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1.
Mol Phylogenet Evol ; 184: 107778, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37030415

RESUMO

Leaf-mining flies (Diptera: Agromyzidae) are a diverse clade of phytophagous Diptera known largely for their economic impact as leaf- or stem-miners on vegetable and ornamental plants. Higher-level phylogenetic relationships of Agromyzidae have remained uncertain because of challenges in sampling of both taxa and characters for morphology and PCR-based Sanger-era molecular systematics. Here, we used hundreds of orthologous single-copy nuclear loci obtained from anchored hybrid enrichment (AHE) to reconstruct phylogenetic relationships among the major lineages of leaf-mining flies. The resulting phylogenetic trees are highly congruent and well-supported, except for a few deep nodes, when using different molecular data types and phylogenetic methods. Based on divergence time dating using a relaxed clock model-based analysis, leaf-mining flies are shown to have diversified in multiple lineages since the early Paleocene, approximately 65 million years ago. Our study not only reveals a revised classification system of leaf-mining flies, but also provides a new phylogenetic framework to understand their macroevolution.


Assuntos
Dípteros , Filogenia , Genômica , Dípteros/genética , Animais , Funções Verossimilhança , Loci Gênicos
2.
Mol Ecol Resour ; 21(7): 2437-2454, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34051038

RESUMO

Molecular identification is increasingly used to speed up biodiversity surveys and laboratory experiments. However, many groups of organisms cannot be reliably identified using standard databases such as GenBank or BOLD due to lack of sequenced voucher specimens identified by experts. Sometimes a large number of sequences are available, but with too many errors to allow identification. Here, we address this problem for parasitoids of Drosophila by introducing a curated open-access molecular reference database, DROP (Drosophila parasitoids). Identifying Drosophila parasitoids is challenging and poses a major impediment to realize the full potential of this model system in studies ranging from molecular mechanisms to food webs, and in biological control of Drosophila suzukii. In DROP, genetic data are linked to voucher specimens and, where possible, the voucher specimens are identified by taxonomists and vetted through direct comparison with primary type material. To initiate DROP, we curated 154 laboratory strains, 856 vouchers, 554 DNA sequences, 16 genomes, 14 transcriptomes, and six proteomes drawn from a total of 183 operational taxonomic units (OTUs): 114 described Drosophila parasitoid species and 69 provisional species. We found species richness of Drosophila parasitoids to be heavily underestimated and provide an updated taxonomic catalogue for the community. DROP offers accurate molecular identification and improves cross-referencing between individual studies that we hope will catalyse research on this diverse and fascinating model system. Our effort should also serve as an example for researchers facing similar molecular identification problems in other groups of organisms.


Assuntos
Biodiversidade , Drosophila , Animais , Drosophila/genética , Cadeia Alimentar
3.
Zootaxa ; 4450(1): 77-90, 2018 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-30313858

RESUMO

Leafmining Agromyzidae (Diptera) are both common and widespread, yet little is known of the host associations and distribution of most species. Here we report on a multi-year study of agromyzid diversity on Long Island, New York. We reared 45 species and identified for the first time a host plant for Agromyza masculina Sehgal and a likely host plant for Ophiomyia carolinensis Spencer. Of the 45 species, 17 are new records for New York State, for which fewer than 40 agromyzid species had previously been known. A new agromyzid species was reared from blotch mines on black-eyed Susan, Rudbeckia sp. and an undetermined yellow garden composite, both in the Asteraceae; this species is described here.


Assuntos
Asteraceae , Dípteros , Animais , New York
4.
Zootaxa ; 4399(1): 1-31, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-29690327

