Influence of the food plant, Urtica dioica, on larval development, feeding efficiences, and voltinism of a specialist insect, Inachis io

The development and feeding efficiences of larvae of Inachis io were compared on mature and regrowth leaves of Urtica dioica . The nitrogen and water content of regrowth leaves was higher than in mature leaves. Larvae fed on regrowth leaves both singly and in groups attained higher ECI and ECD values, completed development faster, and attained a greater body weight than larva fed on mature leaves. AD values were not significantly different. The consequences on herbivore dynamics of the availability of good quality regrowth of food‐plants are discussed.