Flutuação populacional de Rhynchophorus palmarum, Metamasius hemipterus, e do nematoíde Bursaphelenchus cocophilus em plantios de dendê (Elaieis guineensis Jacq) em Roraima

Abstract

The objective was to study the population dynamics of Rhynchophorus palmarum, Metamasius hemipterus cocophilus Bursaphelenchus in culture and oil palm in two environments Roraima. The experiment was conducted in two areas of Embrapa Roraima, one in the search field in Boa Vista in the region of Monte Cristo (Savanna area) and the other in the city of California Farm Caroebe, southern state of Roraima (forest area) . A Sampling is performed using bucket traps containing pheromone aggregation pheromone attractive food and cane sugar. Every 15 days the specimens captured were taken to the Entomology Laboratory of the Federal University of Roraima for counting, sexing and evaluation of nematode Bursaphelenchus cocophilus population. The data on population fluctuations of insects and nematodes were subjected to descriptive statistical analysis and correlation and multiple linear regression using the Statistica 7.0 computer application. To verify the existence of a correlation between the abundance of Bursaphelenchus cocophilus Climatic factors and observed values were calculated "r" (Pearson correlation coefficient) and the test "t" test at 5% probability to ascertain their significances. Was verified a higher incidence of Rhynchophorus palmarum in February and September 2011, and January 2012, and Metamasius hemipterus in March 2011 in savanna environment. There was a higher incidence of Rhynchophorus palmarum in the months of March, April and September 2011 and January 2012, and Metamasius hemipterus the months of August, September and December 2011 in a forest environment. The work led to the following conclusions: The population density of Rhynchophorus palmarum occurs similarly in savanna environment and forest in Roraima. The abundance of Rhynchophorus palmarum and Metamasius hemipterus in savanna environment is adversely affected primarily by the relative humidity and the air temperature, respectively. The abundance of Rhynchophorus palmarum and Metamasius hemipterus the forest environment in Roraima, is not directly influenced by rainfall, average temperature and relative humidity of the air. The population density of Bursaphelenchus cocophilus in Rhynchophorus palmarum is significantly larger in the forest than in savanna. The population density of Bursaphelenchus cocophilus in Metamasius hemipterus not differ between forest and savanna habitats. The frequency of nematodes between males and females in Rhynchophorus palmarum is similar. The population density of the species Bursaphelenchus cocophilus, Rhynchophorus palmarum and Metamasius hemipterus in forest and savanna habitats, was not directly correlated, in the period studied, with the rainfall, average temperature and relative humidity.