328 resultados para Lace bug


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Based on the observation of more than 10 000 leaves of plane trees, four populations of Corythucha ciliata (Say, 1832) (Heteroptera: Tingidae) are investigated. After having introduced some parameters derived from the data, we draw spatial-temporal patterns and describe the seasonal population dynamics of Corythucha ciliata. Amongst others, the temporal change of the density of population, the state plane of larvae–adults, the inclination to accumulate, and the intraspecific competition are examined. Population and biomass dynamics is characterized for populations with and without limited nutrient source in case of different weather circumstances and effects.

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Climate change affects on insect populations in many ways: it can cause a shift in geographical spread, abundance, or diversity, it can change the location, the timing and the magnitude of outbreaks of pests and it can define the phenological or even the genetic properties of the species. Long-time investigations of special insect populations, simulation models and scenario studies give us very important information about the response of the insects far away and near to our century. Getting to know the potential responses of insect populations to climate change makes us possible to evaluate the adaptation of pest management alternatives as well as to formulate our future management policy. In this paper we apply two simple models, in order to introduce a complex case study for a Sycamore lace bug population. We test how the model works in case the whether conditions are very different from those in our days. Thus, besides we can understand the processes that happen in present, we can analyze the effects of a possible climate change, as well.

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A rich collection of Heteroptera extracted with Berlese funnel by Dr. I. Loksa between 1953–1974 in Hungary, has been examined. Altogether 157 true bug species have been identified. The great majority of them have been found in very low number, there are only 27 species of which more than 10 adult individuals have been found. Some species considered to be rare or very rare in Hungary have been collected in relatively great number (Ceratocombus coleoptratus, Cryptostemma pusillimum, C. waltli, Acalypta carinata, A. platycheila, Loricula ruficeps, Myrmedobia exilis). The three families, which are more or less rich in species and have the highest ratio of extracted species, were Rhyparochromidae, Tingidae and Nabidae. Out of them, the family Rhyparochromidae has been found to be most diverse and most characteristic at the ground-level. Individuals of the families Tingidae, Hebridae and Rhyparochromidae have been found in greatest number. The occurrence of the lace bug Campylosteira orientalis Horváth, 1881 in Hungary has been verified by a voucher specimen. In respect to the environmental changes through the country, parallel changes have been observed in the zoogeographical distribution of the ground-living bugs.

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The lace bug, Leptopharsa heveae is an insect that causes serious damage on rubber trees. In laboratory condition, the strains of Verticillium lecanii (ARSEF 6430, 6431 e 6432) and Aphanocladium album (ARSEF 6433) were tested on third-and fifth-instar nymphs and adults of L. heveae to evaluate their virulence using 2.4 x 10(5) and 2.4 x 10(7) conidia/mL. The bioassays were carried out using Petri dishes whose inner bottoms were covered with damp filter papers. Each Petri dish contained five insects and one rubber tree leaflet. The plates were covered with PVC film to provide high relative humidity, maintained at 26 +/- 0.5 degrees C and a photophase of 14 hours. The Probit analysis was calculated from mortality date of insects killed by fungi. In the highest concentrations, ARSEF 6430 was more virulent for third instar nymphs, and the LT50 was 1.9 days. For the fifth instar, the strains ARSEF 6430, 6433 and 6432 showed similar virulence with LT50 of 2.6, 2.6 and 3.2 days, respectively. For adults, ARSEF 6431 was the most virulent strain with the LT50 recorded at 2.0 days. The smallest concentration did not always cause more than 50% mortality.

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The rubber tree lace bug, Leptopharsa heveae Drake & Poor occurs in high populations in rubber tree plantations and it is a limiting factor in rubber production due to the loss of photosynthetic tissue. The control of the pest has been made mainly with chemical products, which cause environmental contamination. The alternative would be the use of biological control agents, however, information about L. heveae natural enemies are scarce. The parasitoid Erythmelus tingitiphagus (Soares) parasitize eggs of the rubber tree lace bug. The aim of this study was to verify the occurrence of E. tingitiphagus in plantations of several rubber tree clones, located in Itiquira town, Mato Grosso State. The plant leaflets of the clones RRIM 600, PR 255, GT 1, PB 235 and PB 217 were collected weekly from October 2005 to February 2006. Parasitism was recorded during the entire study period. The parasitism rate of L. heveae eggs in the different clones ranged from 16.8 to 20.6%.

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Recently, Dictyla monotropidia Stal was observed feeding on plants of black sage (Cordia verbenacea Al. DC). The colonies of this insect were observed on abaxial surface of leaves, with nymphs and adults sucking the phloem sieve, causing spot, yellow aspect and leaf fall. D. monotropidia was already related as pest in other Cordia species in countries of Central and South America. Although, this is the first report of this insect attacking plants of C. verbenacea in Brazil.

