42 research outputs found

    An Interdependent Metabolic Patchwork in the Nested Symbiosis of Mealybugs

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    SummaryHighly reduced genomes of 144–416 kilobases have been described from nutrient-provisioning bacterial symbionts of several insect lineages [1–5]. Some host insects have formed stable associations with pairs of bacterial symbionts that live in specialized cells and provide them with essential nutrients; genomic data from these systems have revealed remarkable levels of metabolic complementarity between the symbiont pairs [3, 4, 6, 7]. The mealybug Planococcus citri (Hemiptera: Pseudococcidae) contains dual bacterial symbionts existing with an unprecedented organization: an unnamed gammaproteobacteria, for which we propose the name Candidatus Moranella endobia, lives inside the betaproteobacteria Candidatus Tremblaya princeps [8]. Here we describe the complete genomes and metabolic contributions of these unusual nested symbionts. We show that whereas there is little overlap in retained genes involved in nutrient production between symbionts, several essential amino acid pathways in the mealybug assemblage require a patchwork of interspersed gene products from Tremblaya, Moranella, and possibly P. citri. Furthermore, although Tremblaya has the smallest cellular genome yet described, it contains a genomic inversion present in both orientations in individual insects, starkly contrasting with the extreme structural stability typical of highly reduced bacterial genomes [4, 9, 10]

    \u3ci\u3eNurudea zhengii\u3c/i\u3e Ren, A New Species of the \u3ci\u3eRhus\u3c/i\u3e Gall Aphids (Aphididae: Eriosomatinae: Fordini) from Eastern China

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    A new Rhus gall aphid species Nurudea zhengii Ren, sp. nov. collected from the Mountain Qixing in Shangrao County, Jiangxi Province, China is described and illustrated from alate viviparous female. The new species differs from the other Nurudea species in the length and proportion of antennal segments, the structure of antennal secondary sensilla, and the flower-like shape of the galls that are formed on its primary host. Its primary host plant is Rhus hypoleuca, whereas other Nurudea species are on R. chinensis

    The Geological Record and Phylogeny of Spider Wasps (Hymenoptera: Pompilidae): A Revision of Fossil Species and Their Phylogenetic Placement

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    Accurate fossil identification has become increasingly relevant with the widespread use of phylogenetic divergence time estimation methods, which rely on fossil data to determine clade hard-minimum ages. Here we revise, diagnose and illustrate known spider wasp (Hymenoptera: Pompilidae) fossil species and place them within the latest Pompilidae phylogenetic hypothesis. Ceropalites infelix Cockerell, from the Florissant Fossil Beds (Priabonian), is no longer recognized as Pompilidae, but as Aulacidae. Agenioideus saxigenus (Cockerell) comb. nov., Deuteragenia wettweri (Statz) comb. nov., Caputelus scudderi (Cockerell, 1906) comb. nov., Pepsinites avitula (Cockerell, 1941) comb. nov., Pepsinites contentus (Theobald, 1937) comb. nov., Pepsinites florissantensis (Cockerell, 1906) comb. nov., Pepsinites laminarum (Rohwer, 1909) comb. nov., Pepsinites scelerosus (Meunier, 1919) comb. nov., Pepsinites cockerellae(Rohwer, 1909) comb. nov., Pompilinites coquandi (Theobald, 1937) comb. nov., Pompilinites depressus (Statz, 1936) comb. nov., Pompilites incertus (Theobald, 1937) comb. nov.,Pompilites induratus (Heer, 1849) comb. nov., Pompilites fasciatus (Theobald, 1937) comb. nov., and Pompilites senex comb. nov. are new combinations. Twenty-three fossil species of spider wasps are now recognized in 13 genera. Four new genera are proposed: CaputelusWaichert & Pitts gen. nov., Pompilites Rodriguez gen. nov., Pompilinites Rodriguez & Waichert gen. nov., and Pepsinites Rodriguez & Waichert gen. nov., of which the three latter are collective-group names for fossils with taxonomic uncertainty. One species of fossil spider wasp is described: Deuteragenia catalunyia Rodriguez, Waichert & Pitts sp. nov., from the Bellver deposits in Catalonia, Spain. Five of the 23 known species can be used to determine hard-minimum age for calibrations of genera stem-groups (Agenioideus, Anoplius, Cryptocheilus, Deuteragenia, Priocnemis). The fossil belonging to the stem-group of the tribe Ageniellini (Chubutholites) is not recommended for calibration because of the high uncertainty in its age and taxonomy. The remaining taxa can be assigned to the lineage comprising Pompilinae + Pepsinae (12 species) or crown-group Pompilidae (four species)