RESUMO

Five new species of Fergusobia are described. Fergusobia janetae Davies n. sp. is characterized by the combination of an arcuate to straight, spindle-shaped parthenogenetic female with a relatively small oesophageal gland, an extensile uterus and a conoid tail, an arcuate infective female with a bluntly rounded tail tip, and a C-shaped male with an arcuate to angular spicule and bursa arising at more than 90% of body length. Fergusobia robustae Davies n. sp. is characterized by the combination of a small, C-shaped parthenogenetic female with a short cylindroid tail with a broadly rounded tip; an arcuate to C-shaped, relatively broad, infective female with a tail tip that is almost hemispherical; and an arcuate male with a strong angular spicule and a bursa arising at 30-40% of body length. Fergusobia pruinosae Davies n. sp. is characterized by the combination of a medium sized, open C-shaped, parthenogenetic female in which the cuticle does not swell upon fixation, with a strongly sclerotised stylet, with a more or less narrowly conoid tail with a bluntly or broadly rounded tip; infective female that is arcuate to J-shaped with a notched tail tip; and open C-shaped males with stout, angular spicules and bursa arising near the secretory/excretory pore. Fergusobia pauciflorae Davies n. sp. is characterized by the combination of a medium sized, arcuate, parthenogenetic female with a small stylet, and a conoid tail with a bluntly rounded tip; a small, open C to J-shaped infective female with a broadly rounded to almost hemispherical tail tip; and straight to arcuate males with stout, angular spicules and bursa at ~70% of body length anterior to the cloaca. Fergusobia obliquae Davies n. sp. has a relatively broad, arcuate, parthenogenetic female having a small but strongly sclerotised stylet, and a short conoid tail with a bluntly rounded tip; an arcuate, infective female with an almost hemispherical tail tip; and C-shaped males with arcuate to angular (not heavily sclerotised) spicules and bursa arising 50-80% of body length anterior to tail. Sequencing of the 18S and 28S rDNA domains for F. janetae n. sp. and of mitochondrial DNA cytochrome oxidase subunit I (mtCOI) for F. pauciflorae n. sp. confirm that they are distinct species.


Assuntos
Myrtaceae , Animais , Austrália , Feminino , Masculino , Nematoides , Filogenia , Tumores de Planta
5.
BMC Evol Biol ; 18(1): 30, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29540154

RESUMO

BACKGROUND: Much evolutionary theory predicts that diversity arises via both adaptive radiation (diversification driven by selection against niche-overlap within communities) and divergence of geographically isolated populations. We focus on tropical fruit flies (Blepharoneura, Tephritidae) that reveal unexpected patterns of niche-overlap within local communities. Throughout the Neotropics, multiple sympatric non-interbreeding populations often share the same highly specialized patterns of host use (e.g., flies are specialists on flowers of a single gender of a single species of host plants). Lineage through time (LTT) plots can help distinguish patterns of diversification consistent with ecologically limited adaptive radiation from those predicted by ecologically neutral theories. Here, we use a time-calibrated phylogeny of Blepharoneura to test the hypothesis that patterns of Blepharoneura diversification are consistent with an "ecologically neutral" model of diversification that predicts that diversification is primarily a function of time and space. RESULTS: The Blepharoneura phylogeny showed more cladogenic divergence associated with geography than with shifts in host-use. Shifts in host-use were associated with ~ 20% of recent splits (< 3 Ma), but > 60% of older splits (> 3 Ma). In the overall tree, gamma statistic and maximum likelihood model fitting showed no evidence of diversification rate changes though there was a weak signature of slowing diversification rate in one of the component clades. CONCLUSIONS: Overall patterns of Blepharoneura diversity are inconsistent with a traditional explanation of adaptive radiation involving decreases in diversification rates associated with niche-overlap. Sister lineages usually use the same host-species and host-parts, and multiple non-interbreeding sympatric populations regularly co-occur on the same hosts. We suggest that most lineage origins (phylogenetic splits) occur in allopatry, usually without shifts in host-use, and that subsequent dispersal results in assembly of communities composed of multiple sympatric non-interbreeding populations of flies that share the same hosts.


Assuntos
Tephritidae/classificação , Tephritidae/genética , Animais , Biodiversidade , Evolução Biológica , Ecologia , Flores , Especiação Genética , Geografia , Herbivoria , Funções Verossimilhança , Filogenia , Plantas , Simpatria
6.
Mol Phylogenet Evol ; 113: 84-112, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28539260

