16 resultados para Gall wasps


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Most museums, libraries, and archives throughout the world have to deal with paper damaged by iron gall ink. For more than a decade international research has been devoted to the topic in an attempt to provide practical treatments for objects and formulate guidelines for the preservation of iron gall ink collections. A working group of conservators in South and Central America and the Caribbean have developed a program to disseminate research findings, collect data about the condition of iron gall ink collections in their countries and identify imminent training needs. The goal of this project is to combine the latest research with existing and acceptable conservation practices and share information about risk management, proper housing, examination and treatment of iron gall ink inscribed artefacts-at risk. Communications among colleagues were established to learn more about the current resources available in collections from various countries.

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The objective of the present study was to evaluate the plasticity of the hunting behavior of the spider Nephilengys cruentata (Araneae: Nephilidae) facing different species of social wasps. Considering that wasps can consume various species of spiders and that their poison can be used as defense against many predators, the effect of the corporal size of the prey was evaluated in the behavior of N. cruentata. Predation experiments were conducted using three species of social wasps of different sizes and the data registered in this research were compiled through annotations and filming of the hunting behavior of each spider, in relation to the offered prey. The results revealed that the size of the wasp and the sequential offer of prey change the hunting behavior of the spider, and prey of large size have high influence on this behavior.

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Hymenopteran parasitoids have been shown to be of potential value in tick biocontrol. Tick parasitoids has been reported only once in Brazil, over 95 yr ago when Ixodiphagus hookeri (Howard) was reported parasitizing Rhipicephalus sanguineus (Latreille) nymphs in Rio de Janeiro. Herein, we report the occurrence of Ixodiphagus spp. in ticks from three different regions of Brazil. In the state of Maranhao, in northeastern Brazil, parasitoids were detected in R. sanguineus nymphs on three occasions, during August 2009 and September 2010 (dry season), and January 2011 (rainy season). All parasitoids found in northeastern Brazil were identified as I. hookeri. In the state of Mato Grosso do Sul (westDcentral Brazil), one Amblyomma sp. engorged nymph was shown to be parasitized by I. hookeri. In the state of Rondonia (northern Brazil), one Amblyomma sp. engorged nymph was parasitized by Ixodiphagus texanus (Howard). Because Ixodiphagus spp. are present in ecologically distinct and geographically distant areas of Brazil, they are of potential use for biocontrol in the country.

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Mutualisms such as the figfig wasp mutualism are generally exploited by parasites. We demonstrate that amongst nonpollinating fig wasps (NPFWs) parasitic on Ficus citrifolia, a species of Idarnes galls flowers and another species feeds on galls induced by other wasps killing their larvae. The galling wasp inserts its ovipositor through the fig wall into the fig cavity. The ovipositor then follows a sinuous path and is introduced through the stigma and style of the flower. The egg is deposited between the integument and nucellus, in the exact location where the pollinating mutualistic wasp would have laid its egg. Gall induction is a complex process. In contrast, the path followed by the ovipositor of the other species is straightforward: attacking a larva within a developed gall poses different constraints. Shifts in feeding regime have occurred repeatedly in NPFWs. Monitoring traits associated with such repeated evolutionary shifts may help understand underlying functional constraints. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106, 114122.

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It is thought that speciation in phytophagous insects is often due to colonization of novel host plants, because radiations of plant and insect lineages are typically asynchronous. Recent phylogenetic comparisons have supported this model of diversification for both insect herbivores and specialized pollinators. An exceptional case where contemporaneous plant-insect diversification might be expected is the obligate mutualism between fig trees (Ficus species, Moraceae) and their pollinating wasps (Agaonidae, Hymenoptera). The ubiquity and ecological significance of this mutualism in tropical and subtropical ecosystems has long intrigued biologists, but the systematic challenge posed by >750 interacting species pairs has hindered progress toward understanding its evolutionary history. In particular, taxon sampling and analytical tools have been insufficient for large-scale cophylogenetic analyses. Here, we sampled nearly 200 interacting pairs of fig and wasp species from across the globe. Two supermatrices were assembled: on an average, wasps had sequences from 77% of 6 genes (5.6 kb), figs had sequences from 60% of 5 genes (5.5 kb), and overall 850 new DNA sequences were generated for this study. We also developed a new analytical tool, Jane 2, for event-based phylogenetic reconciliation analysis of very large data sets. Separate Bayesian phylogenetic analyses for figs and fig wasps under relaxed molecular clock assumptions indicate Cretaceous diversification of crown groups and contemporaneous divergence for nearly half of all fig and pollinator lineages. Event-based cophylogenetic analyses further support the codiversification hypothesis. Biogeographic analyses indicate that the present-day distribution of fig and pollinator lineages is consistent with a Eurasian origin and subsequent dispersal, rather than with Gondwanan vicariance. Overall, our findings indicate that the fig-pollinator mutualism represents an extreme case among plant-insect interactions of coordinated dispersal and long-term codiversification.

