Determination of Gypsy moth populations in the forest

Abstract

In a state forest of Eure-et-Loir, two methods for estimating gypsy-moth egg-mass densities were compared. A relationship model between the " classic method " (time expensive : 2,5 hours for 25 ha) and the " five minutes " one (all the egg-masses seen are counted during a straight walking of 5 minutes) was etablished from data of 14 woodplots. With only a walking for 5 ha, a reliable defoliation risk estimation is obtained. This method shares out the spent time by 5.