RESUMO

Current hypotheses of relationship among the species of the fruit fly genera Anastrepha and Toxotrypana are tested using sequence data from six DNA regions: the mitochondrial regions 16S, CAD, and COI, and the nuclear regions EF1a, PER, and PGD. DNA sequences were obtained from 146 species of Anastrepha, representing 19 of the 21 species groups as well as five of the six clades of the robusta group, and four species of Toxotrypana in addition to species of Hexachaeta, Pseudophorellia, Alujamyia, and 13 other tephritid genera used as outgroups. The results indicate that Hexachaeta is more closely related to the Molynocoelia group than to Toxotrypana and Anastrepha, and it is removed from the tribe Toxotrypanini. The group Anastrepha+Toxotrypana and the genus Toxotrypana are strongly supported as monophyletic, consistent with previous studies, but Toxotrypana arises within Anastrepha, confirming that Anastrepha as currently defined is paraphyletic. The placement of Toxotrypana within Anastrepha is clearly defined for the first time with high support, as the sister group to the cryptostrepha clade of the robusta group of Anastrepha. Within Anastrepha, the daciformis, dentata, leptozona, raveni, and striata species groups are highly supported clades. The serpentina group is recognized with lower support, and the fraterculus and pseudoparallela groups are supported with minor alterations. The robusta group is resolved as polyphyletic, but four of the six species clades within it are recovered monophyletic (one clade is not represented and another is represented by one species). The punctata and panamensis groups are resolved together in a clade. At least some species of the mucronota group are related, however this group requires further study. The benjamini, grandis, and spatulata groups appear to be polyphyletic. Relationships among the species groups are generally poorly resolved, with the following exceptions: (1) the lineage including Toxotrypana, the cryptostrepha clade, and the tripunctata group; (2) the sister group relationship of the daciformis+dentata groups; (3) a clade comprising the punctata and panamensis groups; and (4) the large clade comprising the pseudoparallela+spatulata+ramosa+grandis+serpentina+striata+fraterculus groups.


Assuntos
Filogenia , Tephritidae/classificação , Tephritidae/genética , Animais , Funções Verossimilhança , Modelos Biológicos
7.
J Insect Sci ; 17(1)2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28423426

RESUMO

Liriomyza huidobrensis (Blanchard) is native to South America but has expanded its range and invaded many regions of the world, primarily on flowers and to a lesser extent on horticultural product shipments. As a result of initial invasion into an area, damage caused is usually significant but not necessarily sustained. Currently, it is an economic pest in selected native and invaded regions of the world. Adults cause damage by puncturing abaxial and adaxial leaf surfaces for feeding and egg laying sites. Larvae mine the leaf parenchyma tissues which can lead to leaves drying and wilting. We have recorded 365 host plant species from 49 families and more than 106 parasitoid species. In a subset of the Argentinian data, we found that parasitoid community composition attacking L. huidobrensis differs significantly in cultivated and uncultivated plants. No such effect was found at the world level, probably due to differences in collection methods in the different references. We review the existing knowledge as a means of setting the context for new and unpublished data. The main objective is to provide an update of widely dispersed and until now unpublished data, evaluate dispersion of the leafminer and management strategies in different regions of the world, and highlight the need to consider the possible effects of climate change on further regional invasions or expansions.


Assuntos
Dípteros/fisiologia , Dípteros/parasitologia , Herbivoria , Controle de Insetos , Espécies Introduzidas , Agricultura , Animais , Argentina , Clima , Dípteros/crescimento & desenvolvimento , Larva/parasitologia , Larva/fisiologia
8.
Ecol Evol ; 6(23): 8632-8644, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28031813

RESUMO

Diatraea lineolata and Diatraea saccharalis (Lepidoptera: Crambidae) are moths with stemboring larvae that feed and develop on economically important grasses. This study investigated whether these moths have diverged from a native host plant, corn, onto introduced crop plants including sorghum, sugarcane, and rice. Diatraea larvae were collected from these four host plants throughout the year in El Salvador and were reared on artificial diet until moths or parasitoids emerged. Adult moths were subsequently identified to species. Amplified fragment length polymorphisms (AFLPs) and mitochondrial DNA cytochrome oxidase I (COI) were used to examine whether or not there was genetic divergence of D. lineolata or D. saccharalis populations on the four host plants. Percent parasitism was also determined for each moth on its host plants. D. lineolata was collected from corn in the rainy season and sorghum in the dry season. D. saccharalis was most abundant on sugarcane in the rainy season and sorghum in the dry season. The AFLP analysis found two genetically divergent populations of both D. lineolata and D. saccharalis. Both moths had high levels of parasitism on their dominant host plant in the rainy season, yet had low levels of parasitism on sorghum in the dry season. The presence of two genotypes of both Diatraea spp. on sorghum suggest that host-associated differentiation is occurring on this novel introduced crop plant.