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Body size influences wing shape and associated muscles in flying animals which is a conspicuous phenomenon in insects, given their wide range in body size. Despite the significance of this, to date, no detailed study has been conducted across a group of species with similar biology allowing a look at specific relationship between body size and flying structures. Neotropical social vespids are a model group to study this problem as they are strong predators that rely heavily on flight while exhibiting a wide range in body size. In this paper we describe the variation in both wing shape, as wing planform, and mesosoma muscle size along the body size gradient of the Neotropical social wasps and discuss the potential factors affecting these changes. Analyses of 56 species were conducted using geometric morphometrics for the wings and lineal morphometrics for the body; independent contrast method regressions were used to correct for the phylogenetic effect. Smaller vespid species exhibit rounded wings, veins that are more concentrated in the proximal region, larger stigmata and the mesosoma is proportionally larger than in larger species. Meanwhile, larger species have more elongated wings, more distally extended venation, smaller stigmata and a proportionally smaller mesosoma. The differences in wing shape and other traits could be related to differences in flight demands caused by smaller and larger body sizes. Species around the extremes of body size distribution may invest more in flight muscle mass than species of intermediate sizes.

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Recent studies on the obligate interaction between fig trees and their pollinating agaonid wasps have focused on population aspects and wasp-seed exploitation at the level of the inflorescence. Detailed studies on larval and gall development are required to more fully understand how resources are exploited and adaptations fine-tuned by each partner in nursery pollination mutualisms. We studied the larval development of the active pollinating fig wasp, Pegoscapus sp., and the galling process of individual flowers within the figs of its monoecious host, Ficus citrifolia, in Brazil. The pollinator development is strongly dependent on flower pollination. Figs entered by pollen-free wasps were in general more likely to abort. Retained, unpollinated figs had both higher larval mortality and a lower number of wasps. Pegoscapus sp. larvae are adapted to plant development, with two contrasting larval feeding strategies proceeding alongside gall development. The first two larval stages behave as ovary parasites. Later larval stages feed on hypertrophied endosperm. This indicates that a successful galling process relies on endosperm, and also reveals why pollination would be a prerequisite for the production of high-quality galls for this Pegoscapus species.

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Mischocyttarus cassununga, a primitively eusocial Brazilian wasp, commonly found in urban environments, is an interesting model for studies on the evolution of social behaviour in hymenopteran insects. In this study, we constructed a microsatellite-enriched genomic library and presented primers for 18 microsatellite loci. For the analysis, 20 unrelated females were screened and all loci obtained were polymorphic. PCR amplification revealed from 3 (Mcas5b) to 17 (Mcas53b) alleles per locus (). We detected the levels of observed (H (o)) and expected (H (e)) heterozygosities ranging from 0.150 to 0.950 and 0.261 to 0.920, respectively. The polymorphic information content ranged from 0.238 to 0.915, averaging 0.680. All loci were in Hardy-Weinberg equilibrium and linkage disequilibrium was not detected after sequential Bonferroni correction (P > 0.05). These molecular markers will allow further studies on sociogenetic structure, extensive population genetic analysis and diversity of M. cassununga and other Mischocyttarini species.

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The present study describes different preimaginal stages of Trypoxylon rogenhoferi examined by Scanning Electron Microscopy (SEM) and compares the results with observations on closely related species. Some notes on the nesting habits of this species, including their spider prey, nest parasites, and development time are provided. In short, T. rogenhoferi proved quite similar to the previous report on T. albitarse although SEM images are rarely presented in such descriptions. In fact the present study emphasized the importance of SEM images to describe fine morphological details that can be useful characters for taxonomic and phylogenetic studies. Images of some earlier development stages (first and second larval instar and egg) are presented for the first time, and compared with the few available data from other hymenopterans.

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The immatures of Polybia paulista Ihering were described using light and scanning electron microscopy and the results are compared with previous descriptions within the same or related wasps. This study is based on 2 whole nests collected in the municipality of Rio Claro, Sao Paulo, in Brazil. We have detected the existence of 5 larval instars. The main morphological alterations over development occur in the relative size of structures, yet certain structures appear with subsequent instars and become more evident later in development: increasing density in the number of body spines and papillae; the appearance of body setae in fifth-instar larvae; opening of spiracles upon second-instar larvae; 2 body shapes in fifth-instar larvae; the appearance of a lateral tooth on the mandibles of fourth instar; presence of spines on the maxillae of fifth-instar larvae; altered shape of galea and palps upon third-instar larvae from a cluster of sensilla to a conical elevation; and the appearance of spines on postmentum upon fourth-instar larvae. This way, the present study presents a detailed description of the immatures of P. paulista, and we hope the presented information can be useful to morphological, taxonomic, and phylogenetic studies.

