This study employs DNA barcoding to gain new perspectives on the levels and patterns of sequence divergence among populations of 122 arctic-alpine species of Lepidoptera from the Alps, Fennoscandia and North America. It reveals intraspecific variability in the barcode region ranging from 0.00-10.08%. Eleven supposedly different species pairs or groups show close genetic similarity, suggesting possible synonymy in many cases. However, a total of 33 species show evidence of cryptic diversity as evidenced by the presence of lineages with over 2% maximum barcode divergence in Europe, in North America or between the two continents. Our study also reveals cases where taxonomic names have been used inconsistently between regions and exposes misidentifications. Overall, DNA barcodes have great potential to both increase taxonomic resolution and to make decisions concerning the taxonomic status of allopatric populations more objective.

A DNA barcode library for North American Ephemeroptera: progress and prospects

DNA barcoding of aquatic macroinvertebrates holds much promise as a tool for taxonomic research and for providing the reliable identifications needed for water quality assessment programs. A prerequisite for identification using barcodes is a reliable reference library. We gathered 4165 sequences from the barcode region of the mitochondrial cytochrome c oxidase subunit I gene representing 264 nominal and 90 provisional species of mayflies (Insecta: Ephemeroptera) from Canada, Mexico, and the United States. No species shared barcode sequences and all can be identified with barcodes with the possible exception of some Caenis. Minimum interspecific distances ranged from 0.3–24.7% (mean: 12.5%), while the average intraspecific divergence was 1.97%. The latter value was inflated by the presence of very high divergences in some taxa. In fact, nearly 20% of the species included two or three haplotype clusters showing greater than 5.0% sequence divergence and some values are as high as 26.7%. Many of the species with high divergences are polyphyletic and likely represent species complexes. Indeed, many of these polyphyletic species have numerous synonyms and individuals in some barcode clusters show morphological attributes characteristic of the synonymized species. In light of our findings, it is imperative that type or topotype specimens be sequenced to correctly associate barcode clusters with morphological species concepts and to determine the status of currently synonymized species.