9.
Ecol Evol ; 6(18): 6565-6577, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27777730

RESUMO

Evolutionary radiations have been well documented in plants and insects, and natural selection may often underly these radiations. If radiations are adaptive, the diversity of species could be due to ecological speciation in these lineages. Agromyzid flies exhibit patterns of repeated host-associated radiations. We investigated whether host-associated population divergence and evidence of divergent selection exist in the leaf miner Phytomyza glabricola on its sympatric host plants, the holly species, Ilex coriacea and I. glabra. Using AFLPs and nuclear sequence data, we found substantial genetic divergence between host-associated populations of these flies throughout their geographic range. Genome scans using the AFLP data identified 13 loci under divergent selection, consistent with processes of ecological speciation. EF-1α data suggest that I. glabra is the original host of P. glabricola and that I. coriacea is the novel host, but the AFLP data are ambiguous with regard to directionality of the host shift.

10.
PLoS One ; 9(10): e110036, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25337705

RESUMO

The sugarcane borer moth, Diatraea saccharalis, is widespread throughout the Western Hemisphere, and is considered an introduced species in the southern United States. Although this moth has a wide distribution and is a pest of many crop plants including sugarcane, corn, sorghum and rice, it is considered one species. The objective was to investigate whether more than one introduction of D. saccharalis had occurred in the southern United States and whether any cryptic species were present. We field collected D. saccharalis in Texas, Louisiana and Florida in the southern United States. Two molecular markers, AFLPs and mitochondrial COI, were used to examine genetic variation among these regional populations and to compare the sequences with those available in GenBank and BOLD. We found geographic population structure in the southern United States which suggests two introductions and the presence of a previously unknown cryptic species. Management of D. saccharalis would likely benefit from further investigation of population genetics throughout the range of this species.


Assuntos
DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Proteínas de Insetos/genética , Mariposas/genética , Filogeografia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , Sequência de Bases , Feminino , Florida , Espécies Introduzidas , Louisiana , Masculino , Dados de Sequência Molecular , Mariposas/classificação , Filogenia , Saccharum/parasitologia , Texas
11.
Science ; 343(6176): 1240-4, 2014 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-24626926

RESUMO

Ecological specialization should minimize niche overlap, yet herbivorous neotropical flies (Blepharoneura) and their lethal parasitic wasps (parasitoids) exhibit both extreme specialization and apparent niche overlap in host plants. From just two plant species at one site in Peru, we collected 3636 flowers yielding 1478 fly pupae representing 14 Blepharoneura fly species, 18 parasitoid species (14 Bellopius species), and parasitoid-host associations, all discovered through analysis of molecular data. Multiple sympatric species specialize on the same sex flowers of the same fly host-plant species-which suggests extreme niche overlap; however, niche partitioning was exposed by interactions between wasps and flies. Most Bellopius species emerged as adults from only one fly species, yet evidence from pupae (preadult emergence samples) show that most Bellopius also attacked additional fly species but never emerged as adults from those flies.


Assuntos
Cucurbitaceae/parasitologia , Cadeia Alimentar , Herbivoria , Tephritidae/parasitologia , Vespas/fisiologia , Animais , Sequência de Bases , Biodiversidade , Flores/parasitologia , Dados de Sequência Molecular , Peru , Pupa/parasitologia , Tephritidae/embriologia
12.
J Econ Entomol ; 107(5): 1959-64, 2014 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-26309286

RESUMO

Liriomyza huidobrensis (Blanchard) is a highly destructive invasive leafminer pest currently causing extensive damage to vegetable and horticultural crops around the world. Liriomyza langei Frick is a leafminer pest native to California that cannot currently be morphologically distinguished from L. huidobrensis. We used a DNA-barcoding approach, a published PCR-RFLP method, and a new multiplex PCR method to analyze 664 flies matching the morphological description of huidobrensis-langei. We found no evidence for the presence of L. huidobrensis in our extensive samples from California. In addition to the new molecular method, this work is important because it provides definitive data that the California "pea leafminer" is currently, and has probably always been, L. langei. These data will also be important in the event that the highly invasive L. huidobrensis ever becomes established.