    First American records of Aphis Intybi (Hemiptera: Aphididae) with notes on two other related adventive species in Argentina

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    P.1154-1162Aphis intybi Koch is recorded for the first time in North and South America. Measurements for the identification of this species in comparison with Aphis craccivora Koch are given. Aphis cytisorum Hartig is recorded for the third time in Argentina. Data on morphological variation, geographical distribution, and host plants of these species in Argentina are provided. Their morphological identification is supported by comparison of DNA sequences of the mitochondrial cytochrome oxidase subunit 1 (DNA barcode) and subunit 2.S

    Partnering With a Pest: Genomes of Hemlock Woolly Adelgid Symbionts Reveal Atypical Nutritional Provisioning Patterns in Dual-Obligate Bacteria

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    Nutritional bacterial symbionts enhance the diets of sap-feeding insects with amino acids and vitamins missing from their diets. In many lineages, an ancestral senior symbiont is joined by a younger junior symbiont. To date, an emergent pattern is that senior symbionts supply a majority of amino acids, and junior symbionts supply a minority. Similar to other hemipterans, adelgids harbor obligate symbionts, but have higher diversity of bacterial associates, suggesting a history of symbiont turnover. The metabolic roles of dual symbionts in adelgids and their contributions to the consortium are largely unexplored. Here, we investigate the symbionts of Adelges tsugae, the hemlock woolly adelgid (HWA), an invasive species introduced from Japan to the eastern United States, where it kills hemlock trees. The response of hemlocks to HWA feeding has aspects of a defensive reaction against pathogens, and some have speculated that symbionts may be involved. We sequenced the genomes of “Ca. Annandia adelgestsuga” and “Ca. Pseudomonas adelgestsugas” symbionts to detail their metabolic capabilities, infer ages of relationship, and search for effectors of plant defenses. We also tested the relationship of “Ca. Annandia” to symbionts of other insects. We find that both symbionts provide nutrients, but in more balanced proportions than dual symbionts of other hemipterans. The lesser contributions of the senior “Ca. Annandia” support our hypothesis for symbiont replacements in adelgids. Phylogenomic results were ambiguous regarding the position of “Ca. Annandia”. We found no obvious effectors of plant defenses related to insect virulence, but hypothetical proteins in symbionts are unknown players

    Molecular phylogeny and systematics of spider wasps (Hymenoptera: Pompilidae): Redefining subfamily boundaries and the origin of the family

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    Spider wasps (Hymenoptera: Pompilidae) constitute a monophyletic family supported by numerous morphological and behavioural traits. The subfamilial and tribal classifications, however, have a history of conflicting and confusing designations and nomenclature. Here, we reconstruct a molecular phylogeny of Pompilidae from Bayesian and maximum-likelihood analyses of four nuclear molecular markers (elongation factor-1 ë± F2 copy, long-wavelength rhodopsin, RNA polymerase II, and 28S ribosomal RNA). A Bayesian divergence-time estimation analysis was performed using four calibration points and an ancestral-area reconstruction was performed with a Bayesian binary Markov chain Monte Carlo method. New relationships are recovered, and new subfamilial delimitations are proposed and discussed based on the phylogeny. The origin of Pompilidae was c.43.3 Mya, probably in the Nearctic region. Most of the extant subfamilies originated from the late Eocene to the Oligocene, and their current distributions are the product of various dispersal events that occurred over the course of ‰ö_40 Mya. This is the first phylogenetic reconstruction of Pompilidae from molecular characters, with broad geographical and taxonomic sampling. The following subfamilies and relationships are recognized: Ctenocerinae+((Ceropalinae+Notocyphinae)+(Pompilinae+Pepsinae)). We revalidate Notocyphinae, which contains only Notocyphus, and define a new tribe in Pompilinae: Sericopompilini. Priochilini is reinstated. Sericopompilini contains Sericopompilus as the sole representative; Priochilini contains Priochilus and Balboana. Epipompilus and Chirodamus are now classified as Pepsinae. å© 2015 The Linnean Society of London

