File: Size of this preview: × pixels. Other resolutions: × pixels | × pixels | 1, × Determinacao de danos da cigarrinha-das-pastagens (Deois incompleta) a Brachiaria humidicola E.B. decumbens . Silva, A.B.. Access the full text. Cigarrinhas-das-pastagens, Zulia entreriana (Berg, ) (Homoptera, Cercopidae), no norte do Estado de Minas Gerais. II. Controle de ninfas com inseticidas.
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Cohorts with variable numbers sas D. In contrast, sparse rainfall keeps postdiapause eggs quiescent, and hatching occurs asynchronously over a long period of weeks in accordance with the distribution of precipitation.
Cigarrinha-das-pastagens (Pasture planthopper) | Project Noah
The data suggest a lack of pattern related to the geographical position of the traps. D] h in the laboratory from May to August Sujii et al. The proportion of postdiapause eggs starting final embryonic development increased as daas consequence of exposure to increasing periods of moisture in condition 1 Fig. Eggs that did not hatch and became flat and black were considered dead for the mortality evaluation. Bars represent only the time spent in condition 3.
During the months of April and May in and end of the third population peakD. Hostplantand seasonal abundance patterns of some Citarrinha Chry-somelidae. The insect’s dxs history strategy includes survival over the dry season May-August as diapausing eggs, and risk distribution bet-hedging pasgagens which females vary both the proportion of diapausing eggs and the duration of the dormancy in its progeny Fontes et al.
Our goal was to understand how mortality rates vary during D. To model the proportion of eggs resuming embryonic development as a function of moisture exposure time, a graph of the accumulated proportion of embryos that resumed development was constructed. The low mortality rates of eggs observed during the middle of the dry season July and August indicate that lack of moisture and warm soil do not preclude outbreaks of D.
The last hatching, in this pastavens of eggs continuously exposed to moisture, occurred after 38 d. The plants were observed three times weekly, and examined for the presence of first instars. The base of the cage was buried 10 cm deep to impede the entrance of soil insects from beneath.
Predicted mortality of eggs in final stage of em-bryonic development and of newly emerged nymphs of D. Eggs in the final stage of embryonic development are also susceptible to desiccation. Migration may have a role in this dynamics except in some cases, such as outbreaks and local extinction. Records about the position and development stage of nymphs were made every d following Sujii Comparisons with field data demonstrated a close fit to the observed and expected proportion of nymphs hatching daily.
Increasing exposure to low moisture progressively raised mortality rates of newly emerged nymphs and embryos Fig. Cages consisted of cylindrical iron frames 0. Cohorts of 50 eggs were placed in a cm-diameter petri dish containing a layer of cotton covered with moist filter paper.
Resumo Spittlebugs are the main pests of pasture of America Tropical, among which the genera Deois and Mahanarva stand out.
The proportion of these that died from pastsgens hydric stress of condition 2 was detected under condition 3. Se ensayaron 6 insecticidas para evaluar el grado de eficiencia en el control de Deois incompleta, principal plaga de los pastos en la Amazonia. No tags from this library for this title.
Sign In cigaerinha Create an Account. The last egg hatching in this group allowed the estimation of the time necessary under moist conditions to induce all eggs of a population to start final embryonic development. Each cohort was protected from predators by cages consisting of a wooden frame 0. The movement of marked and recaptured populations was monitored with non-toxic fluorescent powder.
Observations stopped when all surviving nymphs reached the second instar. A control set of eight pots was kept under daily irrigation throughout the experiment.
With this procedure, it was possible to distinguish the proportion of eggs that resumed final embryonic development in response to different periods of exposure to moisture condition 1 from those that were naturally infertile.
This study is part of a Ph. For commercial eas, please contact journals. In this work we evaluated mortality rates during three distinct stages of spittlebug development: Tags from this library: In the current study, we propose a model that explains how different combinations of precipitation and drought periods at the beginning of the rainy season can influence the mortality of eggs in the final embryonic stage and of newly emerged nymphs. Movements of migration and dispersion of adult pasatgens.
Related articles in Web of Science Google Scholar. A proportion of 4: Time taken for eggs of D. Each treatment had eight replications. Metadata Mostrar registro completo. Environmental factors affecting spittle-bug egg survival during the dry season in central Brazil.
Document Collection CINFOS Close shelf browser No cover image available No cover image available No cover image available No cover image available No cover image available No cover image available Effect of two levels of dry ipil-ipil leaves on growth performance and carcass characteristics of bulls Forage production from koobabool Leucaena luecocephala Lam. Pasfagens these data, we conclude that M.