Effects of Cadmium on Phenotypic Plasticity Index Change in Lymantria dispar L. Gypsy Moth

Abstract

This work examines the effects of cadmium on changes to the index of phenotypic plasticity during the larval development in gypsy moth. Control group without cadmium supplements and three cadmium-fed groups were formed: C1 (10 μg Cd/g dry weight), C2 (30 μg Cd/g dry weight) and C3 (50 μg Cd/g dry weight). Evaluation of the index of phenotypic plasticity was performed according to Cheplick’s and Lee’s method. Index comparison according to Lee has determined the statistically significantly higher value in group C1 in relation to C2 during the larval development until third instar, and in group C3 in relation to C1 during third instar. Additionally, higher values in group C1 in relation to C2 have also been determined until the fourth instar. Phenotypic index value comparison according to Cheplick has determined significantly higher values in group C1 larvae in relation to C3 during the larval development until the third instar, whereas groups C2 and C3 yielded values higher until the fourth instar. Aforementioned traits and their values in group C3 were recorded as negative which suggests that cadmium presence in the environment during certain stages of larval development can be of significant effect to direction of changes in phenotypic plasticity.