Estrutura populacional, produção e biometria de frutos e sementes de Castanha-do-brasil (Berthollétia excelsa Bonpl.) na RESEX Rio Cajarí no sul do Estado do Amapá.

Resumo simples

Conhecimento ecológico local: o apaiari (Astronotus ocellatus, Agassiz 1831) na região dos lagos do município de Pracuúba, Amapá.

Resumo simples

Assessing the impact of climate change on the worldwide distribution of Dalbulus maidis (DeLong) using MaxEnt

For the first time, a model was applied at the global scale in order to investigate the effects of climate change on Dalbulus maidis. D. maidis is the main vector of three plant pathogens of maize crops and has been reported as one of the most important maize pests in Latin America. We modeled the effects of climate change on this pest using three Global Climate Models under two Representative Concentration Pathways (RCPs) using the MaxEnt software. Overall, climate change will lead to a decrease in the suitable areas for D. maidis. In South America, climate change will decrease the areas that are suitable for the pest, especially in Brazil. However, Argentina, Chile, Colombia, Ecuador, Peru, and Venezuela will have small areas that are highly suitable for the corn leafhopper. Outside of the pest’s range, Ethiopia, Kenya, Rwanda, Burundi, and South Africa also should be concerned about the risk of corn leafhopper invasions in the future since they are projected to have highly suitable conditions for this insect in some areas. This study will allow the relevant countries to increase their quarantine measures and guide researchers to develop new Z. mays varieties that are resistant or tolerant to D. maidis. In addition, the maize‐stunting pathogens for the areas are highlighted in this modeling

Standardized sampling plan for Aphis gossypii based on the cotton cultivar, plant phenology and crop size.

A standardized sampling plan is the starting point for developing a decision&#8208;making system for pest control. Aphis gossypii (Hemiptera: Aphididae) is a destructive sapfeeding pest on cotton worldwide. However, research addressing cotton cultivar, plant phenology and field size with the aim of developing a sampling plan for A. gossypii has not been done. Therefore, in this study, we developed a standardized sampling for A. gossypii as a function of these factors. To accomplish this, A. gossypii densities in four experimental cotton cultivars were sampled weekly during year one to determine the ideal aphid characteristic to sample (by individual or colony). During year one and two, A. gossypii densities were sampled weekly in the same cultivars to determine sampling unit, sampling technique and the number of samples for an A. gossypii sampling plan. Using the sample number determined, the sampling time was recorded for cotton field size of 1, 5, 10, 50, 100 and 150 ha in order to estimate the sampling cost. In cotton, the count of individuals was the best characteristic for the assessment of A. gossypii. Leaves of the most apical branches for the vegetative and reproductive cotton plant stage were the best sampling units. The best sampling technique was direct counting. The cotton cultivar did not affect the development of the sampling plan. The A. gossypii sampling plan involved the evaluation of 58 samples per zone and required 20 min (<0.35 min/sample) for the evaluation of these samples. However, the walking time between samples was the main factor responsible for the total sampling time and cost in cotton fields, and this factor strongly depends on the size of the cotton field