957 resultados para Noctuidae Larvae


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BACKGROUND: Genetically modified MON 87701 X MON 89788 soybean (Glycine max), which expresses the Cry1Ac and EPSP-synthase proteins, has been registered for commercial use in Brazil. To develop an Insect Resistance Management (IRM) program for this event, laboratory and field studies were conducted to assess the high-dose concept and level of control it provides against Anticarsia gemmatalis and Pseudoplusia includens. RESULTS: The purified Cry1Ac protein was more active against A. gemmatalis [LC50 (FL 95%) = 0.23 (0.150.34) mu g Cry1Ac mL-1 diet] than P. includens [LC50 (FL 95%) = 3.72 (2.654.86) mu g Cry1Ac mL-1 diet]. In bioassays with freeze-dried MON 87701X MON 89788 soybean tissue diluted 25 times in an artificial diet, there was 100% mortality of A. gemmatalis and up to 95.79% mortality for P. includens. In leaf-disc bioassays and under conditions of high artificial infestation in the greenhouse and natural infestation in the field, MON 87701X MON 89788 soybean showed a high level of efficacy against both target pests. CONCLUSIONS: The MON 87701X MON 89788 soybean provides a high level of control against A. gemmatalis and P. includes, but a high-dose event only to A. gemmatalis. Copyright (c) 2012 Society of Chemical Industry

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In response to herbivore attack, plants release herbivore-induced plant volatiles (HIPVs) that represent important chemical cues for herbivore natural enemies. Additionally, HIPVs have been shown to mediate other ecological interactions with herbivores. Differently from natural enemies that are generally attracted to HIPVs, herbivores can be either attracted or repelled depending on several biological and ecological parameters. Our study aimed to assess the olfactory response of fall armyworm-mated female moths toward odors released by mechanically and herbivore-induced corn at different time intervals. Results showed that female moths strongly respond to corn volatiles, although fresh damaged corn odors (0-1 h) are not recognized by moths. Moreover, females preferred volatiles released by undamaged plant over herbivore-induced plants at 5-6 h. This preference for undamaged plants may reflect an adaptive strategy of moths to avoid competitors and natural enemies for their offspring. We discussed our results based on knowledge about corn volatile release pattern and raise possible explanations for fall armyworm moth behavior.

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Strongyloidiasis is an intestinal parasitosis with an obligatory pulmonary cycle. A Th2-type immune response is induced and amplifies the cellular response through the secretion of inflammatory mediators. Although this response has been described as being similar to asthma, airway remodeling during pulmonary migration of larvae has not yet been established. The aim of this study was to identify the occurrence of airway remodeling during Strongyloides venezuelensis (S. v.) infection and to determine the ability of dexamethasone treatment to interfere with the mechanisms involved in this process. Rats were inoculated with 9,000 S. v. larvae, treated with dexamethasone (2 mg/kg) and killed at 1, 3, 5, 7, 14 and 21 days. Morphological and morphometric analyzes with routine stains and immunohistochemistry were conducted, and some inflammatory mediators were evaluated using ELISA. Goblet cell hyperplasia and increased bronchiolar thickness, characterized by edema, neovascularization, inflammatory infiltrate, collagen deposition and enlargement of the smooth muscle cell layer were observed. VEGF, IL1-beta and IL-4 levels were elevated throughout the course of the infection. The morphological findings and the immunomodulatory response to the infection were drastically reduced in dexamethasone-treated rats. The pulmonary migration of S. venezuelensis larvae produced a transitory, but significant amount of airway remodeling with a slight residual bronchiolar fibrosis. The exact mechanisms involved in this process require further study. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

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In this study, we investigated the physiological alterations during ontogeny for cachara (Pseudoplatystoma reticulatum) and their hybrid larvae (Pseudoplatystoma corruscans x P. reticulatum) using lipids and fatty acids as physiological tools to elucidate the basis for differences in these groups' productivity in an industrial setting. Eggs and larvae samples were collected during January and February of 2008 in the city of Bandeirantes, MS, and were divided into three primary phases: phase I (0-16 h after fertilization); phase II (24 h after fertilization to 6 days after fertilization); and phase III (7-25 days after fertilization). The larvae of both groups showed a high degree of similarity, suggesting that the hybrid larvae showed a high level of heritability from the cachara broodstock. Analysis of the total lipid content provided evidence that there is no alteration in lipid concentration during ontogeny for both groups (i.e., the cachara and hybrids). However, the fatty acid profile showed that during the endogenous feeding period (phase II), when the larvae must use the energy reserves from the mother, the cachara larvae used mainly monounsaturated fatty acids for development. This is typical for most fish species, though notably, the hybrids preferentially used saturated fatty acids. Furthermore, certain specific changes demonstrate unique patterns of energy utilization and structural substrates, which may aid in elucidating the empirical differences reported by fish farmers (i.e., that the hybrids perform better than cacharas in captivity).

