RESUMEN
Species of Horismenus Walker associated with bruchid beetles are investigated and five new species are described. Some of the new species are very similar to already described species and have previously been misidentified. The new species include H. depressoides sp. nov. similar to H. depressus Gahan , H. stator sp. nov. similar to H. missouriensis (Ashmead), and H. dennoi H. multistriatus spp. nov., both similar to H. butcheri Hansson Aebi and one species, H. gabrielae sp. nov., that is morphologically distinct from the other species but also associated with this host group. All 14 Horismenus species associated with bruchid beetles are included in a key. New host and distributional records are included for H. depressus.
Asunto(s)
Escarabajos , Himenópteros , AnimalesRESUMEN
Horismenus parasitoids are an abundant and understudied group of eulophid wasps found mainly in the New World. Recent surveys based on morphological analyses in Costa Rica have quadrupled the number of named taxa, with more than 400 species described so far. This recent revision suggests that there is still a vast number of unknown species to be identified. As Horismenus wasps have been widely described as parasitoids of insect pests associated with crop plants, it is of high importance to properly establish the extant diversity of the genus, in order to provide biological control practitioners with an exhaustive catalog of putative control agents. In this study, we first collected Horismenus wasps from wild Phaseolus bean seeds in Central Mexico and Arizona to assess the genetic relatedness of three morphologically distinct species with overlapping host and geographical ranges. Sequence data from two nuclear and two mitochondrial gene regions uncovered three cryptic species within each of the three focal species (i.e., H. missouriensis, H. depressus and H. butcheri). The monophyly of each cryptic group is statistically supported (except in two of them represented by one single tip in which monophyly cannot be tested). The phylogenetic reconstruction is discussed with respect to differences between gene regions as well as likely reasons for the differences in variability between species.
Asunto(s)
ADN/genética , Avispas/genética , Distribución Animal , Animales , Arizona , Teorema de Bayes , Escarabajos/parasitología , ADN Mitocondrial/genética , Ecosistema , Evolución Molecular , Femenino , Variación Genética , Especificidad del Huésped , Mutación INDEL , Masculino , México , Control Biológico de Vectores , Phaseolus , Filogenia , Alineación de Secuencia , Homología de Secuencia de Ácido Nucleico , Especificidad de la Especie , Avispas/clasificaciónRESUMEN
Although substantial epidemiologic evidence links Streptococcus mutans to caries, the pathobiology of caries may involve more complex communities of bacterial species. Molecular methods for bacterial identification and enumeration now make it possible to more precisely study the microbiota associated with dental caries. The purpose of this study was to compare the bacteria found in early childhood caries (ECC) to those found in caries-free children by using molecular identification methods. Cloning and sequencing of bacterial 16S ribosomal DNAs from a healthy subject and a subject with ECC were used for identification of novel species or uncultivated phylotypes and species not previously associated with dental caries. Ten novel phylotypes were identified. A number of species or phylotypes that may play a role in health or disease were identified and warrant further investigation. In addition, quantitative measurements for 23 previously known bacterial species or species groups were obtained by a reverse capture checkerboard assay for 30 subjects with caries and 30 healthy controls. Significant differences were observed for nine species: S. sanguinis was associated with health and, in order of decreasing cell numbers, Actinomyces gerencseriae, Bifidobacterium, S. mutans, Veillonella, S. salivarius, S. constellatus, S. parasanguinis, and Lactobacillus fermentum were associated with caries. These data suggest that A. gerencseriae and other Actinomyces species may play an important role in caries initiation and that a novel Bifidobacterium may be a major pathogen in deep caries. Further investigation could lead to the identification of targets for biological interventions in the caries process and thereby contribute to improved prevention of and treatment for this significant public health problem.