Gypsy Moth in Central Serbia Over the Previous Fifty Years

Abstract

The gypsy moth, Lymantria dispar L., after an unusually long latency period (30 years), has demonstrated all the characteristics of an outbreak in the forests of central Serbia three times since 1994. During the first outbreak (1994-1998), 24.8% of the broadleaf forests were endangered by the gypsy moth, during the second one (2002-2005), 18.8% of the broadleaf forests were endangered, and during the third one, which still ongoing, 2% of the broadleaf forests were endangeted. The average number of eggs in an egg mass ranged from 191.7 to 654.1. The percentage of vital and parasitized eggs in the total number of eggs ranged on average from 79.2 to 98.7 and from 0.5 to 20.0 respectively. During the observed period, in the gypsy moth populations, the activity of 56 natural enemies of this insect - 19 predators, 28 parasites, 7 parasites or saprophages and 2 pathogens - was reported. A higher mortality rate of the older gypsy moth larval instars was reported in the forest complexes of Belgrade and Valjevo region, in the culmination phase of the new outbreak. By field and laboratory studies of the causes of their death, the presence of conidia and resting spores of the entomopathogenic fungus Entomophaga maimaiga was reported in dead caterpillars. During every year of an outbreak, the gypsy moth was suppressed in the egg stage, and in the larval stage during the culmination phases.