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The biological characteristics of Telenomus remus Nixon, 1937 (Hymenoptera: Platygastridae) on eggs of Spodoptera albula (Walker, 1857); S. cosmioides Walker 1858, S. eridania (Cramer, 1782); and S. frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) were evaluated under different temperatures (19, 22, 25, 28, 31, and 34 degrees C +/- 1 degrees C). The duration of the T remus egg-to-adult period on eggs of all four Spodoptera species and the longevity of adults of T. remus were both inversely proportional to the increase in temperature. Parasitoid emergence was higher than 80% at temperatures from 19 to 28 degrees C when the parasitoid was reared on eggs of S. eridania and S. frugiperda. Differently, when the parasitoid was reared on eggs of S. albula and S. cosmioides, T. remus emergence at rates of 80% or higher just occurred from 22 to 25 degrees C and at 22 degrees C, respectively. At 34 degrees C, this parameter was lower than 30% for T reams reared in all hosts. The sex ratio was 64-86% females, except for T. remus in S. cosmioides eggs at 34 C, in which temperature it was 39%. The estimated thermal requirements of T. remus, for the thermal constant (K) and the base temperature (T(base)), were: 125.39 DD and 15.139 degrees C; 125.56 DD and 14.912 degrees C; 142.98 DD and 14.197 degrees C; and 149.16 DD and 13.846 degrees C, for S. cosmioides, S. frugiperda, S. albula, and S. eridania, respectively. In general, T. remus showed good parasitism potential on all the hosts, although eggs of S. frugiperda, S. eridania, and S. albula proved to be the most suitable for mass rearing of T reams in the laboratory. Eggs of S. cosmioides are less suitable because of the lower parasitoid emergence observed at most of the temperatures with exception of 22 degrees C.

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The final instar larva of Mnesarete pudica is described and illustrated based on reared specimens collected in Brazil. This species can be distinguished from others by presenting: a) five palpal and three premental setae; b) no posterodorsal hooks on abdominal segments; c) lateral spines only in S9-10. M. pudica is compared to other South American calopterygids and biological notes are presented.

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In addition to the strong influence of the broodstock diet on the development and survival of offspring, domestication may also interfere with the larval life success. We obtained eggs from wild and domesticated Salminus hilarii females and domesticated males. Wild females were caught in the Tiete River and tributaries, and the domesticated females were born three years before the beginning of the experiment in the Ponte Nova Fish Farm. Animals from both groups were fed with the same feed to exclude feed variables. The eggs and larvae were sampled at 0, 8, 16, and 28 h after spawning (HAS), with the last sampling (28 HAS) coinciding with hatching time. After hatching, samplings proceeded at 32, 48, 66, and 96 HAS, with the last sampling (96 HAS) corresponding to the end of yolk sac consumption. Finally, the last experimental period was during the larvae exogenous feeding phase, at 102, 118, 166, and 214 HAS. Our data revealed that domestication of S. hilarii females influenced fatty acid (FA) metabolism during embryo and larva development. However, the structure of membrane phospholipid FA remained mostly stable, with changes principally in the neutral fraction. When the external conditions, mainly water and feed quality, remained constant, domestication of S. hilarii females did not significantly affect the structural FA composition but influenced the selectivity of consumption and/or storage of specific FA.

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This study was focused on the predation upon microcrustaceans by an invertebrate predator (chaoborid larvae), and vertebrate predators (fish), in two small reservoirs in southeastern Brazil, with and without macrophytes, in two climatic periods (dry and rainy seasons). Chaoborus larvae were sampled in the limnetic zone, as they are scarce in the littoral, and fish in both limnetic and littoral zones. Their diets were evaluated by the analysis of the crop (chaoborid) or stomach contents (fish). Chaoborid larvae consumed the dinoflagellate Peridinium sp. or other algae, rotifers, and planktonic microcrustaceans. The fish species that included microcrustaceans in their diets were juveniles caught in the littoral. Aquatic insects, plant fragments, and detritus were their major dietary items, microcrustaceans representing a minor item. Planktonic copepods contributed more to the diet of chaoborid larvae than planktonic cladocerans. Fish preyed on planktonic microcrustaceans, as well as on benthic and macrophyte-associated species. Microcrustaceans were not heavily preyed on by chaoborid larvae and fish in both reservoirs.

