Method for monitoring nymphs of cicadas and control with insecticides in reforestations with paricá

O objetivo deste trabalho foi estabelecer um método para o monitoramento da população de cigarras (Quesada gigas) e para a avaliação da eficácia de doses de thiamethoxam, carbofuran e imidaclopride no controle de ninfas, em reflorestamento com paricá (Schizolobium parahyba var. amazonicum). Foram utilizadas as seguintes dosagens de inseticidas: 2,0, 4,0 e 6,0 kg ha-1 do produto comercial Actara (250 WG), para o princípio ativo thiamethoxan; 7,15, 14,30, 21,45 L ha-1 de Furadan (350 FS), para o carbofuran; e 4,5, 9,0, 13,5 L ha-1 de Provado (200 SC), para o imidaclopride. As três dosagens de cada produto foram aplicadas em área total. Foram realizadas três avaliações quinzenais, posteriores à aplicação, em que foram contabilizados os números de buracos e de ninfas vivas, por meio da abertura, com implemento tratorizado, de trincheiras com 7 m de comprimento, 0,8 m de largura e 0,07 m de profundidade. Todos os princípios ativos testados foram eficientes na redução da população de ninfas de Q. gigas, mas não houve efeito significativo das doses avaliadas. Os princípios ativos carbofuran e thiamethoxan são os mais promissores, com controle de 75–80% da infestação de ninfas. A abertura de trincheiras com o implemento tratorizado é eficaz no monitoramento da população de ninfas de Q. gigas, em reflorestamentos com paricá.The objective of this work was to establish a method for cicad (Quesada gigas) population monitoring and for the evaluation of the effectiveness of thiamethoxam, carbofuran and imidacloprid doses on the control of cicad nymphs, in reforestation with paricá (Schizolobium parahyba var. amazonicum). The following insecticide doses were used: 2.0, 4.0, and 6.0 kg ha-1 of Actara (250 WG) commercial product, for thiamethoxam active principle; 7.15, 14.30, and 21.45 L ha-1 of Furadan (350 FS), for carbofuran; 4.0, 9.0, and 13.5 L ha-1 of Provado (200 SC), for imidacloprid. The three doses of each product were applied in the total area. Three biweekly evaluations were done after the applications to assess the number of holes and live nymphs, using a tractor implement to open trenches with 7.0-m length, 0.8-m width and 0.07-m depth. All active principles tested were effective in reducing Q. gigas nymph population, but there was no significant effect of the evaluated doses. Carbofuran and thiamethoxam active principles were the most promising ones, with 75–80% of nymph infestation control. The trench opening with the tractor implement is effective for monitoring Q. gigas nymph population in reforestation with paricá

Some characteristics of the nocturnal atmospheric surface layer structure and CO2 releasing above Caxiuanã Amazonian rain forest

Some characteristics of the nocturnal boundary-layer (NBL) above the Caxiuanã Forest, Pará, are investigated. Rawinsonde, tower fast-response and vertical profile data obtained during wet and dry seasons have been used. Turbulent series of wind velocity components, CO2 concentration, specific humidity and temperature, show that wind gusts events have an important influence upon the variability patterns of the foret-atmosphere interaction. A possible mechanism relating wind gusts with cloud outflows has been detected. It was observed an important fall in equivalent potential temperature, θe, vertical profile values during gust events. Like-ramp coherent structures in the scalar turbulent time series were also observed during the wind gusts, and have been investigated with wavelet analysis. It is shown that gusts are associated with strong exchanges between the forest and the atmosphere and have important effects upon the scalar structure above and within forest canopy. They are also associated with sampling errors enhance in scalar eddy-correlation flux calculations. Five minutes covariance time integration have demonstrated that wind gusts are responsible for considerable parcels of the nocturnal total forest-atmosphere scalar exchanges, particularly in CO2 releasing. Turbulent CO2, water vapour and temperature time series and net radiation (Rn) data have been used to classify the NBL evolution. Results show that like-ramp coherent structures are present in almost all investigated data and Rn changes are often associated with variations in the surface layer turbulence structure. These results are interesting to understand physical processes which stabilize NBL and probably generate favourable conditions for low level jets occurrence.Pages: 2059-206