Avaliação de danos causados por insetos em sementes de Andiroba [(Carapa guianensis Aubl.) e Andirobinha (C. procera DC.) (Meliaceae)] na Reserva Florestal Adolpho Ducke em Manaus, AM, Brasil

Abstract

Andiroba (Carapa guianensis Aublet) and andirobinha (Carapa procera DC) (Meliaceae) are important species in the Amazon, which are commercialy exploited because of its wood quality (after Mogno) and the oil extracted from the seeds. In these species, the survival is threatened by insect predation on the seeds and sprouts. The seed predation influences the structure of the population by changing the number of seeds and its distribution, which are important to regeneration. From february to june, 2006, a seed predation study about Carapa guianensis and C. procera was conducted in five different plots (two plots with each type of andiroba and a mixed plot) in Reserva Florestal Adolpho Ducke, Manaus AM. The seed samples from the ground were taken weekly and the canopy samples, from three different heights (vertical stratification), were taken monthly, inside each plot. From march to may 2006, monthly, 30 non-predated seeds and 30 predated seeds, collected from the ground of each plot, were taken to the laboratory to observe germination, during a month. The results show that Hypsipyla grandella and H. ferrealis (Lepidoptera: Pyralidae) are the main insect species associated to seed predation in C. procera and C. guianensis, presenting predation mean rates of 39% to 61,96%, respectively. Fruit and seed predation were observed inside the canopy stratification of the two Carapa species. Hypsipyla ferrealis and H. grandella presented high predation rates in the lower third of the tree canopy, when compared with the other two superior thirds. Hypsipyla grandella was observed only in the lower third of the tree canopy of the two types of Carapa. The seed predation in C. procera and C. guianensis reduced the germination process, from 47,77% - 90% in non-predated seeds to 8,88% - 17,77% in predated seeds, which reduces the number of seeds for regeneration. This study presents important information about C. procera, C. guianensis and, H. grandella and H. ferrealis that can be used in the conservation and management of the species.