CIGARRINHA DAS PASTAGENS PDF

Spittlebugs species Hemiptera: cercopidae in middle-north of MatoGrosso state, Brazil. Palavras-chave: Deois flavopicta, Mahanarva fimbriolata, Zulia entreriana , pastagem. This work was carried out to identify the main spittlebugs species occuring on cattle producing area in Middle-North of Mato Grosso State. Key words: Deois flavopicta, Mahanarva fimbriolata, Zulia entreriana , grassland. Com base nos resultados obtidos no presente trabalho pode-se concluir que D.

Author:Sagami Tudal
Country:Colombia
Language:English (Spanish)
Genre:Politics
Published (Last):26 May 2005
Pages:211
PDF File Size:18.57 Mb
ePub File Size:9.76 Mb
ISBN:934-3-29357-538-3
Downloads:68478
Price:Free* [*Free Regsitration Required]
Uploader:Mazuhn



Survival and injuries of Deois flavopicta Stal. The present study evaluated the survival and injuries of Deois flavopicta Hemiptera: Cercopidae in pastures of Urochloa Syn. Brachiaria decumbens and U. Sowing was manual, with Twenty adults were released on the plot, in a 40x40x70 cm cage, forty-nine days after sowing.

The insects were sampled every two days during twelve days, without replacement of dead insects. Injuries caused by the spittlebug were evaluated by a rating scale and by productivity dry mass yield. The survival of adults was higher in the U. Results show that seed treatment with thiamethoxam reduced the survival of D. Brachiaria decumbens e U. A semeadura foi realizada manualmente, distribuindo 12,0 kg ha -1 de sementes. Extensive culture of Urochloa syn.

According to AUAD et al. Further, the species D. Female spittlebugs usually lay their eggs on the ground or in vegetal remains. Adults feed on the aerial section of the grass and inject it with toxins, giving it a yellowish color and causing it to wither.

They also reduce crude protein, fat and essential minerals. Dry matter increases and the grass becomes less tasty. In other words, decrease of pest population is a must.

Liabilities are estimated in hundreds of millions of dollars a year. However, high costs impair control measures, as well as lack of information and scarcity of specific insecticides against the spittlebug, scanty tolerant or resistant foragers, difficulties in acquisition and inconsistent results of biological control TOWNSEND et al. Insecticides are frequently and mistakenly applied after the yellowing of pastures, as the symptom appears approximately three weeks after the spittlebug attack SOUZA et al.

One of the most important characteristics in the treatment of seeds by insecticides is the systemic effect on the plant, enhanced by low vapor pressure and solubility in water of the main active substances.

In fact, the ingredient releases itself slowly and is absorbed by the roots. Current analysis evaluates the dry mass yield and the survival and injuries caused by adult spittlebugs D. Experimental design comprised randomized blocks with six treatments 2x3 and four replications. Each parcel was made up of eight sowing rows, spaced 0. Treatments consisted of two species of signalgrass U. Soil correction and preparation were undertaken in an area with remnant pasture for the establishment of the field assay.

Duly registered for signalgrass seed treatment, the products were applied to the seeds immediately before sowing, with broth volume proportional to mL kg -1 seeds, following technical recommendations ANDREI, The seeds were placed in plastic bags, which were filled with air and sealed.

These were the recipients in which pesticide and seeds were shaken and homogenized. After drying, seeds were sown manually with a distribution of Moreover, the establishment of the field assay was carried out taking into account favorable soil-climate conditions for the implantation of pastures. Spittlebug adults D. Insects were then selected in the laboratory and 20 specimens were inoculated per parcel in a 0.

The emergency of plants stand was evaluated at each parcel, recording the number of plants present in 0. Survival of D. Rates were converted into percentages of surviving spittlebugs, at each evaluation, proportional to the initial population. Yield was calculated by signalgrass cutting and weighing of green mass. Dry matter was then weighed.

Evaluation occurred 70 days after sowing and data were converted into kg m Analysis of variance showed that there was no significant interaction among the signalgrass species and insecticide-treated seeds on the survival of D. E: species of signalgrass. TS: treatment of seeds. However, overtime on the 10 th and 12 th DAI a greater percentage of spittlebugs survived in U. The treatment of signalgrass seeds by insecticides fipronil and thiamethoxam failed to decrease D.

Therefore, on the 6 th DAI, the systemic insecticide thiamethoxam significantly reduced the percentage of the surviving insects when compared to foragers without any chemical protection of the seeds.

It also reduced those submitted to seed treatment with fipronil. Impact of thiamethoxam on cercopid adults remained during the other evaluations at 8 th , 10 th and 12 th DAI.

The above may be related to the systemic activity of thiamethoxam with great efficaciousness in the control of sucker insects GAZZONI, The number of U. TS: Treatment of seeds. DAS: Days after sowing.

Injuries attributed to the forager attacked by spittlebug adults in the susceptible grass U. The above corroborates the resistance of U. Fipronil and thiamethoxam, applied in the treatment of signalgrass seeds, failed to reduce significantly injuries by D.

Since there was a decrease in survival rates in grasses from seeds treated with thiamethoxam, it may be surmised that similarity in injuries perceived among the experimental units was probably due to high infestation rates 20 adults 0. During evaluation of the pest-insect, yellowing of the grass was perceived on the 2 nd and 4 th day after infestation. Dry matter yield was significantly similar among species U. However, the yield of the resistant signalgrass was 9.

The treatment of signalgrass seeds with insecticide thiamethoxam may be an asset in decreasing the population of D. However, it does not affect injuries caused by the pest insect and dry matter yield. AUAD, A. Biologia e ecologia de pragas das pastagens. Boletim de Pesquisa, 7. Methods used to screen maize for resistance and to determine mechanisms of resistance to the Southwestern cornborer and fall armyworm.

Toward insect resistance maize for the third world. Mixed risk-spreading strategies and the population dynamics of a Brazilian pasture pest, Deois flavopicta Homoptera: Cercopidae. Journal of Economic Entomology , v. Grazing management as a means of regulating spittlebug Homoptera: Cercopidae numbers in Central Brazil. Economic damage causaed by spittlebugs Homoptera: Cercopidae in Colombia: A first approximation of impact on animal production in Brachiaria decumbens pastures.

Neotropical Entomology , v. Revista Brasileira de Zootecnia , v. Tratamento de Sementes. Access on: Jun 18 The damage capacity of Mahanarva spectabilis Distant, Hemiptera: Cercopidae adult son Brachiaria ruziziensis pasture. Scientific World Journal , p. Seed News , Pelotas, n. Pragas das pastagens. Belo Horizonte: Epamig, Effect of host plant on the fecundity of spittlebug Deois flavopicta Stal Homoptera: Cercopidae : implications on population dynamics.

Documentos, Access on: Apr 09 Campo Grande: Embrapa Gado de Corte. This is an open-access article distributed under the terms of the Creative Commons Attribution License. Services on Demand Journal. Application of the products Duly registered for signalgrass seed treatment, the products were applied to the seeds immediately before sowing, with broth volume proportional to mL kg -1 seeds, following technical recommendations ANDREI, Infestation of adult D.

Evaluation and data analysis The emergency of plants stand was evaluated at each parcel, recording the number of plants present in 0. Treatment Days after infestation 2 4 6 8 10 12 U. Treatment Stand - Plants. Received: September 23, ; Accepted: April 19, How to cite this article.

EPEC 2024 PDF

Cigarrinha-das-pastagens (Pasture planthopper)

.

CAE GOLD EXAM MAXIMISER PDF

.

Related Articles