Assuntos
Dípteros/genética , Animais , California , Código de Barras de DNA Taxonômico , Dípteros/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Proteínas de Insetos/genética , Espécies Introduzidas , Masculino , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNA
13.
PLoS One ; 8(9): e73976, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24058509

RESUMO

Recently diverged taxa often show discordance in genetic divergence among genomic loci, where some loci show strong divergence and others show none at all. Genetic studies alone cannot distinguish among the possible mechanisms but experimental studies on other aspects of divergence may provide guidance in the inference of causes of observed discordances. In this study, we used no-choice mating trials to test for the presence of reproductive isolation between host races of the leaf-mining fly, Phytomyza glabricola on its two holly host species, Ilex coriacea and I. glabra. These trials inform our effort to determine the cause of significant differences in the degree of divergence of nuclear and mitochondrial loci of flies collected from the two host plants. We present evidence of reproductive isolation between host races in a controlled greenhouse setting: significantly more mate pairs consisting of flies from the same host plant species produced offspring than inter-host mate pairs, which produced no offspring. We also tested whether the presence of the natal or non-natal host plant affects reproductive success. Flies collected from I. coriacea were more likely to produce offspring when in the presence of the natal host, whereas the presence or absence of either the natal or non-natal host had no effect on flies collected from I. glabra. The results indicate discordant patterns of nuclear and mitochondrial divergence among host races of P. glabricola are likely due to incomplete lineage sorting, and the host races may be well on their way to becoming biological species.


Assuntos
Dípteros/genética , Especiação Genética , Genoma de Inseto , Isolamento Reprodutivo , Animais , Dípteros/classificação , Aptidão Genética , Loci Gênicos , Variação Genética , Especificidade de Hospedeiro , Ilex/parasitologia , North Carolina , Filogeografia , South Carolina
14.
Mol Ecol ; 21(23): 5892-904, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23094653

RESUMO

Our study investigated the importance of variability in the parasitoid community as a source of selection on host group size using a field population of the tupelo leafminer, Antispila nysaefoliella Clemens, which specializes on tupelo, Nyssa sylvatica Marsh. Larvae were collected from leaves with variable numbers of larvae and screened for parasitism using polymerase chain reaction of mitochondrial cytochrome oxidase I using markers designed specifically for amplifying parasitoid DNA while excluding host DNA. This method of selective PCR was effective for detecting the presence and identifying species of immature stages of three hymenopteran superfamilies: Chalcidoidea, Ichneumonoidea and Platygastroidea, which represented 83.4%, 16.0% and 0.6% of the total detectable parasitism, respectively. Our resulting sequences were then calibrated with sequences from identified adult parasitoids that had been either reared or field-captured. A cluster analysis revealed 10 distinct clades that showed differences in attack patterns with respect to host traits and season. Total parasitism followed an inverse density-dependent or density-independent pattern with respect to host density (number per leaf). However, when parasitoid taxa were considered separately, one clade, which could be a cryptic species of Pnigalio maculipes Crawford (Chalcidoidea: Eulophidae), was found to increase its per leaf attack rate with host density. Our results suggest that parasitoid community composition and differences among species in their attack strategies can play a large role in determining the adaptive advantage of host grouping.


Assuntos
Interações Hospedeiro-Parasita , Himenópteros/genética , Lepidópteros/genética , Lepidópteros/parasitologia , Animais , Análise por Conglomerados , Complexo IV da Cadeia de Transporte de Elétrons/genética , Larva , Dados de Sequência Molecular , Folhas de Planta , Reação em Cadeia da Polimerase/métodos , Densidade Demográfica
15.
Mol Phylogenet Evol ; 54(3): 746-62, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20040375

RESUMO

The acalyptrate fly superfamily Opomyzoidea, as currently recognized, is a poorly-known group of 14 families. The composition of this group and relationships among included families have been controversial. Furthermore, the delimitation of two opomyzoid families, Aulacigastridae and Periscelididae, has been unstable with respect to placement of the genera Stenomicra, Cyamops, and Planinasus. To test the monophyly of Opomyzoidea, previously proposed relationships between families, and the position of the three problematic genera, we sequenced over 3300bp of nucleotide sequence data from the 28S ribosomal DNA and CAD (rudimentary) genes from 29 taxa representing all opomyzoid families, as well as 13 outgroup taxa. Relationships recovered differed between analyses, and only branches supporting well-established monophyletic families were recovered with high support, with a few exceptions. Opomyzoidea and its included subgroup, Asteioinea, were found to be non-monophyletic. Stenomicra, Cyamops, and Planinasus group consistently with Aulacigastridae, contrary to recent classifications. Xenasteiidae and Australimyzidae, two small, monogeneric families placed in separate superfamilies, were strongly supported as sister groups.


