Spatial distribution of damage caused by Heilipodus naevulus in a clonal eucalyptus plantation

Abstract

The species Heilipodus naevulus (Mannerheim, 1836) was detected, in 2008, in the municipal district Barão de Cocais, MG, in commercial plantings of eucalypt clones, damaging the main and the lateral pointer. Due to its night habit, its reduced size, grayish coloration, and, for sheltering in the litter area during the day, its detection is hindered, being its presence just evidenced through tumbled pointers. This work aimed to know the distribution of this species during the first year of eucalypt clones growth in order to supply subsidies for elaborating of a sampling plan. The work was carried out in the municipal district from Barão de Cocais, MG, from October/2008 to March/2009. The two plots of evaluation were stratified into lowland, slope and top. Were distributed 18 portions, of 10 x 10 trees, being nine per plot, and three for stratum. It was adopted as indicator of H. naevulus presence in the plant the pointer presence newly damaged. For calculating of the space distribution were used the Variance/Mean Ratio, Morisita Index, Parameter k of the negative binomial distribution, the Green's Coefficient, Poisson's Distribution and the Law of Taylor's potency. Along the evaluation period of the H.naevulus presence, the calculated indexes introduced an aggregated pattern of damage occurrence. That Indicates that the species presents a aggregated pattern distribution, even in low incidence.