Distribuição e amostragem de ninhos de formigas cortadeiras em talhões de eucalipto em Três Marias, Minas Gerais, e Monte Dourado, Pará / Distribution and sampling of nests of leaf-cutting ants in eucalyptus stands in Três Marias, Minas Gerais State, and Monte Dourado, Pará State

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The objectives were to evaluate the distribution of nests of leaf-cutting ants and their areas of mound soil in Eucalyptus spp. stands according to their distance from the borders of these stands in monocultures of this plant in the areas of Três Marias, Minas Gerais State and Monte Dourado, Pará State, Brazil. Thirty eucalyptus stands were evaluated where the nests of leaf-cutting ants and their areas of mound soil from the nearest border of the eucalyptus stands were identified. The effect of the distance from these borders and the distribution of their areas of mound of soil were analyzed with two methodologies: the accumulated percentage of nests of leaf-cutting ants and their areas of mound soil in Monte Dourado, Pará State and the analysis of the identity models for both areas. Equations were generated to estimate the densities and the areas of mound soil of nests of leaf-cutting ants in 10 m strips from the borders of each eucalyptus stands for both areas. The analysis of the identity models showed no differences in the distribution of nests of leaf-cutting ants and their areas of mound soil between the 10 meters strips from the borders of the eucalyptus stands. This test showed low variation between the observed and the estimated numbers of nests of leaf-cutting ants and their areas of mound soil but the low infestation levels of all of them per class center shows that the monitoring system is working satisfactorily for the area of Três Marias, Minas Gerais State. The analysis of the distribution of nests of leaf-cutting ants and their areas of mound soil in the eucalyptus stands with the method of the accumulated percentage showed larger concentration of nests of this pest in areas closer to the borders of the eucalyptus stands in Monte Dourado area, Pará State. The number of nests of leaf-cutting ants with bigger areas of mound areas and the significant increase on the percentage of the distribution of this last parameter did not permit to affirm that the larger concentrations of them exist at certain distances from the borders of the eucalyptus stands. The presence of adult nests of leaf-cutting ants can be tolerated without economic damages, but the high areas of mound soil in some eucalyptus stands in Monte Dourado indicate the necessity of revising the methodology of controlling nests of leaf-cutting ants in the stands of eucalyptus stands in this area. The different results of the border effect in the distribution of nests and the area of mound soil of leaf-cutting ants on the methodology of evaluation used indicates that the test of the identity models was not adequate to evaluate this behavior at different distances from the borders or the eucalyptus stands (at each 10 m).

ASSUNTO(S)

formiga-cortadeira sampling monitoring leaf-cutting ants zoologia aplicada monitoramento amostragem sequencial

ACESSO AO ARTIGO

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