Assuntos
Dípteros/classificação , Evolução Molecular , Filogenia , Animais , Dípteros/genética , Genes de Insetos , Funções Verossimilhança , Modelos Genéticos , RNA Ribossômico 28S/genética , Análise de Sequência de DNA
16.
Proc Natl Acad Sci U S A ; 106(43): 18103-8, 2009 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-19805134

RESUMO

A central but little-tested prediction of "escape and radiation" coevolution is that colonization of novel, chemically defended host plant clades accelerates insect herbivore diversification. That theory, in turn, exemplifies one side of a broader debate about the relative influence on clade dynamics of intrinsic (biotic) vs. extrinsic (physical-environmental) forces. Here, we use a fossil-calibrated molecular chronogram to compare the effects of a major biotic factor (repeated shift to a chemically divergent host plant clade) and a major abiotic factor (global climate change) on the macroevolutionary dynamics of a large Cenozoic radiation of phytophagous insects, the leaf-mining fly genus Phytomyza (Diptera: Agromyzidae). We find one of the first statistically supported examples of consistently elevated net diversification accompanying shift to new plant clades. In contrast, we detect no significant direct effect on diversification of major global climate events in the early and late Oligocene. The broader paleoclimatic context strongly suggests, however, that climate change has at times had a strong indirect influence through its effect on the biotic environment. Repeated rapid Miocene radiation of these flies on temperate herbaceous asterids closely corresponds to the dramatic, climate-driven expansion of seasonal, open habitats.


Assuntos
Clima , Dípteros/fisiologia , Animais , Comportamento Animal , Dípteros/genética , Fósseis , Dados de Sequência Molecular , Filogenia , Folhas de Planta , Dinâmica Populacional , Temperatura
17.
Science ; 320(5878): 928-31, 2008 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-18487192

RESUMO

The diversity of tropical herbivorous insects has been explained as a direct function of plant species diversity. Testing that explanation, we reared 2857 flies from flowers and seeds of 24 species of plants from 34 neotropical sites. Samples yielded 52 morphologically similar species of flies and documented highly conserved patterns of specificity to host taxa and host parts. Widespread species of plants can support 13 species of flies. Within single populations of plants, we typically found one or more fly species specific to female flowers and multiple specialists on male flowers. We suggest that neotropical herbivorous insect diversity is not simply a function of plant taxonomic and architectural diversity, but also reflects the geographic distribution of hosts and the age and area of the neotropics.


Assuntos
Biodiversidade , Cucurbitaceae , Dípteros , Animais , Cucurbitaceae/anatomia & histologia , Cucurbitaceae/classificação , Cucurbitaceae/fisiologia , Dípteros/anatomia & histologia , Dípteros/classificação , Dípteros/genética , Dípteros/fisiologia , Flores , Especiação Genética , Geografia , Funções Verossimilhança , México , Dados de Sequência Molecular , Filogenia , Sementes , Especificidade da Espécie , Clima Tropical
18.
Mol Ecol ; 16(13): 2627-37, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17594435

RESUMO

Host races play a central part in understanding the role of host plant mediated divergence and speciation of phytophagous insects. Of greatest interest are host-associated populations that have recently diverged; however, finding genetic evidence for very recent divergences is difficult because initially only a few loci are expected to evolve diagnostic differences. The holly leafminer Phytomyza glabricola feeds on two hollies, Ilex glabra and I. coriacea, that are broadly sympatric throughout most of their ranges. The leafminer is often present on both host plants and exhibits a dramatic life history difference on the two hosts, suggesting that host races may be present. We collected 1393 bp of mitochondrial cytochrome oxidase I (COI) sequence and amplified fragment length polymorphism (AFLP) data (45 polymorphic bands) from sympatric populations of flies reared from the two hosts. Phylogenetic and frequency analysis of mitochondrial COI sequence data uncovered considerable variation but no structuring by the host plant, and only limited differentiation among geographical locations. In contrast, analysis of AFLP frequency data found a significant effect with host plant, and a much smaller effect with geographical location. Likewise, neighbour-joining analysis of AFLP data resulted in clustering by host plant. The AFLP data indicate that P. glabricola is most likely comprised of two host races. Because there were no fixed differences in mitochondrial or AFLP data, this host-associated divergence is likely to have occurred very recently. P. glabricola therefore provides a new sympatric system for exploring the role of geography and ecological specialization in the speciation of phytophagous insects.