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Toxocariasis, caused most commonly by Toxocara canis, is an important cosmopolitan zoonosis. Paratenic hosts have been employed to provide knowledge regard to the transmission of toxocariasis. Transmammary transmission in murine experimentally infected was observed based on the recovery of larvae from the tissue. The aim of this study was to evaluate the possibility of transmammary transmission of Toxocara canis in rabbits by detecting larvae directly in milk. Seventeen sexually mature virgin white New Zealand female rabbits were divided into two groups. Twelve animals were orally inoculated with 1,000 T. canis embryonated eggs (infected group), and five animals remained uninfected (control group). One month following the infection, the females were mated. Manual collection of 500 ?L of milk from each rabbit was performed on days +7, +14 and +21 of lactation for three consecutive lactations. The recovery of larvae was determined via a centrifuge-sedimentation technique using ether and formalin solutions. ELISA test was run to confirm the production of anti-T. canis antibodies (IgG) by infected rabbits. The presence of larvae was observed in milk samples from 5 (41.7%) of the 12 infected rabbits. The total number of recovered larvae was 20, ranging from 1 to 4 larvae per lactation/rabbit. Larvae were recovered exclusively on days 7 and 14 of lactation. Recovery was verified in different lactations. No significant difference was observed with respect to the number of larvae either in the same lactation period or in different lactation periods. Anti-T. canis antibodies were detected in all infected rabbits. In conclusion, the presence of larvae in rabbit milk samples suggests the possibility of galactogenic transmission of T. canis in paratenic hosts. Moreover, the technique employed in this study allows for the recovery of larvae directly from milk.

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In October 1991, the horizontal distribution of invertebrate larvae was studied in the waters surrounding the island of Gran Canaria (Canary Islands). The cruise was typified by the presence of three recurrent mesoscale hydrographic structures: a cyclonic eddy southwest of the island, a warm lee region downstream of the island and the offshore boundary of an upwelling filament from the African coast reaching the southeast of the island. Decapod larvae were the most abundant group. In general, a rather high spatial variability was found. The horizontal distribution of the invertebrate larvae groups showed that the highest values of abundance occurred in an elongated zone around the island oriented in the overall direction of flow, leeward and windward of the island, while the lowest values occurred off the eastern and western flanks of the islands. On the other hand, Stomatopoda and Mollusca larvae showed a distribution associated with the boundary of the upwelling filament and decapod larvae of pelagic species were distributed around the eddy structure. Our results suggest specific retention mechanisms for the larvae of neritic invertebrate populations that are related to the particular physical oceanography around Gran Canaria. Se estudió la distribución horizontal de las larvas de invertebrados alrededor de la isla de Gran Canaria (Islas Canarias) en octubre de 1991. La campaña se caracterizó por la presencia de tres fenómenos oceanográficos de mesoescala recurrentes: un remolino ciclónico al suroeste de la isla, la estela cálida a sotavento de la misma y el borde de un filamento proveniente del afloramiento africano situado al sureste de Gran Canaria. Las larvas de crustáceos decápodos fueron las más abundantes. En general, las larvas de los diferentes taxa estudiados mostraron una gran variabilidad en cuanto a su distribución espacial. La distribución horizontal de las larvas de los diferentes grupos de invertebrados mostró que las densidades más altas se registraban alrededor de la isla en la banda cercana y orientada hacia el suroeste, en la dirección del flujo, mientras que los valores más bajos se encontraron en el norte y en los flancos este y oeste de la isla. Por otro lado, las larvas de estomatópodos y moluscos presentaron una distribución asociada al frente del filamento, mientras que las larvas de decápodos pelágicos se distribuyeron en torno al remolino ciclónico. Los resultados obtenidos sugieren la existencia de mecanismos de retención específicos para el mantenimiento de las poblaciones insulares, relacionados con los procesos físicos de mesoescala predominantes

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[EN]Red porgy is a candidate species for marine aquaculture diversification.The objective of the present study was to describe the osteological development and the occurrence of skeletal deformities in Pagrus pagrus larvae in relation to the intensification of the rearing system. Fish samples were periodically collected along the development from hatching to juveniles (95days after hatching). Osteological development and the presence of skeleton abnormalities were evaluated. X-ray studies revealed a high number of fish (Semi-intensive:38.8%; Intensive:46.5 %) with skeletal deformities. No significant interaction was found on the incidence of lordosis and fused vertebrae with the rearing tecnique. However, cranial abnormalities and kyphosis incidences were significantly higher in intensive system cultured red porgy. Also, the position of fused vertebrae in this fish was located mainly in the caudal area instead of pre-hemal area for semi-intensive system reared red porgy. Present results, suggest a relationship among feeding sequence, osteological development and deformity incidence and location in red porgy larvae