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The tingid Leptopharsa heveae, known as the lace bug, occurs in large populations in rubber tree plantations, limiting the production of latex due to losses of photosynthetic area and weakening of the infested trees. The alternative for the use of insecticides would be the release of biological control agents, but little is known about the natural enemies of L. heveae. The parasitoid Erythmelus tingitiphagus parasitizes eggs of the lace bug in rubber tree plantations. The knowledge of the population dynamics and the peak of occurrence of economically important insect species and their natural enemies are indispensable requirements for the establishment of efficient and rational control strategies. The objective of this work was to study the population dynamics of L. heveae and E. tingitiphagus in rubber tree plantations in the county of Itiquira, MT, Brazil. Mature folioles were collected weekly from the lower stratum of the canopy of the tree clones RRIM 600, PR 255, GT 1, PB 235 and PB 217, from August/2005 to February/2006. The parasitoid was observed during the whole study period. The population peaks of the populations of the L. heveae and E. tingitiphagus in the study area occurred at the end of October and beginning of November. This result demonstrates that measures for the control of L. heveae and population increase of E. tingitiphagus must be adopted before the peak population of this pest in cultivated rubber plantations.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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As a third part of a series of papers on the ground-living true bugs of Hungary, the species belonging to the lace bug genus Acalypta Westwood, 1840 (Insecta: Heteroptera: Tingidae) were studied. Extensive materials collected with Berlese funnels during about 20 years all over Hungary were identified. Based on these sporadic data of many years, faunistic notes are given on some Hungarian species. The seasonal occurrence of the species are discussed. The numbers of specimens of different Acalypta species collected in diverse plant communities are compared with multivariate methods. Materials collected with pitfall traps between 1979–1982 at Bugac, Kiskunság National Park were also processed. In this area, only A. marginata and A. gracilis occurred, both in great number. The temporal changes of the populations are discussed. Significant differences could be observed between the microhabitat distribution of the two species: both species occurred in very low number in traps placed out in patches colonized by dune-slack purple moorgrass meadow; Acalypta gracilis preferred distinctly the Pannonic dune open grassland patches; A. marginata occurred in almost equal number in Pannonic dune open grassland and in Pannonic sand puszta patches.

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Background: The two-stage Total Laparoscopic Hysterectomy (TLH) versus Total Abdominal Hysterectomy (TAH) for stage I endometrial cancer (LACE) randomised controlled trial was initiated in 2005. The primary objective of stage 1 was to assess whether TLH results in equivalent or improved QoL up to 6 months after surgery compared to TAH. The primary objective of stage 2 was to test the hypothesis that disease-free survival at 4.5 years is equivalent for TLH and TAH. Results addressing the primary objective of stage 1 of the LACE trial are presented here. Methods: The first 361 LACE participants (TAH n= 142, TLH n=190) were enrolled in the QoL substudy at 19 centres across Australia, New Zealand and Hong Kong, and 332 completed the QoL analysis. Randomisation was performed centrally and independently from other study procedures via a computer generated, web-based system (providing concealment of the next assigned treatment) using stratified permuted blocks of 3 and 6, and assigned patients with histologically confirmed stage 1 endometrioid endometrial adenocarcinoma and ECOG performance status <2 to TLH or TAH stratified by histological grade and study centre. No blinding of patients or study personnel was attempted. QoL was measured at baseline, 1 and 4 weeks (early), and 3 and 6 months (late) after surgery using the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire. The primary endpoint was the difference between the groups in QoL change from baseline at early and late time points (a 5% difference was considered clinically significant). Analysis was performed according to the intention-to-treat principle using generalized estimating equations on differences from baseline for the early and late QoL recovery. The LACE trial is registered with clinicaltrials.gov (NCT00096408) and the Australian New Zealand Clinical Trials Registry (CTRN12606000261516). Patients for both stages of the trial have now been recruited and are being followed up for disease-specific outcomes. Findings: The proportion of missing values at the 5%, 10% 15% and 20% differences in the FACT-G scale was 6% (12/190) in the TLH and 14% (20/142) in the TAH group. There were 8/332 conversions (2.4%, 7 of which were from TLH to TAH). In the early phase of recovery, patients undergoing TLH reported significantly greater improvement of QoL from baseline compared to TAH in all subscales except the emotional and social well-being subscales. Improvements in QoL up to 6 months post-surgery continued to favour TLH except for the emotional and social well-being of the FACT and the visual analogue scale of the EuroQoL five dimensions (EuroQoL-VAS). Length of operating time was significantly longer in the TLH group (138±43 mins), than in the TAH group at (109±34 mins; p=0.001). While the proportion of intraoperative adverse events was similar between the treatment groups (TAH 8/142, 5.6%; TLH 14/190, 7.4%; p=0.55), postoperatively, twice as many patients in the TAH group experienced adverse events of CTC grade 3+ than in the TLH group (33/142, 23.2% and 22/190, 11.6%, respectively; p=0.004). Postoperative serious adverse events occurred more frequently in patients who had a TAH (27/142, 19.0%) than a TLH (15/190, 7.9%) (p=0.002). Interpretation: QoL improvements from baseline during early and later phases of recovery, and the adverse event profile significantly favour TLH compared to TAH for patients treated for Stage I endometrial cancer.

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Poem