    Data from: The evolution of life cycle complexity in aphids: ecological optimization, or historical constraint?

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    For decades, biologists have debated why many parasites have obligate multi-host life cycles. Here, we use comparative phylogenetic analyses of aphids to evaluate the roles of ecological optimization and historical constraint in the evolution of life cycle complexity. If life cycle complexity is adaptive, it should be evolutionarily labile, i.e., change in response to selection. We provide evidence that this is true in some aphids (aphidines), but not others (non-aphidines) – groups that differ in the intensity of their relationships with primary hosts. Next, we test specific mechanisms by which life cycle complexity could be adaptive or a constraint. We find that among aphidines there is a strong association between complex life cycles and polyphagy but only a weak correlation between life cycle complexity and reproductive mode. In contrast, among non-aphidines the relationship between life cycle complexity and host breadth is weak but the association between complex life cycles and sexual reproduction is strong. Thus, although the adaptiveness of life cycle complexity appears to be lineage specific, across aphids, life cycle evolution appears to be tightly linked with the evolution of other important natural history traits

    Description of a new species of Hamamelistes forming galls on Fothergilla spp (Hamamelidaceae) and the generic limits of Hormaphidini (Sternorrhyncha Aphididae: Hormaphidinae)

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    Dederich, Ashley E., Halbert, Susan E., Von Dohlen, Carol D. (2022): Description of a new species of Hamamelistes forming galls on Fothergilla spp (Hamamelidaceae) and the generic limits of Hormaphidini (Sternorrhyncha Aphididae: Hormaphidinae). Zootaxa 5183 (1): 203-219, DOI: https://doi.org/10.11646/zootaxa.5183.1.1

    First american records of Aphis intybi (Hemiptera: Aphididae) with notes on two other related adventive species in Argentina

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    Aphis intybi Koch is recorded for the first time in North and South America. Measurements for the identification of this species in comparison with Aphis craccivora Koch are given. Aphis cytisorum Hartig is recorded for the third time in Argentina. Data on morphological variation, geographical distribution, and host plants of these species in Argentina are provided. Their morphological identification is supported by comparison of DNA sequences of the mitochondrial cytochrome oxidase subunit 1 (DNA barcode) and subunit 2.Aphis intybi Koch se cita por primera vez tanto en América del Sur como del Norte. Se aportan características métricas para la identificación de la especie en comparación con Aphis craccivora Koch. Aphis cytisorum Hartig se cita por tercera vez en la Argentina. Se aportan datos sobre la variación morfológica, así como sobre la distribución geográfica y las plantas hospedadoras en Argentina de esas especies. Las identificaciones morfológicas han sido corroboradas mediante comparaciones de las secuencias de la citocromo oxidasa I (DNA barcode) y de la citocromo oxidasa II del DNA mitocondrial.EEA MendozaFil: Mier Durante, Milagros Pilar. Universidad de León. Departamento de Biodiversidad y Gestión Ambiental (área de Zoología); EspañaFil: Foottit, Robert. Agriculture and Agri-Food Canada. Canadian National Collection of Insects. Invertebrate Biodiversity; CanadáFil: Dohlen, Carol D. Von. Utah State University. Department of Biology; Estados UnidosFil: Ortego, Jaime. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentin
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