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Evania appendigaster is a cosmopolitan wasp that deposits eggs in the oothecae of some species of cockroaches; its larvae then consume the cockroach eggs and embryos. It is a candidate for the biological control of cockroaches, but little is known about its basic biology. Here we describe the external morphology of all immature stages of E. appendigaster and compare them with the larvae of related species. The life cycle of E. appendigaster includes three larval instars, each with 13 body segments. Their mouthparts were generally reduced, except for the mandibles, which were always sclerotized and toothed, and were especially robust in second-instar larvae. Antennal and mouthpart sensilla were basiconic and difficult to observe. Larvae of E. appendigaster are similar in form to other described evaniid larvae, but quite different from the two available descriptions of larvae of gasteruptiid and aulacid wasps. Further descriptions of evaniid larvae will be useful in determining how widespread this morphology is within the family, and in understanding phylogenetic relationships within Hymenoptera.

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Herbivore-attacked plants produce specific volatile substances that represent important cues for host finding by natural enemies. The fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a voracious herbivore and usually feed on maize in all periods of the day. Given that plant needs light to synthesize de novo herbivore-induced volatiles, volatile blend may be changed depending on time of the day the plant is induced, what could interfere in natural enemy foraging. In this sense, the current study aimed to investigate differential attractiveness of maize elicited by fall armyworm regurgitant under light and dark conditions to its specialist larval parasitoid Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae). All bioassays were conducted in Y-tube olfactometer to assess parasitoid response to odors from undamaged maize, mechanical damage, and regurgitant-treated plants at 0-1, 5-6, and 24-25 h after induction. The results showed that na < ve wasps were attracted to volatiles emitted by nocturnal regurgitant-treated maize at 5-6 h, but not to odors from diurnal regurgitant-treated plants. The differential attractiveness is likely due to blend composition as nocturnal regurgitant-treated plants emit aromatic compounds and the homoterpene (3E)-4,8-dimethyl-1,3,7-nonatriene in larger amounts than diurnal-treated plants.

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The level structures of the N = 50 As-83, Ge-82, and Ga-81 isotones have been investigated by means of multi-nucleon transfer reactions. A first experiment was performed with the CLARA PRISMA setup to identify these nuclei. A second experiment was carried out with the GASP array in order to deduce the gamma-ray coincidence information. The results obtained on the high-spin states of such nuclei are used to test the stability of the N = 50 shell closure in the region of Ni-78 (Z = 28). The comparison of the experimental level schemes with the shell-model calculations yields an N = 50 energy gap value of 4.7(3) MeV at Z = 28. This value, in a good agreement with the prediction of the finite-range liquid-drop model as well as with the recent large-scale shell model calculations, does not support a weakening of the N = 50 shell gap down to Z = 28. (c) 2012 Elsevier B.V. All rights reserved.

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Division of labor among workers is common in insect societies and is thought to be important in their ecological success. In most species, division of labor is based on age (temporal castes), but workers in some ants and termites show morphological specialization for particular tasks (physical castes). Large-headed soldier ants and termites are well-known examples of this specialization. However, until now there has been no equivalent example of physical worker subcastes in social bees or wasps. Here we provide evidence for a physical soldier subcaste in a bee. In the neotropical stingless bee Tetragonisca angustula, nest defense is performed by two groups of guards, one hovering near the nest entrance and the other standing on the wax entrance tube. We show that both types of guards are 30% heavier than foragers and of different shape; foragers have relatively larger heads, whereas guards have larger legs. Low variation within each subcaste results in negligible size overlap between guards and foragers, further indicating that they are distinct physical castes. In addition, workers that remove garbage from the nest are of intermediate size, suggesting that they might represent another unrecognized caste. Guards or soldiers are reared in low but sufficient numbers (1-2% of emerging workers), considering that <1% usually perform this task. When challenged by the obligate robber bee Lestrimelitta limao, an important natural enemy, larger workers were able to fight for longer before being defeated by the much larger robber. This discovery opens up opportunities for the comparative study of physical castes in social insects, including the question of why soldiers appear to be so much rarer in bees than in ants or termites.

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Entering behavior of Gasteruption brachychaetum Schrottky (Hymenoptera, Gasteruptiidae) into a nest of Hylaeus Fabricius (Hymenoptera, Colletidae). Nests of Hylaeus aff. guaraniticus (Schrottky, 1906) were parasited by females of Gasteruption brachychaetum Schrottky, 1906 in trap nests in Sao Paulo(Brazil). This is the first host record of a Gasteruptiidae in the Neotropical Region. The behavior of a G. brachychaetum female entering a host's nest is described as follows: an inquiline female hovered near the host's nest, landed and detected that a female of H. aff. guaraniticus was inside the nest, waited for the host female to fly out, entered backwards into the nest, remained there for almost six minutes, and then went out the nest. The development time of immature stages of G. brachychaetum varied between 16 and 299 days.