INFLUENCE OF MICROCLIMATIC VARIATIONS ON EAG RESPONSES OF LYMANTRIA-DISPAR (LEPIDOPTERA, LYMANTRIDAE) MALES TO SEX-PHEROMONE

The gypsy moth Lymantria dispar; like many other forest defoliator spe cies, exhibits periodic population outbreak dynamics, whose variabilit y in different years and in different places can be attributed to diff erent microclimatic parameters. This study was focused on the correlat ion between climatic variations in two different localities of Sardini a over a three-year period and on changes in sensitivity of the male a ntennal olfactory receptors. Our electrophysiological results show tha t olfactory EAG responses to the sex pheromone of the antennae are inv ersely correlated with rainfall during gypsy moth larval development. On the other hand, male antennal sensitivity and ambient temperature w ere not correlated, possibly due to the fact that no significant clima tic variations were detected in the period examined. Our findings, esp ecially for rainfall, are in good agreement with data in the literatur e concerning the effects of weather on gypsy moth population dynamics.