Assuntos
Variação Genética , Ilex/genética , Folhas de Planta/parasitologia , Plantas/parasitologia , Animais , DNA Mitocondrial/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Ilex/classificação , Ilex/enzimologia , Mitocôndrias/enzimologia , North Carolina , Filogenia , South Carolina
19.
Mol Phylogenet Evol ; 45(1): 123-41, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17434761

RESUMO

Fergusobia nematodes (Tylenchida: Fergusobiinae) and Fergusonina flies (Diptera: Fergusoninidae) are putative mutualists that develop together in galls formed in meristematic tissues of many species of the plant family Myrtaceae in Australasia. Fergusobia nematodes were sampled from a variety of myrtaceous hosts and gall types from Australia and one location in New Zealand between 1999 and 2006. Evolutionary relationships of these isolates were inferred from phylogenetic analyses of the DNA sequences of the nuclear ribosomal DNA near-full length small subunit (up to 1689bp for 21 isolates), partial large subunit D2/D3 domain (up to 889bp for 87 isolates), partial mitochondrial cytochrome oxidase subunit I (618 bp for 82 isolates), and combined D2/D3 and mtCOI (up to 1497bp for 66 isolates). The SSU data supported a monophyletic Fergusobia genus within a paraphyletic Howardula. A clade of Drosophila-associated Howardula, including Howardula aoronymphium, was the closest sequenced sister group. Phylogenetic analysis of sequences from D2/D3 and mtCOI, separately and combined, revealed many monophyletic clades within Fergusobia. The relationships inferred by D2/D3 and mtCOI were congruent with some exceptions. Well-supported clades were generally consistent with host plant species and gall type. However, phylogenetic analysis suggested host switching or putative hybridization events in many groups, except the lineage of shoot bud gallers on the broad-leaved Melaleuca species complex.


Assuntos
Evolução Molecular , Filogenia , Plantas/parasitologia , Tylenchida/genética , Tylenchida/fisiologia , Animais , Austrália , DNA Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Interações Hospedeiro-Parasita/genética , Subunidades Proteicas/análise , Subunidades Proteicas/genética , Alinhamento de Sequência
20.
Mol Phylogenet Evol ; 42(3): 756-75, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17291785

RESUMO

The leaf-mining flies (Diptera: Agromyzidae) are a diverse group whose larvae feed internally in leaves, stems, flowers, seeds, and roots of a wide variety of plant hosts. The systematics of agromyzids has remained poorly known due to their small size and morphological homogeneity. We investigated the phylogenetic relationships among genera within the Agromyzidae using parsimony and Bayesian analyses of 2965 bp of DNA sequence data from the mitochondrial COI gene, the nuclear ribosomal 28S gene, and the single copy nuclear CAD gene. We included 86 species in 21 genera, including all but a few small genera, and spanning the diversity within the family. The results from parsimony and Bayesian analyses were largely similar, with major groupings of genera in common. Specifically, both analyses recovered a monophyletic Phytomyzinae and a monophyletic Agromyzinae. Within the subfamilies, genera found to be monophyletic given our sampling include Agromyza, Amauromyza, Calycomyza, Cerodontha, Liriomyza, Melanagromyza, Metopomyza, Nemorimyza, Phytobia, and Pseudonapomyza. Several genera were found to be polyphyletic or paraphyletic including Aulagromyza, Chromatomyia, Phytoliriomyza, Phytomyza, and Ophiomyia. We evaluate our findings and discuss host-use evolution in light of current agromyzid taxonomy and two recent hypotheses of relationships based on morphological data.


Assuntos
Dípteros/genética , Evolução Molecular , Genes de Insetos , Filogenia , Análise de Sequência de DNA , Animais , Dípteros/fisiologia , Comportamento Alimentar/fisiologia , Interações Hospedeiro-Parasita/genética , Folhas de Planta/parasitologia
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